ICYMI: Mortal Hydration products are soon going to be replacing Gatorade Endurance at an IRONMAN race near you. Gatorade (regular formula) will be available on North American courses, alongside Mortal Hydration samples, until the end of June. Starting in July, it's all Mortal Hydration, all the time. If you’re considering making changes to your nutrition plan because you intend on “living off the course” on race day, and you’ve heard that on-course nutrition is changing, I recommend keeping a troubleshooting guide handy. It pays to know how to adapt when things go sideways.

Before we dive into how to think about living off the course on race day depending on what’s on your course, we need to define a couple things. First “living off the course” means to me: getting all or most of your nutrition and hydration needs from products available at feed zones on the side of the course. Quick refresher: there are three primary constituents of solid endurance sport fueling: Carbs, sodium, and water. Carbs for energy. Sodium and water for hydration. One without the other does not lead to better hydration. You need to have both. And you need to have adequate hydration to be able to absorb your carbs. And, finally, you need to be consuming carbs to sustain your energy. These things all become increasingly true the longer the race goes beyond about two hours. Usually, feed zones have these things in abundance. Usually. And usually, they don’t have much else.

Here, I’ll hit you with the summary up front: if you’re living off the course with Mortal Hydration only, you’ll be disastrously under-carbed. Hypoglycemic. Hungry, shaky, and under-performing on the bike. Things will go from bad to worse on the run. But at least you’ll be hydrated! There is a fair amount of sodium, and if you’re trying to get a meaningful amount of carbs (energy) from Mortal, you’re going to be taking in plenty of sodium with even their low sodium mix (just over 400 mg sodium per 10 grams of carbs). Friendly reminder: you probably need a whole lot more than 30-40 g of carbs per hour for activities lasting longer than 3-4 hours. Try 80-120g per hour. Consuming less than half of what is needed for optimal energy maintenance is usually catastrophic. You’ve been warned.

If you opt instead to bring your own fuel concentrate or drink mixture on course, you’ll be able to custom blend it to whatever energetic hydration perfection you need. Home brew comes with the need to either carry powder with you, or concentrate one or more of your bottles with powder beforehand with your preferred ratio of carbs and sodium.

How many carbs? Well, there's a video for that.

And sodium.

When your gut is on the brink, the devil is in the details. And guts are usually on the brink, on race day. If you care about race performance, you’ll care about the details. So, let’s dive into strategy. Hang with me here. To do performance nutrition well, you’re going to need your calculator — or an app or coach that does all the math for you.

Our Race Day Scenario and Math

Let’s assume a 6-hour 70.3 goal. And it’s warm-but-not-hot. Call it 77°F for those of us in the northern hemispheres. I mention the duration of your race because exercise duration is the first thing that you should consider when you think about how much carbohydrate you need per hour. And your estimated thermal stress (how hot you’ll be) should be your next consideration because it informs you about how much fluid and sodium you’ll need to consume.

For math simplicity’s sake, I’m going to say we’re targeting 90g carbs per hour, 900 mg sodium per hour, and 900 mL fluid consumption per hour. Maybe it’s 700 mL in the first hour of the bike because it’s cooler then, but then it shifts to 1000-1100 mL in the final hour of three hours on the bike because the sun is starting to beat down. Then, your gut will only tolerate, say, 900 mL/hr on the run. That all adds up to a tidy 900 mL per hour. The rest of the consideration surrounds two golden questions:

How do I get my 90 grams of carbs per hour?
How do I get my 900 milligrams of sodium per hour?

Let’s be generous, and say in the real world, it’s your “A” race and you’ve got an estimated ±15% variance in what you can actually consume and get away with, without causing serious performance trouble. Higher consumption than that upper bound than that – ~105g/hr carbs or ~1100mg/hr sodium – and you get debilitating gut distress. Lower and you get either hypotensive from dehydration or low-energy and shaky from neurogenic hypoglycemia. That’s the scientific name for “I’m irritable, low-energy, possibly-crying, definitely shaky and maybe cold-sweating, probably starting to get ravenous” which comes from insufficient energy consumption. (In reality, you can probably overshoot sodium by as much as 30-50% and be okay. Do that with carbs, and you may be looking for the nearest restroom.)

And one more FYI before we get to the exactly how-to section: whether you’re targeting a 5-hour 70.3 or a 7-hour 70.3, your intake rates – per hour – might still be the same, so this example should hold for most folks. So, how do we get the necessary sodium and carbs by living off the course at our favorite long course triathlons? Let’s find out.

Hitting Performance Targets

For our scenarios, we are going to do a series of evaluation steps: first, we’re going to figure out how many servings of each product would need to be consumed to hit our carb target. Then figure out how many servings would be needed to hit our sodium target. Then calculate if that’s feasible at manufacturer prescribed – or bottled – concentrations. As in, how much fluid would that need to be with, if you listen to the manufacturer. Then, see what it would take to modify with any other on-course-available products or strategies. And finally, figure out what else we’d need to carry to compensate for any shortcomings in the aid station-stocked products.

I discuss primarily the bike leg, but this all applies to the run leg at the same hourly rates. Except that your wiggle room for error gets tighter, and your carb needs might have to shift down about 20% per hour. Maybe. Some folks can keep right on slamming carbs during the run, too.

Racing with Mortal Hydration

I’m just going to hit you with this up front. Mortal Hydration is a hydration product. Not a fuel product. Read: not for energy! Yes, there are a few carbs in it. (10g to be exact). But they are so limited that our example here is quickly going to turn into a “must-add-carbs-or-else!” optimization problem. The alternative is that you don’t finish your race, probably cry at least once, and maybe swear more than you usually do. The second alternative would be to WAY overdose sodium and have a really funky stevia-tweaked flavor trying to get carbs from what is not meant to be a meaningful fuel source.

To get to 90g/hr, we’ll need to divide 90 grams per hour by 10 grams per serving, which comes out to 9 servings. That’s 9 servings of Mortal Hydration to hit 90g/hr carb consumption. I highly recommend NOT doing that. Your sodium intake and flavor intensity will be insane. (Or you’ll drink an egregious amount if mixing at manufacturer recommended doses).

To hit 900 mg/hr sodium you’ll take 900 mg sodium per hour, and divide by either around 450 or 900 mg sodium per serving, which yields: 2, or 1, serving(s) of Mortal Hydration, to hit target sodium consumption, depending on if you’re using Mortal’s “normal” or “Salty” blends. There are three flavors of each. The dark-mode colored packaging are the “salty” ones, FYI!

Just for fun, let’s assess how much fluid we need to be consuming to hit our carb and sodium targets with Mortal Hydration.

For carbs: 9 * 22 oz per serving (derived from the adequate carbs scenario) gives a whopping – and totally impossible – 198 oz per hour.

For sodium: 1 serving (salty) or 2 servings (normal) * 22 oz per serving gives us either 22 or 44 oz of fluid per hour, if mixing at recommended strengths, which Mortal recommends more strongly than just about any other company. They mention “athletes are making a fatal mistake: over scooping their hydration.” Turns out, you’ll actually want to over-scoop Mortal’s “normal” mix if you’re needing 900 mg/hr (which is a pretty modest need for a 6-hour event.

If you’re trying to get carbs from Mortal, you are out of luck. If you are trying to get sodium, you’ll probably need to over-scoop their normal mix beyond what they recommend, but their “salty” mix might do the trick mixed in whatever fluid amount you like or at manufacturer-recommended mixing instructions.

Let’s say we decide to use the Mortal “Salty” mix. Pomegranate flavor because that’s Michelle’s favorite. (We have no affiliation with Mortal, although TheFeed.com did send us a big package of every version to try. It’s okay-ish. We’ll get through it eventually.)

Let’s put that 900mg Mortal Hydration “Salty” single serving in a 22 oz bottle because that’s what they say to do. (Let’s assume that’s what they’re doing on the side of the Ironman courses, where it is now a standard mix.) We’ve now met our sodium needs.

We’ll also need to make sure we’ve got another 8 oz of water onboard somewhere for this hour, and another 8 for each subsequent hour. (8 oz + 22 oz = 30 oz, which is roughly 900 mL, our hourly fluid target.)

That leaves us approximately – no, exactly – 80 whopping grams (which are the same as regular grams) of carbs short, per hour. We’re going to need to source an additional 80 grams per hour times 3 hours on the bike. That’s 240 grams of carbs over three hours. 8-10 bananas from aid stations should do the trick! Or 10 Maurten Gel 100s, or 12 Quantum Energy Squares. I don’t recommend you use bananas. I also probably wouldn't use that many Energy Squares, with their caffeine. But if you’re going to live off the course, using Mortal, you’re also going to have to use the other carb options — and grab a lot of them.

If you don’t the result will be catastrophe. Please tell your friends.

Now, let's optimize this solution by bringing something with us.

Since the carb need is so high, the most straightforward would be to carry your own bottle of concentrated fuel mix. 80 grams per hour worth, to be exact. That’s a serving of most beverage products plus 1 cup of table sugar, or half cup of maltodextrin, half cup of fructose.

Alternatively, there are many other gel sources you can bring for your on course nutrition. Just make sure you bring a lot if you plan of supplying your own — 240g of carbs worth.

