Hypertonic drinks contain ~10g of carbohydrate per 100ml in order to provide maximum energy uptake and are excellent for refuelling after exercise. However, the presence of so much carbohydrate can delay water absorption. Hypertonic drinks can be thought of more as food and can be used as a convenient pre- or post-exercise snack. They best used after training or alternated with water during longer events.
Isotonic drinks quickly replace the fluid lost by sweating. Containing more sugar than hypotonic drinks (~6g per 100ml) isotonic drinks are ideally suited to exercise where carbohydrate and fluid replacement are necessary to avoid a decline in performance. Isotonic drinks provide energy, which may not be required by people trying to manage their weight or people exercising for less than 60 min.
Hypotonic drinks are intended to quickly replace water and electrolytes lost during exercise. Hypotonic drinks only contain ~2g carbohydrate per 100ml which is insufficient to fuel a long or hard workout. This type of sports drink is best suited to exercise 60 min or less or where fluid replacement is more important than fuelling such as exercise in the heat.
Electrolyte tablets can be added to water, cordial or diluted fruit juice to create a low calorie sports drink suitable to your flavor preference and hydration needs. They can also be used to increase the electrolyte content of an existing sports drink, which is especially useful when the conditions are hot or you’re a heavy sweater. In endurance races, such as triathlons and ultra-marathon races salt tablets are commonly used as a supplement to sports drinks.