Nutrition and Hydration Guide for Gravel Racing and Endurance Mountain Biking

By Chris Carmichael
CTS Founder and Chief Endurance Officer

As more riders venture out for long adventure rides, gravel events, and endurance mountain bike races, they face distinct challenges when it comes to staying hydrated and fueled. Aid stations or water sources are often few and far between, and based on weather and terrain you may be on your own for much longer than you anticipate. Whether you’re optimistically signing up for a summer or fall event or you’re embarking on your own gravel or mountain bike challenges, use these tips to stay hydrated and fueled.

Hydration determines your nutrition plan

Before getting down to details about what to eat and when, it is important to understand some overarching concepts. Hydration drives nutrition. Your hydration status significantly impacts your ability to break down and move the food you eat from your stomach to small intestine, and then transport nutrients into your bloodstream. Dehydration and hyperthermia slow gut motility, which means the energy you desperately want stays in your gut instead of reaching working muscles. Worse than that, as it sits there it increases your risk for gastric distress, and a sour stomach is one of the leading causes of DNF in ultradistance events. The lesson: prioritize hydration status over energy intake. You can fix an energy problem quickly, but fixing hydration- and hyperthermia-related problems is a slower process.

Separate food from fluids

One of the best ways to prioritize hydration is to keep your calories in your jersey pockets. Typical carbohydrate-rich sports drinks are designed to provide about 25 grams of carbohydrate (100 calories) in about 500 milliliters of fluid. That is roughly equivalent to a serving of chews like Probar Bolts or most carbohydrate gels. I recommend incorporating sports drink into you fueling strategy, but to also make sure you have plain water or electrolyte drink so you can increase fluid intake in response to higher temperatures or harder efforts. You want the flexibility to adjust your energy and fluid intakes independently.

Probar supplies CTS Coaches and athletes with nutrition products for use during camps and events. 

Match foods to pacing strategy

In long endurance rides it is common for athletes to start with solid foods that are rich in carbohydrate, fat, and protein early in the day. These foods are slower to digest so they provide longer-lasting energy, and you can digest them because the intensity is generally pretty low. Because everyone starts together at gravel races and endurance mountain bike events (although wave starts might be necessary for any events that occur during the pandemic), the first 1-2 hours are fast as riders work hard to stay with the fast group before dropping off and settling into a more sustainable pace for the long haul. It is important to eat during this period, but you’ll want to have “fast calories” like gels, sports drink, and chewables even though you still have many hours ahead of you. Once you back off and set a more sustainable pace, switch to solid foods for “slow calories” and reserve the fast calories for later in the day.

Consume and carry from aid stations or store stops

Self-reliance is an important part of the culture of gravel and endurance mountain bike events, and aid stations are often few and far between. If you have 20 miles to ride between stops, you have to plan that a headwind, flat tire, or technical terrain could add 30-45 minutes to your expected time for that leg. If it’s 50 miles between stops, those same variables could add 90-120 minutes. It is pretty easy to carry more than enough calories for longer-than-expected sections; having reserve fluids is more of a problem.

No one wants to haul extra water because it’s heavy, but when you are loading up to leave an aid station, estimate how long it will take you to reach the next stop and then carry enough water for an additional hour (at minimum). And even if you are moving through aid stations quickly, consume a 500ml bottle of fluid and then take full ones. It’s like leaving the station with an extra bottle.

Save yourself from a stomach problem

Even if you have a tried and true fueling strategy and a list of foods you know work for you, there will be a time when your stomach stops cooperating. Dehydration, hyperthermia, and reduced gut motility are the most common combination of factors leading to gastric distress during long endurance rides and events. If you are nauseated, bloated, and struggling with a sour stomach, you have to work the problem: slow down, cool down, and sip small amounts of plain water.

Slowing down is better than stopping altogether, but reducing intensity gives your body a chance to redirect blood to gut to get digestion moving again. It also reduces internal heat production, which along with proactive measures like dousing yourself with water and opening layers, helps alleviate hyperthermia. Finally, sipping small amounts of water helps improve hydration status and restore gut motility.

On long days, how you feel in the last third of the ride depends on the nutrition, hydration, and pacing decisions you made getting there. When you dial in your fueling strategy for the long haul, you can feel strong and satisfied crossing the finish line – no matter how long it takes to get there.