Building Your Own Fuel to Avoid Mortal

Alright. So perhaps you have a stevia sensitivity. Or you just don't like what I described above, and you want to be more self-reliant out of the gate. Let's home-brew a solution that solves for this problem. To start with carb needs, I usually do one serving of any product I like the flavor of, and then sugar for the rest. It might look like 1 rounded scoop of Gatorade (which is a little over 60g carbs, call it 70g) plus a cup of sugar (200g carbs). That’s 270 grams of carbs. Perfect. You can also do any ratio of maltodextrin to fructose you like or dextrose to fructose. Somewhere between 2:1 and 1:1 is probably a good idea. Flavor and experience are the only driving factors.

On sodium: Two teaspoons of sodium citrate or one teaspoon of table salt gets you about 2000 mg sodium. Use sodium citrate for all or part of it if you want it to be as easy on your gut as possible. Chloride ions in excess are sometimes gut-offensive. I might shake a little more table salt in there just for fun and flavor and to bump me up to the needed 2700 mg (900 mg per hour times three hours!) sodium in the concentrated bottle.

Getting all the fluid: Drink a third of the concentrate bottle per hour, for three hours straight. Call it a 1000 mL reservoir. You consume an additional two 900-mL bottles of water, splitting each over 1.5 hours. You’ve hit your 2700 mL fluid intake goal perfectly. There is no need to modify with anything on-course. Fill up fresh water as needed.

If this is something you're interested in doing — or just figuring out the optimal way to use your preferred beverage / gel / food of choice — that's why this app exists. I frequent the Triathlon Forum here on slowtwitch and am happy to answer questions.

Conclusions

Ironman has moved from a fuel source that does it all – mostly kind of okay, even if I have a worse taste in my mouth for Gatorade than I do Mortal… no pun intended – to a hydration beverage that requires people to either do one of two things: (1) stuff their pockets full of everything they can get their hands on at each aid station, or (2) purchase high-carb gels, chews, bars, or other portable single serve options (“sachets”). Be prepared.

The post Fueling IM Events in 2024 in a Mortal Hydration World first appeared on Slowtwitch News.

Amidst the marathon journey of distilling the complexities of nutrition in endurance sports to the most actionable advice, our focus today sharpens on a seemingly innocuous ingredient with a potentially profound impact: Stevia. As a natural sweetener derived from the leaves of the Stevia rebaudiana plant, it offers the allure of guilt-free sweetness, free from calories. (Guilt-free, if you assign guilt to calories… which you shouldn’t.) This characteristic has propelled it into the limelight, especially among health-conscious circles. However, the terrain of endurance sports is fraught with unique nutritional demands, where the difference between triumph and tribulation on the side of the road can hinge on the details of an athlete’s fueling strategy and its chemical composition.

The question then arises: In the grueling world of endurance sports, does Stevia play the role of a friend or foe?

It's crucial to recognize that the challenges outlined here, associated with Stevia, are not exclusive to this natural sweetener alone. In fact, most nonnutritive sweeteners present in endurance beverages can lead to similar predicaments, creating a facade of energy intake without the substantive caloric support necessary for sustained performance. This is why I usually advocate against the inclusion of any artificial sweeteners in products intended for use during training and racing. The essence of endurance nutrition lies in the provision of real, substantive fuel to meet the body's demands, not in the illusion of sustenance without the caloric and carbohydrate backing.

From a biochemical standpoint, the body processes steviol glycosides differently than other carbohydrates. When ingested, steviol glycosides are not broken down into glucose in the digestive system, which means they do not provide calories or affect blood glucose levels in the same way as sucrose or other nutritive sweeteners. Instead, steviol glycosides are metabolized by bacteria in the large intestine into steviol, which is then absorbed into the bloodstream and eventually excreted in the urine, having provided next-to-zero energy to the consumer.

The Sweet Illusion: Stevia’s Impact on Perception and Performance

Within the realm of endurance sports—marathons, triathlons, ultrarunning—athletes embark on a taxing journey, pushing their bodies to the limits of endurance and performance. In this context, carbohydrates are not mere nutrients; they are the very lifeblood of sustained energy. When athletes sip on their sports beverages, each gulp is a calculated intake of fuel, meticulously planned to replenish the body and stave off the specters of fatigue and depletion.

Enter Stevia, with its seductive promise of sweetness without the caloric cost. At first glance, it seems like a panacea for athletes wary of excessive sugar intake. Yet, herein lies the paradox: the sweetness of Stevia may create a psychological mirage, leading athletes to believe they are ingesting more carbohydrates than they actually are. This misperception can skew fueling strategies, leaving athletes undernourished and under-fueled when they least can afford it.

Perhaps most dangerously, it’s in the earlier hours of an event where you can get away with consuming fewer carbohydrates, for the time being. And any artificially sweetened products may bait you into doing just that: under-consuming early. Given the gut limitations during endurance exercise, especially during dehydration or thermal stress, once you’re behind on carbs, you’re going to stay behind. You’ve left performance on the table.

The Carbohydrate Conundrum and Cramping Catastrophes

As the miles stretch on, the body’s cry for carbohydrates grows louder. These are the moments that test an athlete's preparation and endurance. However, if the body is deceived by the sweetness of Stevia, believing it to be a sign of ample carbohydrate consumption, the reality can be harsh and unforgiving. The shortfall in energy availability not only precipitates a decline in performance but also plays a notorious role in the dreaded phenomenon of muscle cramping. Though cramps aren’t the bane of every athlete's existence, they serve as a stark reminder of the body's intricate balance of electrolytes, energy availability, and work capacity – a balance easily disrupted in the absence of sufficient carbohydrate intake.

In the absence of adequate carbohydrates, the body, in its relentless quest for energy, turns to fat as an alternative fuel source. While fat is a more than capable energy reserve for its sheer amount, its utilization marks a shift in physiological efficiency. The metabolic machinery required to convert fat to fuel operates at a slower pace, demanding more oxygen and elevating the heart rate for a given workload. This shift not only diminishes performance but also amplifies the perception of effort, making each step feel laborious, each pedal stroke a monumental task.

This metabolic inefficiency will be worsened if someone is accustomed to consuming carbohydrate fuel in high quantities and then makes a switch in training or on race day, to a nonnutritive sweetener like Stevia.

The Hypoglycemia Fest: A Sweetener’s Subtle Havoc

The reliance on Stevia-sweetened beverages, with their low carbohydrate content, sets the stage for a physiological predicament. As athletes press on, their bodies' glycogen reserves dwindle, and the absence of incoming carbohydrates from their beverages leaves a void. The result is a perilous slide into hypoglycemia, a state where blood sugar levels plummet as muscles vacuum up all remaining blood glucose, bringing with it a cascade of symptoms—dizziness, weakness, confusion, and an overwhelming sense of fatigue. While neurogenic hypoglycemia doesn’t necessitate large drops in physical performance – read: you can actually perform very close to optimally with low blood sugar for a while – the most prominent effect is on your psychology and your willingness to suffer. Both of which you need as strong as ever during your hardest training sessions and races.

An example: imagine a marathoner, miles into a race, steadfastly relying on a Stevia-sweetened beverage as her primary source of hydration and fuel. Initially, the beverage's sweetness provides a comforting assurance of energy replenishment. However, as the miles tick by, her pace begins to falter; her muscles, once responsive and vigorous, now twitch with the early warnings of cramps. The psychological toll mounts as she realizes her energy stores are depleting far quicker than anticipated, her beverage providing none of the promised sustenance.

Desperately, her body shifts gears, tapping into fat reserves—a process far less efficient and far more demanding. Her heart pounds against her chest, each beat a reminder of the increasing effort required to maintain pace. The marathoner's thoughts grow foggy, her limbs heavy, as the first tendrils of hypoglycemia take hold. In this moment, the allure of Stevia's calorie-free sweetness reveals its true cost: a compromised performance and a battle not just against the clock, but against her own body, lacking the basic substrate for maximizing performance.

Navigating the Nutrition Maze: A Path Forward

For endurance athletes, the journey to optimal performance is paved with meticulous planning and an intimate understanding of their body's needs. The science of fueling for endurance is not just about avoiding the negative but proactively harnessing the positive—choosing beverages and fuel sources that provide the necessary carbohydrates, electrolytes, and hydration to sustain effort over hours of exertion. The focus should be on real, tangible energy sources that can be readily absorbed and utilized by the body, ensuring that the athlete can maintain pace, power, and endurance from start to finish.

The role of beverages, then, is not just to hydrate but to fuel—to provide a steady stream of energy that can sustain the athlete through the rigors of competition and training. Stevia's main problem is the lack of carbohydrate-based energy. That said, the potential side effects from Stevia absorption — nausea, vomiting, GI distress — are unlikely to be felt by most athletes as the amount of Stevia consumed during exercise is relatively small. For some folks, however, Stevia sensitivity is the real deal. If you know, you know. And, if you don’t know, you don’t want to know.

A Detailed Note on Fuel Consumption and Stevia Sweetness Interplay

You may have heard – endurance athletes need a specific mix of glucose to fructose, ideally in a ratio between 2:1 and 1:1 – to fuel their performance effectively. This requirement is crucial for optimal energy absorption and usage during long activities, especially when carb consumption rates exceed 60 grams per hour, but a mixed composition is almost always useful. If you’ve tried this composition, especially closer to 1:1 glucose:fructose, then you’ve also noticed that it is a rather sweet mix, even if the flavor intensity is kept low.

Ideally, for a less sweet taste, one might lean towards using only maltodextrin or HBCD, as these glucose sources are less sweet. However, this approach doesn't meet the necessary glucose:fructose ratio. To achieve this balance, it's essential to include a significant amount of fructose or primarily use sucrose, which naturally contains glucose and fructose in a near-perfect ratio for endurance needs. Both fructose and sucrose are moderately sweet and can be consumed in the needed concentrations without overwhelming sweetness.

The introduction of Stevia, while beneficial for reducing calorie content, complicates this delicate balance. Stevia's intense sweetness can make the overall drink mix much sweeter than desired. This is problematic because, to adhere to the glucose:fructose ratio without making the beverage overly sweet, the formulation relies on the natural sweetness of fructose and sucrose. Adding Stevia pushes the sweetness beyond the tolerable threshold, undermining the goal of creating a less sweet, yet energetically balanced, endurance beverage.

Conclusion

While Stevia and other nonnutritive sweeteners may offer advantages in certain dietary contexts, their role in the nutrition strategy of an endurance athlete should be carefully scrutinized. The addition of the necessary carbohydrates to the consumption strategy of the athlete is likely to over-sweeten the milieu, in the presence of stevia. The foundation of endurance nutrition is built on the provision of adequate energy—a task for which calorie-free sweeteners are ill-suited. The addition of anything extra to a mixture is also a recipe for increased gastrointestinal tract distress symptoms, which can be show-stopping during training and racing. As we chart our course through the world of sports nutrition, let us be guided by the principles of science, the lessons of experience, and the unwavering goal of supporting the performance and health of athletes at every level, rather than by sweetening up our beverages to suit flavor and sweetness preferences of humans at rest. If you’d like to sip on stevia-sweetened tea in the evening before bed as part of your healthy sleep hygiene routine, by all means. But I’d recommend minimizing it during training and racing.

Dr. Alex Harrison is the founder of Saturday, an app to assist endurance athletes with their fueling needs.

The post Stevia in Sports Nutrition first appeared on Slowtwitch News.

Triathlon nutrition is essential for athletes, especially for those participating in a 70.3 race for the first time. Proper fueling can make the difference between a successful race and one marred by fatigue, cramps, or gastrointestinal distress. Nutrition is too often a black box that folks don't want to admit is an area of concern. This comprehensive guide will help you understand how to optimize your nutrition for your first 70.3 race, covering essential elements like products, water, amounts, and timing. It's time to eliminate the uncertainty.

On Carb Loading

More experienced folks can go above and beyond what is discussed here, but here are the basics for a safe carb loading procedure. You’ll get most of the benefits with virtually none of the risks.

3 Days Out: Add 100-150g carbs to whatever your typical diet would have looked like for that day of training. If you’re resting, maybe that’s 300-400g carbs. If you’re training, maybe it’s 400-600g carbs, total. Consume most of the extra carbs before 6pm so that it doesn’t disturb sleep.

2 Days Out: Add 150-250g carbs to whatever your typical diet would have looked like for the slated training. Maybe it’s 350-450g carbs total on a rest day, or 400-600g on a lighter training day.

Day Before: Add about 100-150g carbs to what is likely to be a limited training day or a light shake out. Maybe that’s 300-400g carbs.

Here’s an example for a 150 pound athlete who is doing about an hour of easy training each day leading up to their race day:

3 days out, 20 minutes swimming, 40 minutes running, all easy, 450g carbs consumed, with at least 400g consumed before 6pm.

2 days out, 60 minutes easy riding, 550g carbs with at least 450g consumed by 6pm.

Day before, rest day, 400g carbs,

If normal protein intake daily is ~130g per day, consider reducing it to ~100g per day during the carb load. If normal fat intake daily is ~90g per day, consider reducing it to 50-60 grams per day. If normal fiber intake is ~30g per day, consider keeping it there or reducing it very modestly. Just don’t chow down a high volume of fiber-rich carbs and you’ll be okay. For the duration of the carb load, stick with foods that your body is familiar with recently.

Remember, exact quantification of this stuff is highly unnecessary. If you want to get more granular about weighing out grams of nutrition, then the intra-race and intra-training fueling is a much better place to spend that time and energy. Still probably not entirely necessary, but much more useful than fussing over the specifics of daily nutrition totals or carb loading. There are time and psychology tradeoffs always. Consider wisely.

Race Day Breakfast

Target eating breakfast around 2-2.5 hours before swim warm-up starts.
Consume a meal with moderate to low protein, lower fat, limited to no fiber, very high carbs, and higher sodium. Caffeine if you like. Fluid can come from coffee, electrolyte beverage or juice. Don’t let sodium drop below 1000mg/L, total including all fluids consumed.

Example food choices: Cup of quick oats with skim milk, half cup of brown sugar, ?-¼ tsp salt. Coffee with milk and sugar to taste. Cup of apple juice or better yet, an electrolyte beverage with 1000mg sodium per liter of beverage. Up to a liter of water with breakfast.

The numbers: That might add up to 100-150g carbs, 10-20g protein, 0-10g fat, 0-5g fiber, 32oz of fluid, 1000mg sodium.

Pre-Race Hydration

Drink another 16-32oz between breakfast and racing, but don’t force it. Target 1000-2000mg sodium per liter (or per 32oz if we’re keeping the math easy). It’s okay to have another 10-20g carbs in this electrolyte beverage. Sugar & salt are great here. So are most dissolvable electrolyte tablets or hydration mixes.

If you are a first-timer and want to finish your 70.3 race safely and effectively, consider the following fueling plan. Keep in mind that this plan is based on general assumptions and may need to be adjusted according to your individual needs. I’ll lay out the safest option for the folks who are just here to finish, and an “optimal” option if you’re someone who’s more performance-focused.

Immediate Pre-Race Priming: Once you’re in your wetsuit, drink 8-24oz depending on thirst. Target 1000mg-1500mg/L sodium. 25g carbs. A gel, or sugar + salt + any flavored beverage you like will work great here. Get in the water. Get water in your suit. Do your swim warm up, if that’s allowed, and then finish any of the remaining beverage + gel combo.

Optimal Pre-Race Priming: Once you’re in your wetsuit, drink 16-24oz depending on thirst. Target 1200mg-1800mg/L sodium. 25-50g carbs. A gel or two, or sugar + salt or sodium citrate + any flavored beverage you like will work great here. Do your swim warm up, if that’s allowed, and then finish any of the remaining beverage + gel combo.

Race Fueling

Don’t waste time, or risk GI upset, by consuming anything in T1. Swim your swim, make it through transition, get on the bike with your shoes on, and your feet secure in the pedals, and get up to cruising speed. Now you’re ready for on-the-bike fueling.

On The Bike Fueling
The big three puzzle pieces you’ll notice throughout this article, are carbs, sodium, and water. It’s no different on the bike, and the bike is your time to shine when it comes to your fuel plan execution. Here are your options.

Safest Possible: Target 60-75g per hour. The reason not to do less, is if you underfuel, cramping, bonking, and fatigue and pace issues could prevent you from finishing. The reason not to do more is, if you’re inexperienced, and you mismanage your hydration, pushing carb intake rates up near or above 100g carbs per hour is more likely to cause debilitating gut issues, followed by an inability to fuel, and an inability to absorb the fuel, followed by bonking, cramping, fatigue, and pace issues. So, the 60-75g/hr range is a goldilocks optimization for this question: “what’s the most likely for all people, under all circumstances to get them across the finish line successfully?”

That same approach gives us a recommendation of about 1000 mg of sodium per liter of water consumed.

The hard part is knowing how much you’ll need to drink. If you’re small, a light sweater, and relatively fit, and it’s cool out, you might only need 400-500mL water per hour. If you’re larger, a heavier sweater, relatively unfit, or it’s warm or even hot or humid out, or all of the above, you’re going to need much more. Listen to your thirst and know that some folks do tolerate 1-1.5 L per hour of fluid on the bike. The key is to make sure your sodium intake per liter doesn’t fall.

Optimal: The major difference in the optimal performance nutrition and the safest-possible performance nutrition is carbohydrate intake. Most folks perform at their best using 90-130 grams of carbs per hour on the bike. Some very fit, and very experienced folks can benefit from as much as 150-160g per hour. Optimal for most first-timers with some time to practice their fueling, probably falls between 90-110g/hr on the bike.

The sodium and water story is just the same as the safest possible scenario. But you can push your upper limits of sodium consumption a bit more in hotter scenarios. So maybe in a cool, fit, small person it might look like 500 mL per hour with 500 mg sodium (because that’s what gives them 1000mg/L). In a hotter environment it might be ~2000mg of sodium in 1.5L water per hour, for a sodium concentration of 1333mg/L. Sodium concentrations of 1200-1800mg/L are sometimes tolerated, especially when using sodium citrate for at least half of the sodium consumed.

