In a study involving children between 8 and 10 years of age, researchers at McMaster University have concluded that milk does a better job than water or sports drinks when it comes to rehydrating active children. Milk does a better job in replacing sodium lost in sweat and helps the body retain fluid better. It also contains carbohydrates, calcium and electrolytes.
As well, milk is a high quality source of protein, which is needed by children for muscle development and growth. This is not found in other sources such as sports drinks or water.
Dehydration can negatively affect a child’s performance in a sport, but more importantly, children are more prone to dehydration due to their smaller size. This can lead to heat-related illness such as heat stroke. Hydration is the key to preventing this, and drinking milk may be an effective way of reducing the risk of dehydration.
Source: McMaster University