ISOTONIC - Isotonic drinks have the roughly the same concentration as your body fl uid. They are
ideal for ordinary fl uid replacement during exercise.
Energy drinks can be quite a confusing subject especially when people start throwing around
terms such as Hypotonic, Isotonic and Hypertonic.
Fundamentally they provide two things : hydration and energy.
The difference between the terms are described below.
HYPOTONIC - These type of drinks are usually weaker than your body fl uid and help to speed up
water absorption in the body. After exercise these drinks come into their own, providing rapid replacement
of spent fl uids but are not ideal for energy replacement during exercise. Unlike Isotonic
and Hypertonic drink these type of drinks are low in carbohydrates. They are great for the athlete
looking for fl uid replacement without the boost of carbs generally after a session. They can target
one cause of fatigue, which is loss of fl uids rapidly.
HYPERTONIC - These drinks generally contain higher levels of carbs than the other two types
mentioned and can be used after exercise to replace spent gylcogen. During endurance sessions
they can be used to top up carb levels when glycogen stores are depleted. They are absorbed
slowly and therefore are not appropriate for fl uid replacement. In fact using these drinks as fl uid
replacers could increase your dehydration as your body releases water into your intestines in order
to dilute the drink enough for it to be absorbed.
Some athletes use these drinks along side Isotonic fl uids to keep the hydration and carb replacement
levels balanced.