Run Fueling
Most folks experience some degree of dehydration on the bike, and they carry that dehydration with them onto the run. Pair that with the increase in jostling that the gut gets when you start running, and the gut tolerance for most triathletes goes down on the run, compared to the bike leg. Roughly a 20% decrease in consumption capacity is typical, but some folks can consume at almost identical hourly rates from cycling to running.

Safest Possible: To stay on the safe side, dropping fuel (carbs) intake rate from 60-75g/hr on the bike to 50-60g/hr on the run is a good idea. Consider still targeting 1000mg/L sodium on the run.

Keep in mind that your fluid intake may need to increase when you start running. There is less convective (air) cooling while you run, and in a 70.3, it’s also usually the hottest part of the race. Safe run intakes might look like 50g carbs per hour, 700mg sodium per hour and an increase in fluid intake rate from 500mL/hr to 700mL/hr.

For a 2-hour half marathon, that adds up to 100g carbs, 1400mg sodium, and 1400mL water (~48oz). The cups at most races have about 5 ounces in them.

Optimal: Even for seasoned athletes, optimal run carbs in a first-time 70.3 might drop to 70-100g/hr. Sodium should definitely stay at 1000mg/L or higher. 1500mg/L as long as sodium citrate is being used can be great too. If you’re “living off the course” usually the products on course do not use sodium citrate. Proceed with caution. Fluid intake on the run should seek to prevent dehydration here, and could easily range from 500-1200mL per hour depending on the temperatures. It’s rare for folks to be able to consume more than ~1200mL/hr while running in a 70.3.

You’ll need to listen to your gut, at all times. If it starts complaining, carb intake rate needs to be the first thing to slow down. Consumption of fluid with sodium should persist, unless you’re in gut catastrophe mode. Usually that extreme level of GI distress can be prevented by listening to earlier cues, pacing appropriately, and thermally regulating oneself (water on head anyone!?).

Now that you are thoroughly schooled in how to make a plan, it would behoove you to know that there’s an app for that.

What Are My Risks & What Do I Do If They Happen?

Finally, we're all risk mitigators at heart. We like to know what could go wrong. What are the consequences of the games we're playing here. Because of that "What happens if…" is one of the most common questions folks will ask once they start really thinking about these fueling details. So, here are the things that happen, and that you need to know while you're starting out with any numbers-based plan.

Remember, any plan has to be a living, breathing, flexible agreement you're making with your body. And you have to be able to understand your body's language to even have that conversation. Understanding the "what happens if…" is a great place to start.

First the what to do:
Fluid intake should match or slightly exceed your thirst.
Sodium concentration in fluids should increase as fluid intake increases.
Carb intake should decrease if you don't properly manage fluid and sodium intake.

“What happens if I…?”
Here are the answers to the most common "What happens if I?" questions:
–Overconsumption of fluids without sodium can lead to hyponatremia.
–Overconsumption of sodium can cause gastrointestinal distress.
–Overconsumption of carbs can also lead to gastrointestinal issues.
–Underconsumption of fluids can cause cardiac drift, faintness, fatigue, and cramps.
–Underconsumption of sodium can result in frequent urination, fatigue, swelling, and hyponatremia.
–Underconsumption of carbs can lead to fatigue, cramps, and a lack of mental focus.
–Gaps in carb consumption can cause faintness, hunger, hypoglycemia, and irritability.
–Gaps in sodium consumption are not a significant concern.
–Gaps in fluid consumption can result in stomach cramps, pain, nausea, and restricted carb intake.

Common Fueling Problems for Newbies
First-time triathletes often face these fueling challenges and end up wondering how it all went wrong. If you're in the learning stages of your nutrition journey in triathlon, keep these top of mind.

Forgetting to drink, leading to dehydration and hypoglycemia, followed by overeating and gastrointestinal pain.
Solution: consume steadily, early and often.

Not fueling adequately on the bike, resulting in a poor performance during the run.
Solution: consume steadily, early and often.

Choosing high-glucose supplements that cause gastrointestinal distress despite moderate carb consumption.
Solution: use mostly sucrose or 50-50 maltodextrin:fructose

Underconsuming sodium, leading to unsatisfied thirst and a sloshy feeling in the stomach.
Solution: put sodium in all beverages. Table salt or sodium citrate.

Relying on poorly formulated, well-marketed products that contain fat, fiber, protein, or sugar alcohols, which can negatively affect performance and cause gastrointestinal issues.
Solution: use mostly sucrose & salt or sodium citrate.

It’s time. You’ve read, you’ve learned, you’ve planned, you’ve trained, and you’ve studied the contingency plans. Go execute your plan (and plan B C & D, as needed) You now have the seasoned knowledge usually acquired through years of sometimes-anguish-filled learnings. I look forward to hearing how it went.

Dr. Alex Harrison & Michelle Howe, a pro triathlete, registered dietitian (RD) and board certified specialist in sports dietetics (CSSD), have come together with a growing team of designers and developers to create an app which quickly and easily builds professional grade fueling plans for your next 70.3.

The post A Comprehensive 70.3 Fueling Guide for First-Timers first appeared on Slowtwitch News.

Many fitness enthusiasts and health-conscious individuals often wonder whether consuming sugar during exercise is harmful. For some folks, it can be harmful immediately. For most folks, the harm it might cause is a long-term drift. The drift is a slow shifting of how organs operate, all moving towards blood sugar dysregulation, inflammation, or a chronic diseased state. It’s a slow process over the course of months, years, or even decades. Usually, it’s the kind of insidious slow worsening of your health that you only notice once it’s way too late to fully repair the damage. Permanent damage has been done. That sort of thing is worth understanding, and worth understanding really well.

Imagine a scenario where your body stops working normally. Cortisol is through the roof. Your gut isn’t functioning normally. It’s stopped absorbing things comfortably. Your skin is flush. You are breathing audibly louder than normal, and you’re sweating profusely. To get enough to eat, you have to nibble on things all day, because your gut can’t otherwise keep up with your energy expenditure and you’ll starve to death. You’re losing so much water and electrolytes through glands in your skin that you have to be constantly replacing it or risk severe dehydration and death.

Exercise is like no other time, for every organ in your body. Your body and its organs all behave differently during exercise than when you are not exercising. No other activity you do besides physical exercise causes such a dramatic temporary shift in the way every tissue in your body functions.

This article will delve into the topic, exploring the body's mechanisms that come into play during the one specific scenario which tends to change everything about how the body works. It’s a scenario where organs function differently than at any other time in the human experience.

It’s important to push back on ideas that have negative health implications for some people. In this article I’ll explore the relationship between health and sugar consumption during exercise. I will also examine the science of physical activity and how sugar consumption may, in fact, be beneficial rather than harmful. Not just beneficial to performance, but also beneficial to your health. If consuming sugar during exercise can be health-promoting, then the notion that consuming sugar during exercise is universally harmful is not only an oversimplification, but also harmful to many folks’ health.

The Role of GLUT4
To understand the impact of sugar consumption during exercise, it is essential to discuss the role of GLUT4, a transport protein found in muscles and the liver. GLUT4 is mainly dormant in muscles but becomes highly active, or "upregulated," during exercise. Its primary function is to facilitate the transfer of glucose from the bloodstream into working muscles, providing the necessary energy for physical activity.

During exercise, GLUT4 in the liver remains relatively inactive, allowing muscle cells to absorb the available blood sugar. This mechanism ensures that any sugar consumed within reasonable limits is utilized by the muscles, preventing blood sugar fluctuations and inflammation.

The Pancreas and Insulin Production
A key concern regarding high sugar consumption is the potential for long-term pancreatic damage due to increased insulin production. However, during exercise, sugar is absorbed into the muscles more efficiently and rapidly, with much lower blood insulin levels. This means that the pancreas doesn't need to produce nearly as much insulin, reducing the risk of long-term pancreatic damage.

Body Composition and Glycogen Storage
Paradoxically, consuming sugar during and immediately after exercise may actually improve body composition. This is because storing muscle glycogen (the storage form of carbohydrates) in muscles is a fat-burning process. Your body burns fat, to accomplish the physical storage of glycogen. Something has to provide the energy for stringing all the glucose molecules together in muscle cells and that ‘something,’ is fat. So, when you store up glycogen, it’s a fat-burning process. To add to all the good news around glycogen storage, muscles stocked with glycogen tend to build more muscle proteins at rest, which further promotes fat burning and blood sugar reduction.

Performance Enhancement
Ingesting sugar during exercise can also enhance athletic performance, particularly in endurance sports. Consuming carbohydrates in the form of sugar provides a quick energy source, helping to maintain blood glucose levels during prolonged activities. This can help delay fatigue and improve overall performance.

The Meandering Path to Understanding Sugar's Role in Exercise
While it may seem counterintuitive to consume sugar during exercise, a closer look at the body's mechanisms during physical activity reveals a fascinating interplay between sugar, muscles, and the pancreas.

Exercise triggers a series of complex physiological processes that allow the body to adapt and optimize its performance. In this context, sugar consumption can play a vital role in providing the necessary fuel for muscles, ensuring efficient energy utilization and promoting overall well-being.

The Road Less Traveled: Shifting Perceptions on Sugar and Exercise
As we navigate the meandering paths of health and fitness, it's crucial to keep an open mind and sometimes reassess our preconceived notions. The relationship between sugar and exercise is a perfect example of this. While conventional wisdom may dictate that sugar consumption is inherently bad, a deeper understanding of the body's response to exercise reveals a more nuanced and positive picture.

