HYDRATION AND EXERCISE

Our body is predominantly fluid and maintaining a balance in fluid becomes cardinally important. Therefore the subject of hydration is elemental to our health and vital when it comes to exercising. Dehydration can lead to serious health consequences. Depending on individuals, you can lose some 1 litre of fluid through perspiration and breathing in an hour of exercise. Therefore, getting the right amount of fluid before, during and after exercise is truly important.

Before exercising, make sure you are well hydrated and drink fluid from at least 4 hours before. A simple method of checking your hydration is to observe the colour of your urine. It should be pale yellow and not dark yellow. When it’s dark, it’s an indication that you are dehydrated. If that’s the case, drink 400-600ml. of water in the 2 hours before exercising. Avoid alcohol and caffeinated drinks. They are diuretics which remove water from your body to increase the amount of urine the kidneys produce. Do remember that exercising when you are dehydrated will cause your body temperature to rise faster and your heart to work harder. Common effects of dehydration include headaches but serious conditions can bring about heat stroke. 

But how much water should you drink while working out? This of course depends on intensity and duration as well as the amount of perspiration. But drink before you thirst since thirst is an indication of dehydration. How much you need to drink at regular intervals during exercise and how much after exercise is best ascertained by body weight. Do this simple analysis. Weigh yourself before exercising but after passing urine and then again after exercising but before you pass urine. For every kilogram of bodyweight you lose, you should drink 1.5 litres of fluid. Should you exercise for less than an hour, water would be sufficient but for longer workouts, sports drinks containing carbohydrates are recommended or squash of some sort where sugar could give you an energy boost.

Replenishing your fluid after exercise is crucial. Besides refreshment it’s to also help your muscles recover. But don’t drink too much and it can be harmful and in extreme cases cause hyponatremia which dilute salts in your body causing your cells to swell. This is a dangerous medical condition. There are many types of sports drinks and a general understanding can go a long way. These normally contain carbohydrates and electrolytes such as sodium, potassium, magnesium and chloride. There are 3 main types of sports drinks and they are hypotonic, isotonic and hypertonic. So what’s the difference?

Hypotonic drinks contain less than 4g per 100ml of carbohydrates. Hence it’s low in carbs and has been designed to replace fluids you lose during exercise. Isotonic drinks however contain higher carbs which range between 4 – 8g per 100ml. Besides helping to replace fluids, they also help to replenish the body’s carb stores. This is important if you exercise for more than an hour. Hypertonic drinks have high carb content which is more than 8g per 100 ml. Your body absorbs it slowly and provide you with a real boost in refuelling. There is no magical ingredient in sports drinks and you too can prepare your own sports drinks. The table below provides a simple formula: