The Importance of Hydration During Indoor Training
Cycling / Intermediate
As the weather turns on us, sometimes heading out into the cold and rain to complete a training session can be unbearable. Now with things like Wattbike and Zwift, indoor training has never been more popular. But don't compromise your nutrition just because you are exercising indoors.
When exercising the body’s heat production is 15-20 times greater than at rest. This can be elevated even further by conditions faced when training indoors, which lets face it, are often hot, humid and very sweaty. This is because there is little air movement causing heat to build up around the body meaning sweat can’t evaporate as quickly. This is why you get more hot and sweaty then you would get training outside, making you far more susceptible to dehydration.
UNDERSTANDING DEHYDRATION
Our body’s core temperature is ≈37°C and it is the thermoregulatory systems job to maintain this homeostasis. As the body’s core temperature rises due to exercise, the majority of the heat being dissipated is by the evaporation of sweat. Blood flow has to split itself between our organs, working muscles and now our skin for sweating. As the intensity of exercise increases, sweat rates will increase which actually reduces our blood volume and stroke volume. The heart then has to work much harder to deliver oxygen to working muscles and therefore lowers intensity of exercise we can maintain.
Not only do we lose fluid through sweating but also electrolytes. The primary electrolytes present in sweat during exercise are sodium and chloride with smaller amounts of magnesium, potassium and calcium also present. It is when this electrolyte equilibrium is not maintained during exercise, often through erroneous feeding strategies, that performance is further compromised.
Basically: Dehydration negatively affects performance. Even as little as 2% loss of body weight due to dehydration has been shown to impair performance.