In fact, for many folks, learning to fuel appropriately can be so challenged by the misconception that sugar is unhealthy universally, that it presents a barrier to happily engaging with healthy fitness activities that they might otherwise come to love. It’s not uncommon for newer athletes and exercisers to report fatigue that can stop them from developing an enjoyable exercise habit. The absence of exercise in our lives today is an epidemic of unimaginable proportions. Paradoxically, convincing folks that sugar consumption is okay and even desirable during exercise actually promotes long-term exercise adherence and health.

Future Research Directions
As our understanding of the intricate relationship between sugar consumption and exercise continues to evolve, further research is needed to determine the optimal strategies for different populations and athletic pursuits. Investigating the long-term effects of sugar consumption during exercise and exploring alternative energy sources for athletes could provide valuable insights. Future research may pave the way for more personalized approaches to nutrition and fitness.

A Journey of Discovery
The exploration of sugar consumption during exercise highlights the importance of continually reevaluating our beliefs and understanding the nuances of health and fitness. By embracing a spirit of curiosity and a willingness to challenge conventional wisdom, we might gain improved well-being, enhanced performance, and maybe even have a deeper appreciation of the complexities of the human body during exercise.

While sugar consumption during exercise may have been perceived as harmful in the past, a closer examination of the body's physiological processes reveals that it can be beneficial in certain situations. By understanding these mechanisms and adjusting our approach to sugar intake during exercise, we can harness the advantages and avoid potential negative consequences. The key lies in finding the right balance and making informed decisions that best serve our individual needs and goals.

In Conclusion, A New Perspective on Sugar and Exercise
The notion that consuming sugar during exercise is universally harmful may not be just an oversimplification. It can be harmful to newer exercisers everywhere who could more easily be encouraged to develop exercise habits that they love. They might learn that consuming sugar during exercise would allow them to feel differently, and leave them feeling less fatigued and dysregulated for the rest of the day. By considering the activation of GLUT4, the reduced insulin production by the pancreas, and the benefits of glycogen storage, we can begin to appreciate that sugar consumption during exercise may not only be harmless but also be advantageous in certain circumstances.

As we continue to explore the intricate world of health and fitness, it's essential to approach topics with curiosity and a willingness to challenge prevailing beliefs. In doing so, we can uncover new insights, broaden our understanding, and ultimately, make more informed decisions about our well-being.

Selected Sources

The Role of GLUT4:
–Malin SK, Kirwan JP. Glucose metabolism and exercise: implications for diabetes prevention and treatment. Clin Nutr Res. 2014;3(2):89-96. doi:10.7762/cnr.2014.3.2.89
–Reusch JE, Begum N, Sussman KE, Draznin B. Regulation of GLUT-4 phosphorylation by intracellular calcium in adipocytes. Endocrinology. 1991;129(6):3269-3273. doi:10.1210/endo-129-6-3269

The Pancreas and Insulin Production:
–Karlsson HK, Zierath JR, Kane S. Insulin signaling during exercise. Exerc Sport Sci Rev. 2004;32(2):48-53. doi:10.1097/00003677-200404000-00002
–Colberg SR, Sigal RJ, Yardley JE, et al. Physical activity/exercise and diabetes: a position statement of the American Diabetes Association. Diabetes Care. 2016;39(11):2065-2079. doi:10.2337/dc16-1728

Body Composition and Glycogen Storage:
–Ivy JL, Katz AL, Cutler CL, Sherman WM, Coyle EF. Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion. J Appl Physiol. 1988;64(4):1480-1485. doi:10.1152/jappl.1988.64.4.1480
–Volek JS, Kraemer WJ, Bush JA, Incledon T, Boetes M. Testosterone and cortisol in relationship to dietary nutrients and resistance exercise. J Appl Physiol. 1997;82(1):49-54. doi:10.1152/jappl.1997.82.1.49

Performance Enhancement:
–Burke LM, Hawley JA, Wong SH, Jeukendrup AE. Carbohydrates for training and competition. J Sports Sci. 2011;29 Suppl 1(Suppl 1):S17-S27. doi:10.1080/02640414.2011.585473
–Currell K, Jeukendrup AE. Superior endurance performance with ingestion of multiple transportable carbohydrates. Med Sci Sports Exerc. 2008;40(2):275-281. doi:10.1249/mss.0b013e31815adf19

Hydration and Electrolyte Balance:
–Casa DJ, Armstrong LE, Hillman SK, et al. National Athletic Trainers' Association position statement: fluid replacement for athletes. J Athl Train. 2000;35(2):212-224.
–Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-390. doi:10.1249/mss.0b013e31802ca597

The post The Risks, Harms, and Science of Sugar and Endurance Athletes first appeared on Slowtwitch News.

For years, we have believed that ninety grams per hour is a seemingly mythical upper limit to safe and useful carb consumption in triathlon and any other sport that’s crazy enough to suffer for three, four, or twelve hours. There have always been whisperings that maybe it’s the limit, but they slip through the cracks and don’t lodge themselves in our memories.

The concern most of us share about consuming too much carbohydrate in training is that it will mess with our gut, so we aim lower to be on the safe side. It’s a delicate balance of avoiding the portaloo while keeping blood sugar elevated enough to enhance performance. Balancing GI issues, and not bonking. It has been treated as sacrosanct that if you do manage to consume 90 grams per hour, your only risk is gut discomfort, and certainly not hypoglycemia and bonking.

But take a man whose profession it is to sprint for 5 seconds, twice a day, while pushing a 600 pound sled, and seat him on a 15-year-old entry-level Trek road bike for six and half hours. The result of putting a gorilla of a bobsledder on an old bike for his first century ride in 15 years? New levels of hypoglycemia and hunger, even with industry shattering high carbohydrate consumption rates. He was able to avoid GI distress and still managed ongoing hypoglycemia while consuming 117 grams of carbs per hour, even though his record-low aerobic fitness provided him little capacity to burn energy

Without any gut training, those carbohydrate consumption rates were a powerful neutralizer to the industry dogma that 90 grams per hour was a nearly mythical ideal that works for everyone doing endurance sports. A disastrously unfit person with no gut training managed to achieve hypoglycemia and no gut issues with 117 grams of carbs per hour. Either he happened to be a bizarre double-outlier in his ability to burn carbs with no aerobic fitness and to avoid GI distress at absurd fueling rates, or there must be some holes in the literature.

This spawned a deep dive into the literature for the benefit of us all. I had to know. And this deep dive into decades of fuel and hydration research was with relatively fresh eyes, since I’d been mostly uninterested up to that point in my academic career.

Those fresh eyes were also highly motivated to understand all the factors at play. The bobsledder was me and this is my story.

Years of anaerobic training came with a humongous ability to burn carbohydrate and virtually no fat oxidation ability. Friendly reminder: “oxidation” means burning the stuff as fuel for your body’s energy output. I had no fitness, and thus virtually no capacity above resting metabolic rate to use fat as fuel. Whether you’re in the keto camp or the high carb zealot camp, or somewhere between, it’s generally agreed upon that high fat oxidation ability is a key performance indicator for endurance sports.
The ability to burn fuel aerobically is key for endurance sports, and I’d trained and “sedentary’d” my aerobic fitness away long ago, as most bobsledders do. In case you’re not familiar, being intentionally sedentary outside of training is performance enhancing in speed-strength sports like bobsled. It also takes aerobic fitness to all-time lows.

I was coming off an almost four year post-decathlon stint as a professional bobsledder. I was 6’1”, 225 pounds and 10% body fat. I squatted nearly 500 pounds and snatched almost 300. That’s the one where the barbell goes floor to overhead in one swoop. I bench pressed 400 pounds.

I looked like it. And most of all, when I was on that Trek, I felt like it.

I had broken my foot 6 months before the 2018 Winter Olympics and went from being an Olympic hopeful in bobsled and idle bystander in Michelle Howe’s triathlon & cycling pursuits, to trying dearly to hold her wheel, overnight. Cycling was the past love that I immediately rekindled upon retiring from professional speed and power sports.

I knew from past exploits a decade earlier (on the same Trek 1200), if I rode that century, I was going to be hungry. I thought I knew from preliminary research that 90 grams was the upper limit for most folks. But I was desperate and knew that this century was going to be as much of an eating contest as it was a pedaling contest. So I packed what I thought would be overkill. More than possible to consume.

I finished in 6 hours 30 minutes. It took all of me. I had roughly a 2.0 W/kg FTP at the time, and there was a 10% grade hill where I distinctly remember that my bike momentarily rolled backwards between a couple of my pedal strokes. My cadence was momentarily negative. Yikes.

For the fateful ride, I had planned to consume whatever my gut would allow. I did just that. And I was absolutely ravenous at many points during my ride and even more so at the end of the ride.

Here’s what was consumed:

~115 grams of carbs per hour
2 unaccounted for snickerdoodle cookies. Possibly other things.
800mg caffeine (see: bobsledder)
~7000mg sodium
Untold liters of water. I lost count by 40 miles in. I was already in a world of hurt. This was roughly 30 miles before the “did I just roll backwards?” moment on the hill.
~500 Calories per hour.

