Hot weather and exercise precautions

I have had a recent spike of clients reporting muscle cramps and requesting advice on how to avoid them. Cramp occurs when a muscle goes into spasm (usually during the contraction phase) and refrains from relaxing for some time after. This can be either just an irritating twinge, or can be a serious debilitating pain.  Everyone has experienced cramp particularly those that exercise regularly or who take part in high intensity or endurance events.

So what causes cramp?  The main factors are dehydration, sodium (Na) potassium (K) imbalance and fatigue. Dehydration and Na / K imbalance probably explains the current surge of occurrences during this spell of sweltering weather. Typical loss of fluid during exercise is around 1 litres per hour of exercise (although this varies dramatically between individuals).  Sweat volumes increase considerably when exercise is carried out in hot conditions. This illustrates how much fluid is required during spells of hot weather such as we are experiencing currently and for those that are not used to this volume of fluid, cramp and underperformance may be inevitable. It’s not a great idea to try to load on fluids before exercise, as hydration needs to be gradual so that the water has time to adequately hydrate our muscles. Furthermore performing sport with a belly full of fluid is pretty difficult. Therefore athletes and exercise fanatics need to have a fluid policy that fits their event or schedule.

It’s not only water we lose through sweating, the other important loss is electrolytes. Electrolytes are mineral salts which break into small, electrically-charged ions when dissolved in water. These electrolytes include sodium, potassium and chloride which support muscle and nerve function as well as maintain normal blood pressure.   Calcium aids muscle contraction and potassium and phosphate regulate energy and ph balance. If the balance of electrolytes is disturbed and unable to quickly normalise, cramps may ensue.

Our bodies lose water at a much faster rate than electrolytes, however, so it’s usually not necessary to replace electrolytes if exercising for durations of under an hour. But for longer workouts or sporting activity, especially in the heat, would be important to add a little salt to your drink.  Just a pinch will suffice and if you can taste the salt, you have added too much. If the amount of sugar in the drink is around 4-5%  and there is a pinch of salt, you have an ideal isotonic sports drink.  Made from a standard carton of supermarket concentrated juice (around 14% sugar) you can make your isotonic drinks at around 20p per litre why pay £2.50/litre to the commercial drinks companies – its daylight robbery.

Finally, fatigue linked with dehydration due to the significantly reduced output of power from muscles deprived of sufficient water. Warming up gradually even in the heat is important, and you needn’t let the warm weather and cramp stop you from exercising..

Information provided courtesy of Discovery Learning – providers of UK fitness and personal training courses.

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