TOP TIPS Make sure you start your run fully hydrated. If you are setting off in the morning, try and have at least 500 ml of fluid from waking to the start. Drink so that your urine is straw coloured. Your body will always try to keep the levels of sugars and salts in your cellular fluid balanced. Just drinking water stimulates your kidneys to produce more urine to keep the concentrations of sugars and salts the same. This means it takes longer for you to rehydrate properly. Using an electrolyte drink such as GO Hydro helps with fluid retention as it provides the optimal dose of sodium, at a concentration of 300 mg per 500 ml of fluid. Take something to drink or plan your route so that you can stash a bottle and loop past it during your run if you are going out for longer than an hour in the heat. Use GO Electrolyte in your hydration pack or bottle for runs longer than 90 minutes in duration, to meet both energy and hydration demands. Drink 500-1000ml per hour. How much you need depends on your sweat rate and how hard you are working. You may be more comfortable avoiding lunchtime runs and switching your training to the morning or late evening if you prefer to run in cooler temperatures. If you are racing or training abroad, try and arrive at least 3 days early to give yourself time to acclimatise. Don’t get frustrated and push yourself too hard if you cannot match your normal pace in the heat. This is a normal physiological response to heat stress. You will find that your heart rate will be higher at a given pace in hotter conditions. Make sure you cover up to stop you from burning your skin. Vests are cooler but a breathable top with short sleeves protects your back and shoulders. Think about suncream and a hat if you’re likely to burn your head. Written By Ted Munson (Performance Nutritionist) Ted is a Performance Nutritionist here at Science in Sport.