It was in the middle of that ride that I realized over and over that I wished I had carried more carbohydrate fuel with me. Hypoglycemia doesn’t even begin to cover my experience. The crash was real.

Counter to every major textbook and position stand by a major sports nutrition journal, I could have, and would have happily, used more fuel. By the time I finished my gut was absolutely empty. Achingly empty. Craving calories empty. I experienced no problems with gut clearance, gut cramps, feeling full, sloshy, nauseous, or burpy. I felt fine. Just ravenous and thirsty.

That said, for many folks, intimate personal experience with gut issues makes them leery of coming anywhere near these fuel intake rates.

However, it was during the ride that I realized that 90 grams per hour absolutely had to be hogwash as the upper limit of utility for a lot of folks, and it most certainly was hogwash in terms of gut tolerability.

I either had to have been an outlier of outliers in gut tolerance ability, or the research wasn’t as clear cut as it seemed.

The problem had to be an implementation and strategy problem, and I was dead set on figuring out what I’d done that had allowed such high intake rates in the face of a decade of convincing claims that nobody’s gut could tolerate more than 90 grams of carbs per hour. It turns out, there have been those kinds of anecdotes of high capacity to intake fuel since the 1980’s. They’ve largely been ignored by the scientific community. The herd mentality has been strong among my scientific peers.

I could have, and would have happily, consumed more fuel throughout the ride. I believe I’d have been able to go faster if I’d had it available. And I had exceeded the current day industry standard, increasing the upper limit of carb intake by 25 grams per hour, or almost 30%.

Sure, I was a special case in terms of carb oxidation. I was indeed an inefficient carb-burning gorilla. But my gut wasn’t special. Guts aren’t larger or more absorptive just because you bench press lots and eat pounds of protein every day. I had done no gut training. I hadn’t monitored my glucose:fructose ratio (something that is typically stated to be of critical importance when approaching even 90 grams per hour, let alone 120 grams per hour), and I had just used plain sugar. Almost 1 quart of plain sugar, mind you.

A whirlwind of a year later, I co-wrote a book on fueling and diet for nutrition athletes. It's a little out of date by my standards now, but by industry standards it’s still a decade ahead.

Together with my beloved contrarian wife, Michelle Howe, endurance coach and dietitian (who reads all my work, and pokes dozens of holes in my claims, my memory, and my stories, and is always right), I hope to negate the need for reading that book by giving you all the need-to-know and most up-to-date information on our YouTube channel and through articles like this one, and the many that follow. We’re working hard every day on an app that also does this all for you and coaches you to the right fuel.

Most importantly, during that year of reading and writing, while consulting a growing number of endurance athletes on their race fueling plans, I began to have a clearer view of the landscape of the endurance sport nutrition world.

Since that fateful year, my endurance fueling research has exceeded my doctoral research area in both professional experience and education, and Michelle can still argue me into the ground on virtually any fuel & hydration topic she chooses. That’s saying something, since I was a professional bobsledder, I built a bobsled training facility, and my 300-page doctoral dissertation was on how to push a bobsled faster. Michelle has gone pro in triathlon, placed top 5 in the country in the pro nationals time trial, and become a board certified specialist in sport dietetics. Suffice it to say, we’ve taken a few steps forward out of the fuel & hydration darkness from our days of riding our aluminum Trek’s with obnoxiously unlubricated chains.

We hope to bring our learnings to your world of fueling & hydration so that it’s a little more clear, accessible, and most of all, simpler and easier to do right. Especially when you’re just getting started. It shouldn’t be the black box that it was for me when I first made the switch to endurance sports. The research is clear. There should absolutely be some personal trial and error, but it shouldn’t be clouded in fear, doubt, and uncertainty.

The post Wrapping Up Our Sports Nutrition Series first appeared on Slowtwitch News.

If you’ve ever tried to figure out how much of what exactly you’re consuming when you consume FuelDrink SuperNova 2.0, you’re probably slightly on the nerdy side. But maybe wise, too. Turns out, sugar ratios matter, especially when you’re targeting a high-carb fueling approach. Get it wrong, and you might end up believing that carb consumption rates over about 60 grams per hour during endurance training or racing just aren’t for you.

It’s probably not the total intake rate that’s your problem.

Refresher: intake = consumption. Uptake = how much makes it from your gut to your bloodstream, and that’s what matters for performance.

So, let’s say you’ve learned that you ought to target a 2:1, or a 1:0.8, or a 1:1 ratio for your endurance fuel mix, and you want to evaluate a product. That product might not disclose their ratio on the package. Here’s how to do it.

First, check total carbs, then look at added sugars, then review the ingredients list. Remember that ingredients listed after another are never present in greater quantity than the ingredient listed before them. It’s also handy to remember that salts, flavorings, etc, are usually included at very low amounts, so if there are carb ingredients listed after those salt names, flavorings, preservatives, etc, they can pretty much be ignored.

Let’s walk through an example. Call it Product A.

Product A has 40 grams of carbs per serving. 30 grams of “added sugars” are listed in the nutrition facts.

The ingredients read as follows:

• organic non-GMO super-duper-natural cane sugar
• Maltodextrin
• salt
• dextrose
• sodium citrate
• natural flavors
• citric acid

How much glucose and fructose do we have? Good news! On this one we can figure it out, probably to within a gram.

Maltodextrin always counts as a non-sugar carb. Dextrose and sugar (sucrose), no matter how many fancy words they put before it, will always be considered an added sugar, as far as the nutrition label is concerned.

So, 40 minus 30 gives us 10 grams of carb that have to come from maltodextrin, because there are no other carb sources that would be counted as a non-sugar carb. The dextrose was listed after salt, and there’s never more than a gram of sodium in a serving of a product so it’s a safe assumption that there is less than a gram of dextrose in this product and we can just ignore it for simplicity.

That means the 30 grams of added sugars are all sucrose (AKA organic non-GMO super-duper-natural cane sugar)

So, we’ve got 10 grams maltodextrin, plus 30 grams sucrose. Sucrose is 50-50 glucose & fructose, for Product A are 15 grams of each. Maltodextrin is purely a glucose contributor, so that adds 10 more grams of glucose, on top of the 15 grams contributed by sucrose.

Our totals are now 25 grams of glucose and 15 grams of fructose. A 3:2 ratio. Not bad. Right between the 2:1 & 1:1 so probably could work as a primary carb source for most folks, most of the time.

If your head is spinning, you may like an upcoming feature of this app. It will eventually calculate glucose fructose ratios for you. For now, read labels carefully, and take solace in the fact that it does NOT need to be exact. You can get it a little wrong and still end up fine. The reason so many people believe it’s a huge and ongoing trial and error process is that they’re not starting with the science first. They’re intuiting their way to success, which may eventually get you there, but it’s a very roundabout and sometimes painful path. Following the science will certainly be less painful.

The post Deciphering Carb Nutrition Facts first appeared on Slowtwitch News.

Editor's Note: This title is in reference to myself, who has managed to mess up the below points in more races than I care to admit. My former coach labelled me "dazzlingly incompetent" for managing to self-sabotage a race that frequently; hence, a guide for us!

Here’s your crash course in things that you might want to consider adjusting, if you’re having issues while targeting higher carb intake rates during training or racing. There’s a lot to manage, but once you get it right, it becomes an intuitive process of listening to your body and responding in stride.

If You're Bonking

Consume more carbs. You’re underdosing carbs for how long you’re training.

If you’re getting shaky, irritable, or hungry

Consume more carbs! You may be hypoglycemic. Carbs are the antidote.

If You're Cramping

Consider more sodium, and more fluid, but never more of the latter in proportion to the former. Don’t dilute your electrolytes just because you need more water! And consider more carbs. Sometimes cramps are simply more fatigue-related than electrolyte related, and carbs are a powerful combatant to fatigue.

As a reminder, we covered off a lot of this here.

If You Feel Like You Can't Take More In

Use liquid carbs only. Eliminate solids. Especially things that aren’t gels and chews. But those can be trouble too, if you’re not dialed in on the rest yet. Just too high of a risk of hitting your gut with high carb concentration in a precarious state.

When In Doubt, Drink More

This matters for two reasons.

1. You need to stay hydrated for your gut to work properly.

2. Separate from being hydrated, you need to have water in your gut for carbs to absorb. Not consuming enough water with your high level of carbs is a recipe for guts revolting. The overall solution in your gut matters for both absorption and comfort. 100 grams of carbs per liter = 10% solution concentration. Most folks can tolerate 12-18% if they’re also well-hydrated. At the end of a race, maybe bump it down to 8-10%, more fluid needed! At the end of the day, fluid needs should be driven primarily based on hydration needs (how much you are sweating). If you manage that, and don’t have ridiculous instantaneous dumps of ultra-high-concentration stuff (gels & chews) into your gut, you’ll be fine on this front.

When In Doubt, More Salt

This matters for a dozen reasons, but here are three.

1. It’ll increase your thirst. See number 4, above.

2. Sodium helps carbs absorb in your gut.

3. It’ll help reduce urination (don’t worry, you won’t get the ocean water effect, and if you think you are, you’re not. You still need more salt. It would take tablespoons of sodium to get the ocean water diuresis effect.)

