While it’s important to stay hydrated during exercise, it’s impossible to create one-size-fits-all drinking guidelines. Your weight, sweat rate and effort level, and the temperature, all affect how much you should drink. But that doesn’t mean you should leave your hydration plan to chance. These strategies can help ensure you drink the right amount before, during and after every run.
Before your run
One of the best ways to limit dehydration during a run is to drink enough beforehand. ‘Checking your urine pre-run is an easy way to see if you’re hydrated,’ says Dr Lewis Maharam, former medical director of the Rock ’n’ Roll race series. ‘If it’s the colour of iced tea, you need to drink more. If it’s a pale lemonade or straw colour, you’re nicely hydrated.’ With the exception of alcoholic drinks, which are dehydrating, all beverages, including water, sports drinks, coffee, tea, juice and milk, can help keep you hydrated throughout the day.
During your run
If you’re out for an 18-miler, drinking mid-run is a no-brainer. But what if you’re going for an hour? Or doing intervals? ‘There have been a range of recommendations over the past two decades,’ says Maharam. ‘The newest brings us back to basics: drink to your thirst.’ It’s advice backed up by the International Marathon Medical Directors Association and Dr Tim Noakes, author of Waterlogged: The Serious Problem of Overhydration in Endurance Sports (£16.99, Human Kinetics). ‘Your thirst mechanism is exquisitely tuned to your body,’ says Noakes. ‘If you drink when you’re thirsty, you’ll keep your body adequately hydrated.’
The American College of Sports Medicine recommends drinking enough so you don’t lose more than three per cent of your weight through sweat – lose more than that and your performance starts to falter. One way to figure out how much you lose during an hour of running is to weigh yourself naked pre- and post-run (without drinking anything during the run). The number of kilograms you lose equates to your sweat loss in litres. So, if you lost a kilo, you sweated a litre of fluid. On runs longer than 60 minutes, sports drinks are a good idea. They have carbs for energy, and electrolytes such as sodium and potassium, which are lost through sweat but are integral to nerve and muscle function.
After your run
When you come in from a run, drink until you’re satisfied. If your face has white salt streaks on it post-run, it means you’ve lost quite a bit of sodium, so it’s best to have a sports drink, water with an electrolyte tablet in it, or water along with food that contains sodium. After especially long or hard runs, you also need protein to help your muscles heal. That’s why recovery drinks are ideal – they provide protein and fluid to help you rehydrate. ‘Chocolate milk is a great choice,’ says Maharam. ‘The carbs-to-protein ratio is perfect for recovery.’