Hydration strategies used during exercise, training and competition seek to prevent over-/under-hydration and preserve performance, but it isn’t as simple as drinking throughout exercise.
Losing more than 2% of body mass through sweat is a sign of significant dehydration, and dehydration can increase the risk of heat illness and decrease performance by affecting muscle and cognitive function.1 The goal is to minimize dehydration and preserve performance.
Main Hydration Strategies
Programmed drinking: Pre-established drinking plan based on an individual’s sweat rate and sweat electrolyte content
Drink to thirst: Using the sensation of thirst as the only stimulus to drink
Fluid intake should approximate sweat loss to prevent significant dehydration (>2% body mass loss) or overhydration (body mass gain) during exercise
~30-60gm carbohydrate per hour of exercise = ~0.5 – 1.0L per hour of a 6-8% carbohydrate solution.2,3,4
Programmed drinking is best for:
Longer duration activities greater than 90 min, particularly in the heat
Higher intensity exercise
Individuals with high sweat rates
Exercise where performance is a concern
Drink to thirst is best for:
Short duration activities less than 90 min
Exercise in cooler conditions
Lower intensity exercise
Determine sweat rate under conditions (exercise intensity, pace) and environments similar to anticipated competition environments. Tailor the programmed drinking plan to prevent greater than 2% body mass losses in athletes with high sweat rates or those concerned with exercise performance.