Manage the Glucose:Fructose Ratio

Target between 2:1 and 1:1. 1:1 is probably fine. Closer to 1:1 is probably better than 2:1. Sugar = 1:1. It’s one molecule of glucose:fructose. Maltodextrin & fructose, is gram for gram 1:1. It’s another way to get 1:1 glucose:fructose because maltodextrin is a pure glucose source. Here’s 60 seconds of slam dunk maltodextrin info:

No Other Carbs

Michelle (my wife) did a neat video on monosaccharides and what they mean for endurance athletes.

No time to watch? Don’t use galactose. Don’t use anything that doesn’t present just glucose and fructose.

Avoid Complex Carbs (Except Maltodextrin)

Not all complex carbs are created equal. First, a primer here: complex carbs are any carbohydrate that is composed of 3 or more monosaccharide units. (ie. single sugar molecules). Stick 3 of them or 20 of them together and you have a complex carb. Some “complex carbs” also known as “long chain” carbs. They are quite rapid to digest because breaking them down in your digestive tract is not a rate limiter for absorption to your bloodstream from the lining of your gut. It just happens so fast, that they are essentially the same as simple sugars, physiologically.

The advantage to using them is that they lower the osmolarity of the solution in your gut, which is a good thing when trying to let your gut do its thing during exercise. Too many molecules in solution is called a hyperosmolar solution. Stomachs and intestines don’t like that. But, they’re not as bothered by it as we once thought, so most of the “osmolarity” and “isotonicity” related marketing these days is just that: marketing.

That said, there absolutely are many complex carbs that do NOT sit well or digest quickly through your gut. For example, consuming waxy maize starch is just a recipe that hinders your ability to consume more per hour. “Slower to digest” is code for “going to cause GI issues if you consume at 80-130 grams per hour.”

So, if you’re concerned with maximizing performance and minimizing gut issue risk, stick with maltodextrin as your non-sugar carb source.

If You're Hungry

You're underfueled. More carbs are the solution.

If You're Having Stomach Issues

This is especially true if it is happening later in your training or racing. You're either:

1. Not consuming enough water with your carbs.

2. Mismanaging glucose:fructose ratio, usually too high on glucose for experienced or “old school” athletes.

3. Consuming disastrously too much sodium. (ie. you used a tablespoon, not teaspoon). Or:

4. Consuming too many carbs per hour for your hydration status or thermal stress. Usually this is caused by delays in fueling and hydration implementation earlier in the activity. Start earlier. Start fueling and intaking fluid with the first step or stroke (arm or pedal, you choose) next time.

If You're Confused By What's In a Product

Some handy definitions.

Dextrose = glucose.
Fructose = fructose.
HFCS = ~50:50 glucose:fructose
Maltodextrin = glucose.
Sucrose = 50:50 glucose:fructose
Maple syrup = 50:50 glucose:fructose, but with some other stuff in it.
Tapioca syrup = glucose
Honey = 3:4 glucose:fructose and math is hard. Avoid, unless using a product alongside it that you know is overdosing glucose.

For products containing maltodextrin as the only long-chain carb, plus other sugars, you can check the nutrition label and get a better handle on what’s actually being sold to you. First, check total carbs. Then look at added sugars. Then review the ingredients list. Use logical reasoning. Not sure how this works exactly? Stay tuned.

The post The Dazzlingly Incompetent’s Guide to Fueling first appeared on Slowtwitch News.

It can be a dangerous game to scale your hourly carbohydrate intake downwards during training. Even when scaling according to activity, duration, and intensity. It can lead to questions like “did I earn this fuel?” which is one of the slipperiest slopes in nutrition. However, it’s also probably a good idea to consider scaling your carb intake back a bit if you’re sometimes using very high-carb intakes.

Your intuition is probably telling you that you don’t always need to be gulping sugar-water, and your intuition is right.

First, before you can scale something back, you have to know what the upper end is, so you know where you’re even pulling back from. Then you need to know how much and when to scale things back. (That’s where the previous articles in this series come in.)

If you’re short on time, the summary is: there’s really good evidence that some folks, and not just elites, can benefit from using 100-140 grams of carbs per hour in training and racing. It might take gut training, but not much (if any), especially for the lower end of that range. What it does take is some skill in implementation.

I wish I could say that there have been books written on this. Unfortunately, the prevailing dogma, which has been confirmed in misguided practice by all of us for decades, is that nutrition is a black box that involves loads of trial and error, and that 90 grams per hour seems to be the upper limit of what’s useful and possible.

That’s simply not true. Thankfully the research industry and, with some effort by my wife and I, the app industry, are both catching up to what many athletes have known for more than a decade, via their own careful implementation and tracking. But, just because 120 grams per hour is the maximum for you (it might be higher) doesn’t make it optimal. Sometimes less is more. Let’s get into the real world for a minute.

Here are some good times to implement high-carb fueling:

1. Races over 3 hours.
2. Training sessions where effort is moderately high, that are>3 hours.
3. Training sessions>5 hours with anything but the easiest possible.
4. If you’re practicing race nutrition in preparation for a race. GI issues are caused far more often by poor implementation than by overconsumption.
5. If you’re training your gut to handle more carbs, even if effort is low, or for shorter duration activities.

So, that leaves the following scenarios where we’ve yet to figure out what to do, if we’re not going to be slamming>100g per hour carbohydrate:

1. Not gut training or practicing fuel implementation during lower-effort activities in the 3-5 hour range.
2. Higher effort activities shorter than 3 hours, while also not gut training or practicing fueling implementation.

I’ll assume that both those latter options comprise more than 50% of your training. If you’re knocking out higher effort 3 hour sessions more than 2 days a week, I’d hope you’ve already figured this out by now or you’re likely to have been having really spotty training quality. That being said, there is good reason to be practicing race fueling until you’ve got it down pat. And sometimes easier shorter sessions are nice to play with new things. Lower risk. Closer bathrooms. Fewer hours of suffering if it goes wrong.

For us mortals, we need to go beyond practicing higher intake rates. We should consider scaling back our carb intake rate ranges first by duration, and second by intensity, most especially for the lowest intensity workouts. But duration trumps intensity, always. For a good look at duration-based carb intake rates, and a more detailed explanation of what and how to consider, this is a good video, replete with a handy table for your reference at the end of the video.

Duration is the biggest driver of increased carb intake rates because you simply run out of endogenous carbs (carbs stored in your body) to burn. If you don’t have a high fuel rate, when those start to run out, blood sugar is going to drop. Performance follows blood sugar.

Even if you do fuel at a high rate, blood sugar may drop. But fueling even modestly is a recipe for feeling ever more fatigue during very long training sessions and races. To keep blood sugar optimal, very high-carb fueling, usually well in excess of 80 grams per hour, and often much more than 100 grams per hour, is necessary.

Intensity related fueling changes come into play most strongly when intensities are lowest. The difference in your internal carb oxidation (burn) rate between super low effort, and somewhat low effort, can be substantial. The reason the difference between the lower intensities matters more than those of higher intensities: you're burning almost exclusively carbohydrate whether you’re doing HIIT training or threshold work.

Put plainly, your carb needs are going to be based more on duration, purely, in those cases because there’s little difference in the carb vs fat utilization ratio. That is, you’re burning carbs, when you’re working hard. It just comes down to how long you burn them. It’s when your effort level drops well below threshold for the quality portions of your activity, that we can consider scaling carbs back. I might recommend a very very slight, or nonexistent reduction in rate, when stepping down from threshold to sub-threshold, higher end aerobic, “tempo,” or “sweet spot” training. Better to be well-fueled when operating at relatively high efforts.

Once down in the lower aerobic intensities, for those with good fitness, or long training history, there can be a pretty marked step down in necessary fueling rate with no meaningful difference in performance. Consider taking the biggest steps down in fueling rate for shorter activities and progressively smaller steps down in fuel rate for longer activities.

If you’re newer to endurance sport, or maybe a bit heavier, or less fit, (I am all three of these things) maybe take less of a carb rate reduction for low intensity work. You’re inefficient. Me too. It means we burn more carbs per hour and a greater relative proportion of our energy comes from carbs. Don’t try to increase your fat oxidation by cutting carbs either. Just accumulate training time, and you’ll get better at burning fat and carbs.

For virtually everyone, when intensity is pared back to “recovery,” ie. the very easiest training, fuel intake rates can often be cut in half, comfortably. For the shortest recovery activities, it sometimes makes sense to not fuel at all. For longer ones, one third of your max fueling rate might make sense.Stay tuned for an upcoming crash course. For now, keep your carb simple and limited to glucose and fructose. Limit or completely eliminate fat, fiber, and protein, from your fueling plan. Drink and salt more. Your gut will thank you.

Not sure how much salt? Here’s some quick help:

Consume plenty of carbs when they count, and less when they don’t.

The post Should You Scale Carb Intake Down on Easy Days? first appeared on Slowtwitch News.

Recent papers have displayed quite clearly that non-elite athletes can tolerate 120 grams of carbs per hour. Even older research has indicated that it might take consuming up to 140 or 150 grams of carbs per hour to absolutely maximize exogenous carb oxidation, during exercise. (Biochem refresher: exogenous means “from outside the body,” and oxidation means “burned to fuel the work done.”) There are countless anecdotes of pro athletes and regular folks consuming and benefiting from>100 grams of carb intake per hour during events lasting longer than 3 hours, and especially for events longer than 4 or 5 hours.

