We all know that hydration is important for everyday life, but it is vital for athletes of any calibre. Ensuring you are hydrated will increase your staying power when it comes to the sport / activity of your choice and reduce your recovery time post exercise.
Your body literally depends on water to survive. Every cell, tissue, and organ needs water to function properly. For example, your body uses water to maintain its temperature, remove waste, and lubricate your joints.
Water cools the body through sweat and exhalation; an insufficiency of water can reduce perspiration and lead to fatigue.
When our body is working harder, heat is created, which needs to be lost. Approximately 75% of the energy used in exercise, is used produced heat, with only the remaining 25% going to actually useful work.
The body uses electrolytes to help regulate nerve and muscle functions and maintain the right amount of alkalinity. Electrolytes include sodium, potassium, calcium, magnesium, chlorides, phosphates and iron. These are usually maintained adequately by a varied diet of proteins, fruits and vegetables. Excessive perspiration during long events can lead to a loss of salt (sodium chloride) and so some additional electrolytes, in small amounts, can be added to your drink.
Sugary drinks can create an acidic environment that can impair enzyme function and decrease your body’s water storage capacity, which is necessary to metabolise all the extra sugar. Special attention must be given to sport drinks with sugar because they may actually make you prone to losing extra fluids.
Hydration starts well before you train or enter an event. In the early morning, your body may be slightly dehydrated, so it is important to drink as soon as you get up.
During long events, it is best to keep sipping to keep pace with the loss. Taking smaller drinks more frequently also helps prevent feeling bloated.
At the end of an event, your body may still be slightly dehydrated and so drinking afterwards will not only help replenish body fluids but also help the body flush through accumulated waste metabolic products.
A general rule of thumb is to consume 500ml per hour of vigorous exercise in addition to the two liters per day
Referenced from: Simon Kidd - Cycling coach UK