Physiologically water keeps your body from overheating. When you exercise your muscles generate heat. To keep from overheating your body discards this heat by sweating. The sweat cools down tissues beneath the skin. But when you sweat then you lose fluids that you need to transport the heat. Hence, the need to replace this fluid. And if you don’t not only are you not cooling yourself but your using fluid that is needed to assist other body functions. Including your heart and kidneys. This isn’t anything to play with.
So how much? According to the American College of Sports Medicine (ACSM) to avoid dehydration active people should drink 16-20 ounces of fluid 1 to 2 hours before your outdoor activity. And then 6 to 12 ounces every 15 minutes while you’re outside. When you’re finished, another 16-24 ounces.
Are some type of beverages better than others?
Water is the standard. But if you’re going to be grinding for an hour or more you may want to consider a drink that also has some sodium and potassium added. These add-ons can help you to avoid muscle cramping which occurs when you have a deficiency in electrolytes.
Oh, and don’t be fooling yourself if by thinking that just because they’re wet that coffee, sodas or teas are going to hydrate you. In fact quite the opposite. These drinks pull water from your body which results again in…….DEHYDRATION.
If you’re a runner you would be interested to know that a recent study conducted at the University of North Alabama demonstrated even further the benefits of hydration for the competitive runner. Researchers had 13 runners run a 75 minute evening run which was followed the next morning by a 10k time trial. After one of the evening runs the runners rehydrated 75% of the sweat they lost. After the next evening run the runners rehydrated with 150% of what they lost through sweat. The runners who replaced 150% were on average over a minute faster than when they replaced with 75%. In marathon terms this can be the difference between a 4:00 and 3:52 finish.
To determine how much you have lost during a run do this. Weigh yourself before you run and then right after. The ACSM recommends taking in 16 to 24 ounces of fluid for each pound lost. So if you lose 4 pounds during your run then multiply that 4 by 16 = 64 ounces, then 4 x 24 = 96 ounces. Your replacement amount should then be 64 to 96 ounces that day, or at least 4 – 20 ounces bottles of fluid.
A word of warning. A lot of “fluid replacement” drinks boast about their effects when in fact they’re just drinks with high sugar levels. Make sure these drinks also have potassium and sodium in them. Otherwise stick to straight water if it’s unclear what is in your container. I typically take water with me and if it has been an unusually hard run will then look for an electrolyte replacement afterwards. Lately I’ve been using tablets mixed with water in order to avoid the other additives that get thrown in. How about you? Do you have a “go to” drink that you use?