Active people who play sport, or undertake demanding physical work, need to ensure they stay well hydrated and replenish their electrolytes.

Electrolytes are lost through sweat during exercise/heat, particularly during long summer days of humidity and heat. Summer is when we are naturally more active with sports, walking instead of driving, and undertaking home garden projects. It also applies socially – attending large parties, concerts or festivals, and drinking alcohol while dancing all night in crowded clubs. 

When electrolytes are depleted from the body, we become tired, cramp easily and risk dehydration.  Replacing electrolytes is essential to keep the body hydrated, to enhance performance and help prevent muscle cramps.

Fluids are absorbed through the gut and into the bloodstream faster when their osmolality closely matches that of body fluids such as blood. Osmolality is the concentration of dissolved particles in a fluid. Sports drinks contain dissolved minerals such as sodium, potassium, magnesium, chloride and carbohydrates, whereas water doesn't, so water doesn't reach the bloodstream quite as quickly.

Sodium and other nutrients also play important roles in regulating fluid balance in the body. They help determine how much fluid enters muscle cells, and how much remains in the blood. Again, sports drinks contain these nutrients, so do a better job of allowing the body to maintain optimal fluid balance – an aspect of hydration few consider.

Another advantage of sports drinks over water, is that the sodium content of sports drinks stimulates thirst, so people usually drink more than they would plain water.