Do You Sweat When You Swim?

“No way I can sweat in the water,” you might think. However, if you ask any elite swimmer, they will certainly tell you they sweat in the pool. Is that true? Being involved in swimming for my whole life, I will speak both from experience and from the scientific standpoint about swimming and sweat. 

So, do you actually sweat when you swim? 

You can definitely sweat while swimming. Sweating is a biological function used by the body to cool itself down. That means, during high-intensity workouts, the body will break a sweat to cool down, even in the water. However, swimmers are less likely to notice the sweat because the water washes it off immediately.

Swimming and Sweat – Why Do We Sweat and How to Tell 

Sweating is a mechanism used by the body to cool itself under certain conditions. Basically, we sweat to keep our body temperature at a consistent rate. The human body doesn’t rely on elements outside of itself to regulate the temperature, so, when it gets hot, it sweats.

Swimming is a high-intensity workout, and high-intensity workouts cause the body temperature to skyrocket. When the body temperature increases, we begin the sometimes-stinky process of sweating. You might not notice the sweat since you are already surrounded by a lot of water, but trust me, it’s there.

While swimming, you will sweat less than other high-intensity activities on land. Most pools are kept at a temperature lower than the average body temperature (98.6º), so the water is actually helping your body cool down. But even though the water is helping to keep you cool, it does not stop the body from giving that natural response of sweating.

Being in the water may reduce the need for sweating, but it will not stop it entirely. However, if you are working out in a swimming pool that is above the average body temperature, you will sweat even more.

A3 Performance Tip: It is always important to hydrate during swim workouts, but it is even more important to stay hydrated while in hot pools. Make sure you are taking a couple sips of water every 5-10 minutes.

Also, if the swimmer is wearing a swim cap, they will sweat underneath the cap. The sweat will stay there, and they’ll lose even more electrolytes.

Out of the water, it is pretty easy to tell if you are sweating. However, in the water, it can be a bit tricky. Since we swimmers cannot rely on feeling sweaty, getting a dry mouth, or feeling hot, we have to rely on other methods to tell if we are sweating.

Breathing heavily is the most obvious sign that you are sweating in the water. It is one of the mechanisms the body uses to cool itself down to prevent overheating. So, if you are breathing hard and feeling winded, chances are you are sweating, too. Always make sure you are drinking an adequate amount of water!

It is important to note that swimmers can continue to sweat even after the workout is over. Elevated body temperature after swimming is the main reason for excessive sweating because it takes time for the body to cool off. Because water evaporation causes the body to cool down, whenever swimmers dry off the excessive water they can start sweating more than expected. It is completely normal, and sweating should stop soon after. 

Dangers of Dehydration in the Water and Performance Impact

While in the water, it can be difficult to notice dehydration. However, just because you don’t notice it doesn’t mean it’s not happening! Dehydration is dangerous and can have detrimental impacts on your body.

Dehydration occurs when your body is using up more fluids than taking in. This affects your body negatively because it stops the body from performing its normal functions. The signs of dehydration include thirst, irritability, headache, weakness, dizziness, cramps, and heartburn. Extreme dehydration can lead to vomiting, nausea, fainting, and eventually heat stroke.

Dehydration of just 1-2% of the body’s total weight begins to affect its ability to perform. When your body doesn’t have enough fluids, it causes your heart rate to spike, making your workout feel extra challenging. Dehydration is also common in hot, humid settings (like a pool deck), which is why it’s especially important to hydrate while swimming.

When we sweat, what exactly are we losing? Sweat is pretty much just water and tiny amounts of ammonia, salt, and sugar. When you sweat, you are also losing electrolytes. Electrolytes help our bodies to function correctly by keeping our Ph level balanced and regulated. They aid in building new tissue, helping the blood to clot, controlling muscle contractions, and regulating fluid levels. Hydration is especially important to maintain our levels of electrolytes.

With new sports drinks coming out every week, it can be hard to know what you should actually be drinking during your workouts. For most circumstances, water is the best solution for dehydration. It is completely natural and replenishes what your body is losing.

For particularly strenuous workouts in hot, humid settings, extra electrolytes may be beneficial. You can consume salt packets to maintain the electrolyte balance, or drink one of many sports drinks available on the market. However, the majority of people receive a sufficient amount of electrolytes in their regular diet and do not require any additional electrolytes.

If you are trying to lose weight, try to avoid sports drinks because they are high in calories and sugar and they will negate the calories you are burning through your workouts.

