From a runner’s perspective, staying adequately hydrated is important for two reasons. First, it’s critical to reaching one’s performance potential. Second, it’s the key to avoiding certain running-related health risks such as muscle cramping and heatstroke. It’s easy to stay properly hydrated, but many people forget that hydrating is important before, during, and after a treadmill workout.
Hydrating Before a Workout
Hydrating for a long run (longer than eight miles or so) actually requires a few days of preparation. For a few days before your run, drink plenty of water – enough that you feel the call of nature at least six times a day. Also, avoid alcoholic beverages and even caffeinated beverages if possible; these dehydrate the body.
An hour before the run, drink about two to three cups (16 to 24 ounces) of water or an appropriate non-caffeinated sports beverage. Immediately before running, drink another few ounces or up to one cup.
Drinking on the Go
Generally speaking, a person needs to take in 4-6 ounces of fluid per 20 minutes of running. The longer the run, the more important it becomes that electrolytes are balanced with the aid of a sports drink; water isn’t enough after 90 minutes or so.
Hydrating After the Run
It’s important to rehydrate right after a run. About 20-24 ounces of fluid (water or a sports drink) should be taken in for each pound lost.
Account for Individual Differences
Keep in mind that the fluid recommendations above are only guidelines. For one thing, some people sweat more than others. You might also have different hydration needs when using a treadmill compared to when running outside. For example, your body might be cooled more easily outdoors than indoors because of the natural breeze – or it might heat up quickly because of the sunshine.
To know your exact fluid requirements, approach the issue scientifically: weigh yourself before and after a treadmill run to determine how many of ounces of water you lose per hour.