Carbohydrates: Timing Recommendations for Enhanced Performance

Due to the unique energy demands of strength and endurance based sports, athletes who participate in these activities have different carbohydrate requirements needed to fuel optimal performance. Aerobic endurance athletes and those who train for 60 minutes or more a day (think runners, cyclists, MMA fighters) should strive to consume 8-10 grams of carbohydrates per kilogram body weight daily to replenish glycogen levels. On the other hand, athletes who do not train aerobically for more than an hour each day (weight training, sprinting, football) should strive for 5-6 grams of carbohydrates per kilogram body weight daily.

When and how many carbohydrates should I consume before, during, and after exercise?

The following table outlines general recommendations for carbohydrate consumption before, during, and after exercise. However, athletes may need to experiment with different protocols (timing, types, & amounts) to produce individual optimal performance.

General Carbohydrate Intake

· Eat 55-65% of total daily energy as carbohydrate with a variety of natural carbohydrate food sources including fruits and vegetables and their juices as well as whole grain products and low-fat dairy food.

· A general recommendation for athletes expressed in grams would be 6-10 grams of carbohydrate per kilogram body weight depending on gender and type of sport and training intensity and volume.

Carbohydrate 3-4 hours Before Exercise

· 200-300 grams of carbohydrate 3-4 hours before endurance exercise for an adult maximizes glycogen stores at the onset of exercise and thus enhances performance. Body size, or more appropriately glycogen storage potential, accounts for this broad range.

Carbohydrate 30-60 minutes Before Exercise

· Ingest 50-75 grams of carbohydrate 30-60 minutes before exercise.

Carbohydrate Immediately Before Exercise

· If carbohydrate is to be consumed immediately before exercise (<5 minutes), 50 grams (less for women) can enhance performance without overloading the stomach at the onset of exercise.

Carbohydrate During Exercise

· An endurance athlete should strive to ingest 30-60 grams of carbohydrate per hour of endurance performance to maintain blood glucose levels. Strength trained individual may also benefit from this amount if exercise goes beyond 60 minutes and is high in intensity.

Carbohydrate After Exercise

· Ingest carbohydrate as soon as possible after completion of a glycogen-depleting exercise session.

· Ingest 1-1.5 grams of carbohydrate per kilogram body weight during the first 30 minutes after endurance exercise and every 2 hours for at least 4-6 hours after that.

· Ingesting carbohydrate late in an endurance bout may be beneficial if recovery time before subsequent exercise is limited (



Carbohydrates Are Not Bad For You

Carbohydrates have been cast in a negative light the past few years with so-called experts stating they cause weight gain, excess body fat, adverse blood lipid profiles, and a host of other problems that can wreak havoc on our health (all of which are simply not true). However, what these experts fail to tell you are that carbohydrates are the preferred source of fuel during high intensity, anaerobic exercises, such as sprinting or weight lifting. Adequate carbohydrate consumption, broken down into glucose in the bloodstream or stored in muscle tissue as glycogen, ensures you have the stamina to power through workouts without hitting a wall. In fact, various professional fitness organizations recommend 50–60% of total daily calories should come from carbohydrates to produce optimal performance in athletes.

On the other hand, low carbohydrate consumption can cause the body to use protein as energy, which in turn affects the ability of the muscle to repair and recover. Simply put, carbohydrates are king when it comes to exercise performance.

The Bottom Line on Carbohydrates

It is hard to argue that carbohydrates are not the most valuable macronutrient that fuels performance. While most research on the benefits of adequate carbohydrate consumption has been performed in endurance sports, there is an emerging body of evidence the carbohydrates play a vital role in sports such as weightlifting, football, and soccer. Without a doubt, carbohydrate is the most important energy-yielding nutrient for optimizing performance in most sports with a greater work output. Furthermore, lack of dietary carbohydrate has been linked to performance limitations in these sports. According to Smith-Ryan and Antonio (2013), “strategic carbohydrate consumption before, during, and after exercise training should be a foremost concern for athletes to maximize muscle glycogen levels before the onset of exercise, as well to provide energy to muscle during exercise and hasten recovery of glycogen after exercise is complete.”

References:

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Koivisto, V. A., Karonen, S. L., & Nikkila, E. A. (1981). Carbohydrate ingestion before exercise: comparison of glucose, fructose, and sweet placebo. Journal of Applied Physiology, 51(4), 783-787.

Neufer, P. D., Costill, D. L., Flynn, M. G., Kirwan, J. P., Mitchell, J. B., & Houmard, J. (1987). Improvements in exercise performance: effects of carbohydrate feedings and diet. Journal of applied physiology, 62(3), 983-988.

Coggan, A. R., & Coyle, E. F. (1991). 1 Carbohydrate Ingestion During Prolonged Exercise: Effects on Metabolism and Performance. Exercise and sport sciences reviews, 19(1), 1-40.

Coggan, A. R., & Coyle, E. F. (1987). Reversal of fatigue during prolonged exercise by carbohydrate infusion or ingestion. Journal of Applied Physiology, 63(6), 2388-2395.

Sherman, W. M. (1987). Carbohydrate, muscle glycogen, and improved performance. The Physician and Sportsmedicine, 15(2), 157-164.

Smith-Ryan, A., & Antonio, J. (Eds.). (2013). Sports Nutrition & Performance Enhancing Supplements. Linus Learning.