A3 Performance Tip: If you want the electrolytes without the calories, try mixing one-part Pedialyte with two-parts water. It will supply the electrolytes without the excess sugar and calories.     

To avoid dehydration, always have a water bottle with you before, during, and after workouts. The best athletes know they need to take regular sips of water throughout their workouts. Studies show that you should drink at least half a liter of water during your swim workout to avoid dehydration.

When exercising, hydration is your best friend. Water regulates the body temperature and lubricates the joints, allowing the body to perform at its highest level. It also improves muscle function and circulation while regulating blood pressure. Hydration is vital for Olympians, recreational swimmers, and everyone in-between.

A3 Performance Tip: If you are finding yourself extra sore or cramping after workouts, you probably aren’t drinking enough. Try drinking more water before, during, and after your swim.

Though it may sound weird, the best way to check if you are hydrated is by the color of your urine. The lighter the color, the more hydrated you are. So, next time you go to the bathroom, take a look to make sure you are drinking enough fluids. We promise not to judge. 

So, how much are swimmers actually sweating and how can they avoid the terrible consequences of dehydration? Read below –  we have all the information you need to stay active and healthy.

How Much Swimmers Actually Sweat

Now that we know swimmers are definitely sweating in the water, it’s a good question to ask how much they’re actually sweating. As I said earlier, they probably aren’t sweating as much as the average procurer of land sports, but it’s still a substantial amount.

A study done by the Australian Institute of Sport, found out just how much the average swimmer is sweating. The study was conducted on a group of elite Australian swimmers and the results showed the athletes lost an average of 125ml per every kilometer swam. That’s about 6.8 fluid ounces lost for every mile! While you’re swimming, your body is sweating out about a fourth of the average water bottle – that’s a lot of fluid!

Another study done by the School of Sport at Loughborough University, found that athletes sweat just shy of 800 ml in a 105-minute practice. These results are in perfect keeping with the previous study and prove swimmers are sweating a lot within the waves. Both studies also found female swimmers sweat less than male swimmers, which is relatively normal. Before puberty, boys and girls sweat pretty equally. Afterward, however, men start to sweat substantially more than women, and it’s no different in the pool.



The amount of sweat can vary due to environmental factors, such as the water temperature of the pool or the air temperature of the facility. Most pools designed for competitive swimming are kept at a temperature below the average body temperature to prevent swimmers from overheating. However, pools kept at temperatures above the average body temperature are going to cause the swimmer to sweat even more.

Additionally, if the pool is cold, but the air temperature of the facility is warm, it can also lead to additional fluid loss. Outdoor pools in warmer seasons or climates can be especially warm leading to more sweat.  

A3 Performance Tip: When training outside during the summer, pay extra attention to your fluid intake to make sure you are staying hydrated. Also, make sure to wear waterproof sunscreen because sunburns can cause additional dehydration.

Since swimmers don’t sweat as much, it’s an easy assumption to make that swimmers don’t face the same danger of dehydration as other athletes. However, this couldn’t be farther from the truth. In fact, swimmers can be even more susceptible to dehydration than other athletes simply because they don’t notice they are even sweating. It is essential to swimmers of all levels to remain hydrated while swimming to replenish the electrolytes and water lost during their workout.


Related Questions

Do swimmers sweat chlorine? Though a swimmer may smell like chlorine when the sweat, they are not actually sweating chlorine. During long water workouts, chlorine gets trapped in the pores of the skin. When a swimmer sweats, the pores open up, releasing sweat which picks up the chlorine on its way out of the pores causing the odor.

Is the pool full of sweat? The swimming pool is not full of sweat. The amount of sweat produced by the swimmers is very small in comparison to the gallons of water inside a pool. Plus, pools have chemicals in them to help regulate bodily fluids that end up in the pool.

How much water should a swimmer drink per day? Swimmers (like all other athletes) should try to drink half their body weight in ounces. So, a 140-pound person should aim to drink around 70 ounces of water a day. The more active you are, the more water you should consume, though. This is more of a baseline.


What tips or recommendations do you have for staying hydrated? Share them in the comments below! ⬇️ 

Be sure to look into our other articles On Deck too!

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September 11, 2020 — Roman Trussov


Kate Brownell said:

Good to know so much about swimming. I want to exercise but I am not happy to sweat excessively. I think water exercises will be very useful and I am using the anti sweat spray ( now so this has controlled sweating to a big extent. I just use it once in 5 days and the sweat is controlled. Thank you for sharing this post though. It really helped.

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