Fluid and fuel intake during exercise

  title={Fluid and fuel intake during exercise},
  author={Edward F. Coyle},
  journal={Journal of Sports Sciences},
  pages={39 - 55}
  • E. Coyle
  • Published 1 January 2004
  • Education
  • Journal of Sports Sciences
The amounts of water, carbohydrate and salt that athletes are advised to ingest during exercise are based upon their effectiveness in attenuating both fatigue as well as illness due to hyperthermia, dehydration or hyperhydration. When possible, fluid should be ingested at rates that most closely match sweating rate. When that is not possible or practical or sufficiently ergogenic, some athletes might tolerate body water losses amounting to 2% of body weight without significant risk to physical… 

Hydration Is More Important Than Exogenous Carbohydrate Intake During Push-to-the-Finish Cycle Exercise in the Heat

It is suggested that hydration is more important than carbohydrate availability during exercise in the heat, highlighting the importance of carbohydrate availability in cooler conditions as the length of a push-to-the-finish cycling task increases.

Symposium on ‘Performance, exercise and health’ Hydration, fluids and performance

  • S. Shirreffs
  • Education
    Proceedings of the Nutrition Society
  • 2008
There is a less conclusive picture as to the effects of hypohydration on other types of physical performance, including strength and power activities, team sports and the skills component of many sports, and for mental performance.

Fluid and electrolyte needs for training, competition, and recovery

Both water and sodium need to be replaced to re-establish “normal” total body water (euhydration) and aggressive drinking of fluids and consuming electrolytes should be encouraged to facilitate recovery for subsequent competition.

Hydration in sport and exercise: water, sports drinks and other drinks

There is evidence to suggest that exercise-induced dehydration can have a negative impact on exercise performance, and restoration of fluid balance should be achieved after exercise, and sports drinks are ideally placed to fill both roles.

The importance of salt in the athlete’s diet

Simple measures such as recording daily pre- and postexercise body weight can aid in making fluid and sodium ingestion decisions; in some cases, a comprehensive evaluation is necessary.

The Importance of Salt in the Athlete's Diet

Simple measures such as recording daily pre- and postexercise body weight can aid in making fluid and sodium ingestion decisions; in some cases, a comprehensive evaluation is necessary.

Hydration and Physical Performance

  • B. Murray
  • Psychology
    Journal of the American College of Nutrition
  • 2007
It is generalize that when performance is at stake, it is better to be well-hydrated than dehydrated, and this generalization holds true in the occupational, military, and sports settings.

Guidelines for Glycerol Use in Hyperhydration and Rehydration Associated with Exercise

Glycerol ingestion before, during or following exercise is likely to improve the hydration state of the endurance athlete, and guidelines for athletes wishing to use this compound are provided.

Thermoregulation during Exercise in the Heat

During heat acclimatisation, the temperature thresholds for both cutaneous vasodilation and the onset of sweating are lowered, which, in combination with plasma volume expansion, improve cardiovascular stability and nutritional intervention seem to be most effective.

The importance of hydration in sport

Water is an essential constituent of living matter; and rehydration is very important for athletic performance. The body loses through sweat salt and minerals, together with water; and only water



Carbohydrate and fluid ingestion during exercise: are there trade-offs?

Intense exercise (i.e.; above 60% VO2max) can be maintained for prolonged periods provided sufficient carbohydrate is available for energy and the heat generated from muscle metabolism does not cause

Benefits of fluid replacement with carbohydrate during exercise.

Ingestion of approximately 30-60 g of carbohydrate during each hour of exercise will generally be sufficient to maintain blood glucose oxidation late in exercise and delay fatigue. Since the average

Fluid replacement in sport and exercise--a consensus statement.

Evidence clearly indicates that sports drinks which contain an energy source in Dr R. J. Maughan the form of carbohydrate together with electrolytes, particularly sodium, are more effective than plain water in improving performance.

The effects of substrate and fluid provision on thermoregulatory and metabolic responses to prolonged exercise in a hot environment

It is suggested that fluid replacement with a large volume of a dilute carbohydrate drink is beneficial during exercise in the heat, but the precise mechanisms for the improved exercise capacity are unclear.

Fluid and electrolyte loss and replacement in exercise.

The optimum fluid for rehydration during exercise depends on many factors, particularly the intensity and duration of the exercise, the environmental conditions, and the individual physiology of the athlete.

Fluid and Electrolyte Balance in Ultra-Endurance Sport

If insufficient fluids are taken during exercise, sodium is necessary in the recovery period to reduce the urinary output and increase the rate of restoration of fluid balance, and an increased beverage concentration may be beneficial.

Fluid and electrolyte supplementation for exercise heat stress.

It has been suggested that hyperhydration (increased total body water) may reduce physiologic strain during exercise heat stress, but data supporting that notion are not robust.

Effects of dehydration on exercise performance.

  • S. Barr
  • Environmental Science
    Canadian journal of applied physiology = Revue canadienne de physiologie appliquee
  • 1999
The effects of hypohydration may vary, depending on whether it is induced through diuretics or sauna exposure, which substantially reduce plasma volume, or prior exercise, which has much less impact on plasma volume.

Sodium-free fluid ingestion decreases plasma sodium during exercise in the heat.

The results show that decreased plasma sodium concentration can result from replacement of sweat losses with plain W, when sweat losses are large, and can precipitate the development of hyponatremia, particularly in individuals who have a decreased urine production during exercise.

Effects of glycerol-induced hyperhydration prior to exercise in the heat on sweating and core temperature.

The hypothesis that glycerol-induced hyperhydration reduces the thermal burden of moderate exercise in the heat is supported.