Do You Sweat When You Swim?

Michael Butler
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Swim and Sweat: The Performance Effects of Dehydration

Swimming is a popular recreational sport and form of exercise, along with running, biking, skating, and playing team sports. You can also make it competitive like the sport of open water swimming. Ever since people started wading in lakes and oceans, they have been swimming, but not until the 20th century did swimming become a competitive sport. Now there are Olympic and international swimming competitions.

For serious swimmers, training is an important part of their overall fitness regimen. This involves several key components, including technique (also known as freestyle), stroke mechanics, endurance, nutrition, hydration, recovery, and mental training.

One of the important elements of a training program is a person’s hydration levels. People who do not drink enough water are subject to dehydration effects that lead to fatigue and reduced performance. You can avoid this by drinking an adequate amount of water even during exercise so that you maintain hydration levels. It helps if you weigh yourself before and after a workout to learn your sweat rate, which is a measurement of how much fluid your body loses during exercise.

Water does not provide calories. If you’re doing endurance exercise, such as swimming, you may require about two cups of water for every hour of exercise. Planning your drinking strategy before, during, and after exercise can help you maintain the proper electrolyte balance in your body and improve performance.

How Much Do You Sweat When You Swim?

Swimming in the pool – or even just exercising in water – is a great form of exercise. Water doesn’t weigh you down like air, so it doesn’t require as much energy for you to move your arms and legs. And water’s resistance makes your body work harder, which is great for your muscles and joints.

But do you know that there are different levels of sweating, depending on what exercise you’re doing?

Many studies have shown that swimming in the pool can burn between 400 and 500 calories per hour. Typically, fitness swimmers will experience light sweating once they get acclimated to swimming in the pool. This means that they’ll be sweating lightly, so that they can still see their forehead through their perspiration.

Even though this level of sweating is less than that of someone who’s playing sports like tennis, racquetball, basketball or soccer, sweating during exercise is a good thing. Sweating means that you’re losing fluid from your body through evaporation. That’s a good thing; that means that your body is able to cool down while you exercise.

Study 1

“Swimsuits for Swimmers,” Journal of Exercise Physiology

To study the sweat factor in swimming, researchers tested the body temperature of swimmers wearing both swim caps (tops) and swimsuits (bottoms) in both warm and cool water. The subjects tested were 20 men and 20 women. The women in the study all wore swimsuits that came to just above the knee, while the men wore swimsuits that covered their upper legs.

The women who wore the knee-length suits sweated more than the women wearing the cap, and the men who wore the cap sweated less than the men wearing the knee-length swimsuits. The men in the cap and the women in the knee-length suit sweated about the same amount when swimming in the warm water.

Testing the “hot” water confirmed just how much of a difference the swimwear made. The men who weren’t wearing a cap sweated by about 40 percent less. While the women who weren’t wearing a suit sweated about 75 percent less.

When the female test subjects wore a swimsuit that covered their hips and male test subjects wore a cap, both genders sweated substantially less.

Study 2

Subjective and Objective Study to Determine Sweat Rates of Swimmers vs Other Groups

In the second study, conducted in the summer of 2015 by Jessica Bradley, a graduate student at the University of Wisconsin-Madison, 15 swimmers and 10 non-swimmers of similar age and fitness levels exercised on treadmills for 15 minutes at a low intensity (50-60% of peak heart rate). Eight research assistants wearing T-shirts and towels next to the treadmill measured sweat loss of all the participants.

The result? On average, the swimmers sweat 40% less than their non-swimmer and overweight counterparts. The researchers took body composition into account, but it did not seem to affect the outcome. This was an interesting finding, considering that by definition, swimming is an aerobic activity. In this sense, a greater sweat rate is necessary for optimal performance.

In another study, conducted at the University of Western Ontario in Canada by two sport and exercise biochemistry professors in 2005, 17 swimmers and 16 non-swimmers of similar age and fitness levels exercised on treadmills for 15 minutes at a low intensity. For this study, the results were measured using skin conductance level (SCL), a process that made the study more objective in its measurement of sweat rate.

The Takeaway

Swimming, along with cycling and running, is one of the most popular ways to get in shape. From celebrity millionaires to the average, everyday person, swimming is a favorite past time of many. However, what people don’t know is that it is one of the most strenuous exercise that you can do. Swimming, if you don’t do it right, is perhaps one of the hardest exercise to do.

That being said, though, just because you swim doesn’t mean you won’t get the same results as you would from doing, for example, cycling or jogging.

Generally, you can swim just about any angle except on your back. If you want to avoid the burning that can sometimes come with swimming upstream, however, it’s best to swim in an area where there are no currents. Also, swim in a pool with warm water and use your legs to do the pumping. That will also help you avoid neck issues.

With the information about how to swim right, you can continue to swim without having to worry about pulling muscles or straining your neck by kayaking enough.