Does that mean you should target 100 grams of carbs per hour for every training session from now on?

For elites, probably not.

For high-level amateurs, also probably not.

For more “regular” amateurs like myself, absolutely not. Why not? Good question. Here's a few reasons.

It's Unnecessary

It doesn’t take 100 grams of carbs during a 60 minute recovery ride to get through the ride. Likewise, you don’t need two gels to get through a 30 minute aerobic run. For shorter and easier sessions, if you’re fueling with carbohydrates through normal consumption before training, high carb intakes during training are simply overkill.

Gut Training Doesn't Take That Long

In case you missed it, “gut training” means training your gut to handle more carbs without upset. It does work, but it’s probably more popular than it is useful. It’s usually done before a race.

You might be seeking improved gut tolerance of carb intake for an upcoming race. Interestingly, gut training doesn’t take years to complete. You can probably reap most of the benefits of gut training in under 6 weeks. Maybe much less than that. It appears from research that there could be substantial adaptations within two weeks. So, if you’re considering using higher carbs to train your gut, keep in mind that it doesn’t need to happen all year long.

Race Fueling Practice Doesn't Mean Every Session

You may have heard “nothing new on race day.” That’s safe and mostly-good advice. So you want to work on your race fuel plan. You can start with shorter rides and work upwards in length. Or start with longer, easier rides and just work on those. If you’re struggling to make your race fuel plan perform well on longer activities, nail it for shorter ones first. Then, implement it on the longer ones. Once you start practicing race fueling on the long days, you can begin scaling carbs back downwards to a more necessity driven and reasonable level for shorter training sessions.

Quick sidebar here: For those of you with even a super-subtle tendency towards periodically restrictive eating habits, this should NOT be read as “make sure to limit your carbs when you don’t feel like you absolutely need them.” Instead, if you’ve ever struggled with disordered eating, or just chronically feel like restricting calories, it’s better to target over-fueling training a bit. It never hurts to consult a professional for an outside take on what might be optimal. Intuition will hopefully be a good guide for you in the future, but it can be a bit misleading if that negative internal voice is compelling you to short yourself your needed energy.

You should feel genuinely great during training. If you’re not, you should consume more carbohydrate, now, and earlier in training in the future. And maybe consider skipping the rest of this article and watching this instead.

Potential for Weight Gain

You’ll likely need to eat a bit less outside of training if you jump from 60 grams per hour to 120 grams per hour. If you double carb intake in all your training, all the time, you’ll have to make substantial cuts to the food eaten outside of training. That may mean lower nutrient density of your diet overall.

Blood Sugar Dysregulation

This is a distant concern for those who’ve never struggled with their body weight. But, if you’ve carried 30 or more pounds than you currently do, and most of that was fat tissue, (ie. not muscle) at any point in your life, that’s another feather in the cap of “probably shouldn’t max out fueling rates all the time.” The reason is: blood sugar dysregulation remains more likely later in life after substantial weight loss than it would for a person who had never carried more fat tissue. Even if you have existing blood sugar regulation issues, or currently are at risk, a scaled back approach is perfectly safe and healthy. It looks like this: fuel the harder or longer sessions more aggressively, but fuel on an as-needed basis for your recovery and basic aerobic workout.

Hunger

Some people just get hungry outside of training and would like to have some more room in their diet for food outside of training. That’s definitely my personal preference. I just like to eat. Food tastes good. So I usually fuel minimally on my very short runs, and recovery rides up to 90 minutes or so. I don’t underfuel and I recommend you not do that either, because doing so is a recipe for hypoglycemia, which is a recipe for eating everything in the fridge when you get home. Kind of defeats the purpose, so listen to your body. Learn to know the signs of hypoglycemia and learn how much and when to scale back your carb intake when you think it’s appropriate. It’s a balance.

Quality of life matters. You can manipulate your fueling strategy to accommodate things that bring you higher quality of life. And you should. Joy is important in endurance training. If you don’t have joy in training, you won’t last long enough in endurance sports to reach anywhere near your potential.

I posit that it’s high time for a more individualized approach to carbohydrate intake. It should be individual to you and all your personal considerations. Individualized by session details. And someone should show you how to understand it. And I hope it doesn’t come tagged with the word “periodized” attached to it. Periodized is an entirely different meaning and can almost now be defined as “something someone really wants you to buy, related to training or nutrition” Shame on the industry, myself included, for taking so long to explain how to scale carbs according to your effort and duration, and your individual needs.

The post Should You Use a High-Carb Fueling Plan All the Time? first appeared on Slowtwitch News.

Is a high-carb fueling approach needed during all your training sessions? First maybe let’s get on the same page about what a high-carb approach might be. This debate about what to consume during training has raged on for decades. In 2010, we heard about 90 grams per hour. Or maybe it took a few more years for that information to leak its way off of landmark journal review articles and position stands on Slowtwitch’s forum, and out to your eyes and ears.

Flash forward a decade. Here’s a study examining ultra-marathoners using 120 grams per hour. Result: reduced muscle damage. Here’s one with increased exogenous carb usage comparing 120 grams per hour to 90 grams per hour. And here’s another paper finding that there isn’t (much) difference between tolerability of intake methods using 120 grams per hour.

Reminder: intake = consumption. Intake methods compared in the paper were gels, chews, liquid-only, and a mix of all three. Whether there is a difference or not, remains to be seen. While these papers mostly look at 2-3 hours duration activity, that’s predominantly due to research data collection challenges. Extending research exercise periods out beyond 3 hours becomes imposing on researchers and subjects, especially when you figure in familiarization sessions, control trials, sham or placebo trials, multiple test conditions, etc.

It’s not just papers from 2022 that indicate possible benefits from>100 grams of carbs per hour in training and racing. In case you don’t want to take my word for it, here’s a detailed review from 2017. And here’s a few studies finding relative tolerability before much was publicly known about glucose-fructose coingestion: all from before 2007.

So why only 10 years ago did we hear about 90g/hr? And why only now do we hear about 120g/hr? And only at a whisper level? That’s a story for another time. Try not to put your tinfoil hat on, and I’ll keep mine on the shelf for now, too.

What about women? All those papers only examined high carb intakes in men. And that matters. Women are indeed, not small men. Thank you to Dr. Stacy Sims, for pioneering & championing that phrase, which I’ll happily borrow. Dr. Sims, you are spot-on, and if you ever read this, please know I’m grateful for your contributions to this field. They’ve been nothing short of invaluable.

Thankfully, it’s not just men that appear to benefit from high carb intakes. While the research has been sparse in women, I’d posit that has more to do with sport and research culture and bias, than on gut or muscle physiology.

Beyond my wife Michelle, who, a competitive triathlete & cyclist at 138 pounds, routinely implements 110-130 grams per hour on her 5-hour trainer rides, or 90-100 grams per hour on her 20-hour road rides (2021 Festive 500 & 36,000ft on Mt. Lemmon), Chrissie Wellington reportedly consumed 105 grams per hour for her 5-hour bike leg at the 2007 140.6 Pro World Champs. She consumed this alongside some fat and protein, which probably limited her intake rate capability. Impressively high consumption rates for 2007.

In case you’re not familiar with how protein, fat, and fiber consumption affect your gut, the evidence is clear that it slows it down and reduces its capacity for absorption. if you’re intaking fat, fiber, or protein, alongside your carbs, your kcal total could have been higher if you stuck with just an optimal mix of carb intake instead.

Asker Jeukendrup, a household name in endurance sport nutrition and famed GSSI sport scientist & slowtwitch feature, championed much of the 90 grams per hour publicity. Despite this, it was his guidance that put Wellington onto 500 kcal & 105 grams of carbs per hour on the bike in preparation for her blistering marathons off the bike. Remember, that was 2007.

Given the last 15 years of improvements in learning what “optimal” approaches for intake might be, it’s a pretty open-shut case at this point that gut tolerability of>125 grams per hour is achievable for men and women alike.

Most regular folks can handle and benefit from 100-120 grams of carbs per hour, during endurance training or racing lasting longer than 3 hours. The research is plainly clear, those rates are often possible without much gut training. Often, no gut training is needed at all. If sodium and fluid intake are managed well, glucose:fructose ratio is right, and effort is not super pulsatile or stochastic (read: up and down and spiky), many folks can handle very high carb intake rates, without gut training. As in, not a world tour XCO MTB race.

Research is still thin for high carb research on longer-duration training and racing. Currently, all data point to an amplification of the performance enhancement caused by carbs when activities go beyond 4-5 hours.

I chatted about this amplified performance enhancement effect in a recent youtube-level rabbit-holing into Dr. Podlogar’s 120 vs. 90 paper. Skip ahead to my charts in the middle of the video, if you’re short on attention span, or time, or both.

With gut training, those numbers expand to probably more like 105-140 grams per hour for most folks. I have had a couple clients regularly use 150 grams per hour, and report they feel their best when they do that.

Does that mean that you ought to do this every session? That’s a discussion for the next one.

The post How High is High Carb Fueling? first appeared on Slowtwitch News.