Fit Fuel for Cycling

By B. Shiva Mayer & Robert Biard – November 17, 2012

Bike racers and triathletes alike understand that training on a bike can be a time-consuming endeavor. Because of the inherent efficiency of riding a bike—the ability to coast downhill, the cooling effect of the passing air, and for road cyclists, the aerodynamic assistance of riders ahead—the human body can withstand far more continuous hours on the bike than it can performing nearly any other aerobic endeavor. This ability comes at a price, however; regardless of how little impact one’s muscles have felt, the body consumes its fuel stores at a steady rate. Further, loss of body water through breathing, urination, and perspiration all accelerate as energy demands increase. In order to combat these losses, proper nutrition before, during, and after training rides and races is essential.


Our bodies store energy in different ways. Immediate energy needs come from a small reserve of adenosine triphosphate (ATP) but only about five calories of energy are available this way; that’s about enough energy to ride one-tenth of a mile. Strenuous aerobic exercise is partially fueled by metabolizing carbohydrate stores—mainly though roughly two thousand calories of muscle and liver glycogen—into ATP. The rest comes from an additional one hundred thousand calories that are stored in fat, assuming they could be completely oxidized into ATP. It’s worth noting that fat metabolism proceeds at a slow and constant pace and, therefore, contributes less as the effort becomes higher. When racing or training at high intensity, most cyclists find carbohydrates to be an essential part of their diet. In particular, carbohydrate-rich foods with a low glycemic index—whole grains, nuts, and vegetables among them—keep blood glucose levels stable pre-ride. Although low-carb diets have become popular, they don’t generally meet the nutritional needs of cyclists. One potential exception is for those training under roughly 65 percent of their peak aerobic capacity; at this low intensity, the body can metabolize fat at peak effectiveness, reducing carbohydrate demands.


For rides and races shorter than about 90 minutes—depending on intensity, of course—one can generally rely on the body’s endogenous carbohydrate reserves, assuming they were well stocked to begin with. As the distance and effort grows, however, consuming carbohydrate-rich food on the bike becomes essential. Exactly what kind of food to consume is almost as individual as saddle preference. Solid or gel products, such as GU Energy Gel or Cliff Shot Blocks, are familiar to most athletes. Others prefer consuming an energy-dense liquid, such as First Endurance’s EFS Shots, or a more traditional drink like Gatorade. I’ve even seen racers whip “real food” out of their jersey pockets—peanut butter and jelly sandwiches, unappetizingly compressed muffins, and bottles of Coca-Cola. Regardless of the type of food, be sure to become acquainted with it during training instead of on race day. When considering how much and when to eat, it helps to keep in mind that the body can only absorb about 275 calories an hour, an amount far short of the 500 to 1,000 calories an hour one might be burning in a race. The goal should not be to replace every lost calorie while riding; instead, riders should aim to eat roughly what they can digest. From this follows the adage “eat before you get hungry” because, by the time your glycogen stores have been depleted, it’s already too late. Equally important, especially in hot climates like Texas, is proper hydration. While it’s tempting to assume that the corollary to the above adage is “drink before you get thirsty,” some coaches suggest that endurance athletes should instead drink whenever they are thirsty to allow the body to naturally regulate sodium concentrations. When sodium depletion is high—for example, after sweating for hours—it can be helpful to consume additional salt as well, either through salty food, a drink mix with added electrolytes (such as products offered by Skratch Labs or First Endurance), or directly through salt tablets. A helpful indicator of overall hydration is that one shouldn’t lose more than roughly three percent of body mass over the course of a long ride; if you’re losing more than this, then aim to consume both more water and some additional sodium.


Post-ride, it’s necessary to rehydrate, replenish lost calories, and provide appropriate protein to support muscle development—and the sooner, the better. Cyclists should aim for a 3:1 ratio of carbohydrates to protein, which has made chocolate milk a popular choice of beverage among cyclists. Alternatively, products like Core Power—a milk-based drink that has a 1:1 carbohydrate to protein ratio—allows athletes additional flexibility in choosing a carbohydrate source. It can be difficult to replenish one thousand or more lost calories solely in chocolate milk! Estimating your post-ride caloric needs is easy, given that most cyclists now ride with GPS and heart-rate monitors. The output of these devices can be uploaded to any number of free Web services, such as TrainingPeaks, to provide an estimation of the calories burned during the ride. (Cyclists with power meters can simply read off the total work done in kilojoules, which convert neatly to calories on a one-to-one basis.) By subtracting any calories eaten during the ride, the post-ride deficit can be obtained; for those seeking to lose weight, a slight deficit may be desirable. Similar advice can be applied to hydration: by looking at weight lost during a ride, fluid replacement requirements can be estimated. The same considerations about sodium regulation that apply during a ride apply post-ride as well, although the concern is usually not as acute given that sodium is usually a part of a post-ride meal. Eating and drinking the right quantities at the right time is essential to performing well on the bike. While the above guidelines are a good start, each rider will have unique needs and responses. To elicit the best performance, it’s imperative that each athlete finds out what works well for him or her through experience. Like physical conditioning, eating habits are best practiced and refined during training, not on race day. Consider what you should be eating before, during, and after every ride, and you’ll maximize both your enjoyment and performance along the way.

B. Shiva Mayer B. Shiva Mayer, 26, is a member of the Board of Directors of 787 Racing. A native of British Columbia, Canada, he has lived in Austin for nearly five years. An avid road and mountain bike racer, Mayer has competed extensively across both the United States and Canada. For more information about 787 Racing or junior cycling in general, contact Mayer at

Robert Biard Robert Biard, native Texan and UT Austin graduate, is a co-founder and member of the Board of Directors of 787 Racing. Biard has been a consistent presence in road, mountain, and cyclo-cross racing, competing in more than 300 races over the last six years. Biard is a passionate advocate for the bike racing community, working with the Austin City Council and Austin Parks to promote new events and explore ways to introduce new communities to the sport. When not cycling, he and his two Weimaraners, Cooper and Tucker, can be found on the Barton Creek Greenbelt. For more information, contact Biard at


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