What is Sweat Rate

If you are an athlete or find yourself hitting the gym a couple times a week, you may have heard the term “sweat rate” tossed around – particularly if you work with a personal trainer. While most common among marathoners, joggers, and runners, sweat rate applies to all forms of exercise, and is key to ensuring your body stays properly hydrated before, during, and after a good work out. Keep reading to learn more about this important hydration technique.

What is Sweat Rate?

In simple terms, sweat rate is the amount of sweat your body excretes during exercise. As you work out, your body’s internal temperature increases. This higher level of body heat can adversely affect internal organs. Fortunately for us, the body is pretty clever, and uses the water in our body as a way to transfer this heat (and impurities) away from our organs and to the surface of the skin, keeping us cool and safe.

Of course, this water (and electrolytes as well) need to be replenished for the body to continue functioning properly, which is one of the reasons why we stress the need for proper hydration so much.

But the question arises – is there a way to be too hydrated? How much water is enough? How much is too much?

The body’s water system is a delicate balance – if you lose to much water, you begin to suffer the effect of dehydration, which ranges from thirst and dark colored urine to dizziness, confusion, and in the worst cases, death. These symptoms begin occurring after you lose between 1-2 percent of the water in your body. If that number goes up to 3-4 percent, you can find yourself in serious trouble. This is particularly alarming if you consider the fact that most people on the planet are always in a minor state of dehydration. In fact, are you thirsty right now? If so, you are already dehydrated!

Too much water in the system is not good either, though overdosing is not as likely as dehydration. So how do we know how much water to drink, especially if we workout?

The Sweat Rate Test

Determining your sweat rate – the amount of liquid you lose during a workout – is fairly simple. First, strip off your clothes and weigh yourself, prior to any exercise. Take note of your weight. Next, exercise for an hour – hopefully with your close back on! If you take any sips of water or other liquid, note the amount of ounces you consume.

Next, dry off any sweat on your body and weigh yourself in the nude again. Now subtract your pre-workout weight from your after-workout weight. After that, convert the amount of weight you lost to ounces (16 ounces equals a pound) and add the amount of water you drank to that number.

So let’s say you weigh two pounds less after the workout and drank 8 ounces of water during your routine. Two pounds is 32 ounces (2×16) plus the 8 ounces of water you drank is a total of 40 ounces.

This means you lost a total of 40 ounces of liquid while working out. Now the tricky part is determining how much water your body needs to stay hydrated during your workout. To do that, divide the number of fluid ounces you lost by 4. This is the amount of water you should be drinking every fifteen minutes in order to stay properly hydrated. In our example, you would need to drink 10 ounces of water ever 15 minutes to make up the liquid you lost to sweat.

Because your environment and types of workout you partake in can vary, you should perform this test several times, under different conditions, to find a mean sweat rate level.

At the end of the day, proper hydration is a simple task, so long as we make it part of our daily goal. Being sure to drink a glass of water before any meal, when you wake in the morning, when you go to bed at night, and whenever you are thirsty are all great techniques to practice. Eating fruits and vegetables with high water content is also beneficial.