Sports Nutrition

Are You Fueling Enough On The Bike?

Carbohydrate intake is a perpetually hot topic in the field of sports nutrition.  From classic low carb weight loss strategies [1], to cutting edge carb periodization [2], if you’re wanting to ride further or faster, getting smarter about carbs is in your best interest.

**Make sure to check out our more recent Carbohydrate Fueling for Cycling Guide**

Carbs Before a Ride

We’ll save weight loss strategies and carb periodization for another day.  This article will focus on fueling during your rides.  First, a few basics about carbs before the race whistle goes off:

  1. Carbs should comprise around 55-65% (6 to 10 g/kg of body weight/d) of your diet [3, 11].  If you’re significantly under this range you might want to rethink your daily food choices.
  2. Start topping off your glycogen stores by consuming 200-300g of carbs in a mixed macronnutrient meal, 3-4 hours before a race [3, 4].
  3. Eat 50-75g of carbs 30-60 minutes before your race [3, 4].
  4. Right before (<5 minutes) a race, knock down another 30-50g of carbs. This will give you a safety net if you find it difficult to eat while riding [5].

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.

Carbs During a Ride

While eating carbs before riding helps to top off glycogen stores [3], during exercise carbs serve to maintain blood glucose levels [3].  In simple terms, the more carbs you absorb while riding, the more punch you’ll have for a final KOM attempt or sprint for the line [6-8].  So how many carbs exactly?

It Depends

Optimal carb intake depends on the intensity and duration of your ride [9, 11].  The harder and longer you ride, the more carbs you need.  It’s easiest to think of carb intake on a continuum.  Here are several general targets.

Carb Recommendations for Cycling [9]

  1. Ride between 30-75 minutes = Small amounts
  2. Ride around 2hrs = 30g/hr
  3. Ride around 2-3hrs = 60g/hr
  4. Ride over 2 1/2hrs = 90g/hr
    • At carb intakes over 60g/hr, your carbs must come from “multiple transporter” sources.  In simple terms, you need fructose in addition to glucose and/or maltodextrin in a roughly 2:1 glucose/fructose ratio [9, 10].  Example: 60g glucose and 30g fructose to fully absorb 90g/hr.  Click here for ratios on many of the most popular exercise food products.

Food

Let’s translate those carb numbers to actual food.  The picture below illustrates how you might mix and match carb sources to hit the recommendations above.

Carb Food Choices

Putting it all together

When we crunch the details we’re left with this chart.  These are general recommendations, not black and white rules.  Furthermore, you have to train your gut to maximize carb absorption [9, 12].  Increasing your carb intake on the bike won’t happen overnight.

CarbRecomendationsCycling

Summary

  1. Eating carbs before and during a race is essential to maximizing  performance.
  2. Identify the intensity and duration of your ride/race to dial in your carb-fueling strategy.
  3. Practice your carb fueling approach. Train your gut to maximize carb absorption during rides.

Edit History

*4/5/18-Revised carb recommendations summary graphic
*4/13/18-Added new research on training the gut [12]

Training can be confusing. In our free eBook, we’ll show you four ways to use your data and insights from science to ride better than ever.

References

  1. Krieger, J.W., et al., Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression 1. Am J Clin Nutr, 2006. 83(2): p. 260-74.
  2. Marquet, L.A., et al., Enhanced Endurance Performance by Periodization of CHO Intake: “Sleep Low” Strategy. Med Sci Sports Exerc, 2016.
  3. Abbie E. Smith-Ryan, P., CSCS*D, CISSN Jose Antonio, PhD, FNSCA, FISSN, CSCS, Sports Nutrition & Performance Enhancing Supplements. 2013, Ronkonkoma, NY: Linus Learning. 404.
  4. Wildman, R., C. Kerksick, and B. Campbell, Carbohydrates, Physical Training, and Sport Performance. Strength & Conditioning Journal, 2010. 32(1): p. 21-29.
  5. Neufer, P.D., et al., Improvements in exercise performance: effects of carbohydrate feedings and diet. J Appl Physiol (1985), 1987. 62(3): p. 983-8.
  6. Constantin-Teodosiu, D., G. Cederblad, and E. Hultman, PDC activity and acetyl group accumulation in skeletal muscle during prolonged exercise. Journal of Applied Physiology, 1992. 73(6): p. 2403-2407.
  7. Coyle, E.F., et al., Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Journal of Applied Physiology, 1986. 61(1): p. 165-172.
  8. Sahlin, K., A. Katz, and S. Broberg, Tricarboxylic acid cycle intermediates in human muscle during prolonged exercise. Am J Physiol, 1990. 259(5 Pt 1): p. C834-41.
  9. Jeukendrup, A., A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Med, 2014. 44 Suppl 1: p. S25-33.
  10. Jentjens, R.L.P.G., et al., Oxidation of combined ingestion of glucose and fructose during exercise. Journal of Applied Physiology, 2004. 96(4): p. 1277-1284.
  11. Thomas, D.T., K.A. Erdman, and L.M. Burke, Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet, 2016. 116(3): p. 501-28.
  12. Miall, A., et al., Two weeks of repetitive gut-challenge reduce exercise-associated gastrointestinal symptoms and malabsorption. Scand J Med Sci Sports, 2018. 28(2): p. 630-640.