By Arnie Baker, MD
Key Cycling Nutrition Points
- Refueling after exercise is a proven recovery strategy.
- The sooner the better. Refueling during exercise is best.
- Prompt refueling benefits both endurance and strength athletes.
- Prompt refueling benefits aerobic and anaerobic work.
- Aim to ingest at least 50 grams of carbohydrate (200 calories) within the first 30 minutes after exercise and again every hour for the next 3 hours, up to caloric deficit.
- Some fat and some protein with the carbohydrate is no problem.
- “Real food” is probably better than specialty sports products.
Replace fluids lost during exercise.
The glycogen window refers to the concept that a post-exercise window of opportunity exists when ingested carbohydrate can be converted to muscle glycogen more readily than at a later time.
Replacing carbohydrate as soon as possible after exercise may reload glycogen to a greater extent than if you travel home, shower, and then sit down to a meal.
On average, the body can incorporate about 50 grams (200 calories) of carbohydrate into glycogen per hour in the first few hours after exercise—if carbohydrate is available.
Despite advertising hype, protein has not been shown to improve glycogen reloading. That is not to say that protein is not important in your overall daily program, or that it is bad for recovery. Protein may be helpful for other reasons, discussed below.
Dietary patterns (high carbohydrate, low fat vs. lower-carbohydrate, higher-fat) may not degrade training when workout intensity is low to moderate.
If you have 48 hours to recover before your next high-intensity workout—that is, a rest day in between—you have more time to replace glycogen. A lower-carbohydrate, higher-fat diet may not decrease performance.
The glycogen window is relatively well-studied. The fat window is less-well understood. (The glycogen was easier to study and was examined first.)
About 1,500 calories are stored in muscle for energy use as glycogen. About 2,500 calories are stored for energy use as intramuscular lipid.
Fat replacement after exercise has been shown to effectively restore intramuscular lipid using water-suppressed nuclear magnetic resonance spectroscopic imaging.
If you do not get enough fat in your diet, muscle glycogen stores may be great, but muscle fat stores may be deficient. Aerobic endurance exercise demands both to perform well.
How much fat is needed and how quickly is unknown. Whether carbohydrate can be converted to intramuscular fat, or whether adipose stores can be mobilized, and how quickly, is also not known.
Typical of many refueling studies, one study showed that increasing calories from 57% carbohydrate to 68% or 88% carbohydrate results in more muscle glycogen after repeated bouts of exercise, in proportion to the amount of carbohydrate ingested.
Although both the 68% and 88% carbohydrate diets increased intramuscular glycogen, the 88% carbohydrate diet led to decreased muscle triglyceride concentrations.
Even Better: Don’t Get Behind
If you ride a bicycle for 6 hours, why wait to reload for cycling nutrition when you get home?Why not stop after a few hours and have a good snack or lunch?
The more you can keep up, the less you are behind, the less you need to replace when you get home. Up to about 300 calories per hour may be useful during exercise for today’s workout.
If you can eat more while you exercise, even though you may not need calories for today’s workout, you may improve your ability to ride with intensity again tomorrow. Tour de France riders, for example, often consume more than 700 calories per hour while riding.
Summary: Overall Caloric Mix
You need to replace lost carbohydrate and fat stores in muscle. Adequate carbohydrate and fat calories, rather than percentage guidelines, are what is needed. At least 200 calories per hour of carbohydrate can be incorporated into muscle glycogen in the first few hours after exercise.
How many calories from fat can be incorporated into muscle per hour is not known. Since there is at least as much intramuscular fats intramuscular glycogen, it seems prudent to aim to ingest at least 100 calories of fat per hour for the first few hours after exercise.
There is evidence that post-exercise mood may be better with whole food or mixed-source caloric drinks (carbohydrate, protein, and fat) than with carbohydrate-only fluids.
Although protein has not proved useful in improving glycogen replacement, unless total calories are insufficient, it may be important in rebuilding muscle or for other reasons. Studies are lacking.
My favorite post exercise strategy: Choose “real food,” not specialty sports products for cycling nutrition. Although sports products will be convenient and palatable for some, “real food” is probably better—more complete, balanced, tastier, and less expensive. For example: A quart of fat-free milk, a sandwich, fruit, and a few cookies.
Replace sodium lost during exercise, generally with salty foods.
Keep Recovery Supplies Handy
It may require planning. Keep a gallon or two of fluids and a cooler in your vehicle if you travel to workouts or events, so that you can start the recovery process sooner rather than later.