Carbohydrate feeding during prolonged strenuous exercise can delay fatigue.

  title={Carbohydrate feeding during prolonged strenuous exercise can delay fatigue.},
  author={Edward F. Coyle and James M Hagberg and Ben F. Hurley and Wade H. Martin and Ali Asghar Ehsani and John O. Holloszy},
  journal={Journal of applied physiology: respiratory, environmental and exercise physiology},
  volume={55 1 Pt 1},
  • E. CoyleJ. Hagberg J. Holloszy
  • Published 1 July 1983
  • Medicine
  • Journal of applied physiology: respiratory, environmental and exercise physiology
This study was undertaken to determine whether carbohydrate feeding during exercise can delay the development of fatigue. Ten trained cyclists performed two bicycle ergometer exercise tests 1 wk apart. The initial work rate required 74 +/- 2% of maximum O2 consumption (VO2 max) (range 70-79% of VO2 max). The point of fatigue was defined as the time at which the exercise intensity the subjects could maintain decreased below their initial work rate by 10% of VO2 max. During one exercise test the… 

Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate.

It is concluded that when they are fed carbohydrate, highly trained endurance athletes are capable of oxidizing carbohydrate at relatively high rates from sources other than muscle glycogen during the latter stages of prolonged strenuous exercise and that this postpones fatigue.

Effectiveness of Carbohydrate Feeding in Delaying Fatigue during Prolonged Exercise

Although carbohydrate feedings prevent hypoglycaemia and are readily used for energy during mild exercise, there is little data indicating that feedings improve endurance during low intensity exercise.

Comparison between carbohydrate feedings before and during exercise on running performance during a 30-km treadmill time trial.

Performance times were identical for M and C, and there was no difference in the self-selected speeds, however, blood glucose concentration was higher in C during the first 20 km of the 30-km run.

Effects of carbohydrate feeding before and during prolonged exercise on subsequent maximal exercise performance capacity.

It is concluded that CHO ingestion improves maximal exercise performance after prolonged exercise and increases glucose levels at rest and immediately after submaximal exercise.

Metabolism and performance following carbohydrate ingestion late in exercise.

Data indicate that a single carbohydrate feeding late in exercise can supply sufficient carbohydrate to restore euglycemia and increase carbohydrate oxidation, thereby delaying fatigue.

Pre-Exercise ORS drink and muscle efficiency by bicycle ergography

There is an increase in the muscle efficiency parameters, RPP, METs and VO2max values following ORS ingestion and exercise by bicycle ergometry, in the present study.

Muscle metabolism during prolonged exercise in humans: influence of carbohydrate availability.

The data suggest that carbohydrate ingestion may increase endurance capacity, at least in part, by improving muscle energy balance and there was a small but significant increase in muscle inosine monophosphate levels in both trials.

No effect of carbohydrate feeding on glycogen synthase in human muscle during exercise.

It is concluded that under the present conditions CHO feedings do not alter the exercise-mediated changes in GSF activity, and the increase in G SF during exercise is attributed at least in part to the decrease in muscle glycogen (which increases the suitability of GS as substrate for GS phosphatase).

Carbohydrate supplementation spares muscle glycogen during variable-intensity exercise.

It is suggested that CHO supplementation can enhance prolonged continuous variable-intensity exercise by reducing dependency on muscle glycogen as a fuel source.

Timing and method of increased carbohydrate intake to cope with heavy training, competition and recovery.

  • E. Coyle
  • Medicine
    Journal of sports sciences
  • 1991
This paper has proposed extraordinary dietary practices which generally advocate high carbohydrate intake at all times before, during and after exercise to have as much carbohydrate in the body as possible during the latter stages of prolonged intense exercise.



Influence of caffeine and carbohydrate feedings on endurance performance.

Data demonstrate an enhanced rate of lipid catabolism and work production following the ingestion of caffeine, and fat oxidation was elevated 31% and appeared to provide the substrate needed for the increased work production during this period of exercise.

Effect of glycerol feeding on endurance and metabolism during prolonged exercise in man.

It appears that man cannot utilize glycerol as gluconeogenic substrate rapidly enough to serve as a major energy source during strenuous exercise.

Effects of preexercise feedings on endurance performance.

The present data support earlier findings which demonstrate that glucose feedings 30-45 minutes before endurance exercise increase the rate of CHO oxidation and impede the mobilization of FFA, thereby reducing exercise time to exhaustion.

Muscle glycogen during prolonged severe exercise.

A close relationship between utilized glycogen and combusted carbohydrate was found, and it seems highly probable that at high relative workloads primarily the glycogen stores in the exercising muscles will limit the capacity for prolonged strenuous work.

The effect of different diets and of insulin on the hormonal response to prolonged exercise.

During exercise norepinephrine increases and insulin decreases independent of plasma glucose changes whereas receptors sensitive to glucose privation but not to acute changes in insulin levels enhance the exercise-induced secretion of glucagon, epinephrine, growth hormone and cortisol.

Effects of elevated plasma FFA and insulin on muscle glycogen usage during exercise.

Seven men were studied during 30 min of treadmill exercise to determine the effects of increased availability of plasma free fatty acids (FFA) and elevated plasma insulin on the utilization of muscle glycogen and total carbohydrate oxidation.

Diet, muscle glycogen and physical performance.

It has been shown that the glycogen content and, consequently, the long-term work capacity can be appreciably varied by instituting different diets after glycogen depletion.

Influence of glucose ingestion on fuel-hormone response during prolonged exercise.

It is concluded that glucose ingestion during prolonged exercise results in augmented uptake and oxidation of glucose by the exercising legs, diminished lipolysis, augmented splanchnic glucose escape in association with decreased hepatic gluconeogenesis, and retention of half of the ingested glucose within the splANchnic bed.

Muscle Glycogen and Muscle Electrolytes during Prolonged Physical Exercise1

The results suggest that the capacity for prolonged work is directly correlated to the glycogen store in the working muscles.

A study of the glycogen metabolism during exercise in man.

The glycogen content of the quadriceps femoris muscle was determined in needle biopsy specimens taken from normal subjects in connexion with muscular work and the carbohydrate metabolism of the liver was studied before and during periods of exercise.