Electrolytes for performance and recovery.

Many sports drinks and supplements are marketed as containing electrolytes. However many people do not fully understand the roles that electrolytes play in the body, and why they might be important to support recovery and performance.


Electrolytes get their name because these are substances that when dissolved in water, or other body fluids, create electrically charged particles called ions. There are many different electrolytes in the body but sodium and potassium are the two most common electrolytes found in the body, with sodium being found typically extracellularly (outside the cells in the body) and potassium intracellularly (inside the cells of the body).


These two electrolytes are responsible for two main things; maintaining and modulating fluid balance in the body and in the transmission of nerve impulses which govern the function of many of the body’s organs... and of course muscle contractions.


Unfortunately during exercise we lose both electrolytes and water in our sweat and this can lead to reduced performance and even serious illness or death in situations where we suffer lots of water and mineral loss. In these severe situations it is important to not just think about replacing water but also electrolytes, as water without the addition of electrolytes can actually make matters worse. Fortunately, this would be a rare situation and only occur when exercising in very hot environments or for very extended periods.


For most people consuming a healthy and balanced diet, and consuming recommended water intakes of 2-3 litres per day (plus replacement for fluid loss during exercise), then we should be getting enough electrolytes directly from our foods. Our bodies have some pretty clever ways to maintain fluid and electrolyte balance even when people have a reduced intake of electrolytes. For example the hormone aldosterone helps to retain sodium in the body if we have a low intake.


However when training in hot or humid environments, especially if unaccustomed to them, then the use of electrolytes can be of some real benefit. Some people who are prone to cramping tend to have a lack of electrolytes in the diet or are often dehydrated, this can be solved by simply consuming foods rich in electrolytes and ensuring adequate water intake… for example a glass of orange juice and small pinch of salt can replace all of the calcium, potassium magnesium and sodium lost in around 3 litres of sweat! Cramp caused directly through exercising is a topic that still gets a lot of attention as its causes are not well defined. Several theories exist that involve dehydration and electrolyte depletion and overload of the neuromuscular system with fatigue although none is clearly implicated as the main cause of exercise induced muscle cramps.


In summary as long as you have a balanced diet that contains sources of the main electrolytes, particularly sodium, potassium, calcium, magnesium and chlorine then supplementation is not usually required unless you are intending on exercising for long durations or in an extreme environments. For those who suffer  regulalry from cramps in the gym or when playign sport, it is unknown if this is caused by localised imbalances in fluids or electrolytes or some other mechanisms, but they may get some benefit from electrolyte supplementation. If you are exercising in extreme conditions where fluid loss may be rapid, then increasing sodium intake through the use of electrolyte supplements or specialist sports drinks is advised, as the sodium will also assist in aiding the uptake of water and assisting rehydration.

Dr P.