Why Does Our Skin Smell Different After Exercise?

Skin & Wellness Magazine

There are days when we finish a workout, feel great, and then comes the moment when we raise an arm or change our shirt and discover that our body has other plans.

Sometimes the smell is barely noticeable, even after an intense workout. At other times, precisely after a short walk or moderate activity, we feel a stronger smell than usual.

How can it be that the same woman, with the same deodorant and the same hygiene habits, smells different from workout to workout?

The answer lies in the combination of the sweat, the bacteria living on the skin, the type of clothes we wear and even what we ate before the workout.

Our sweat is not really responsible for most of the smell

When we exercise, the body's temperature rises. To cool us, the sweat glands secrete a fluid that reaches the skin's surface and evaporates.

Most of the sweat created during physical activity comes from eccrine glands, and it is composed mainly of water and salts.

This sweat, when it is secreted, usually has no strong smell.

So where does the smell come from?

On our skin live bacteria that break down substances found in the body's secretions. During the breakdown, volatile substances are created, some with a characteristic smell.

In the armpits, for example, apocrine glands also operate. Their secretions contain components that skin bacteria can turn into compounds with a stronger smell.

In other words, the smell we smell after a workout is not only a result of the amount of sweat, but also of what happens when it meets the skin environment.

The skin microbiome — a whole world we do not see

On our skin live billions of microorganisms, among them different types of bacteria.

This population is called the skin microbiome.

Not all of these bacteria are harmful. Many of them are a natural part of the system that helps maintain a balanced skin environment.

But different bacteria have the ability to break down different substances, and therefore also to produce different smells.

In the armpit area, for example, certain bacteria from the corynebacterium group are connected to creating some of the compounds responsible for body odor.

The bacterial composition varies from person to person and is influenced by genetics, hormones, skincare products, hygiene and the environment.

This is one of the reasons why two women doing exactly the same workout will not necessarily smell the same after it.

Why do we sometimes sweat a lot and barely smell?

The amount of sweat and the strength of the smell are not necessarily connected to each other.

It is possible to sweat a great deal during a workout and feel only a slight smell, and it is possible to sweat relatively little and still notice a strong smell.

The reason is that the smell depends on the composition of the secretions, on the bacteria's activity and on the conditions on the skin's surface.

The time that passes until we change clothes or shower also matters.

The longer the moisture stays on the skin and in the clothes, the more opportunity there is for smelly substances to accumulate.

Does the type of workout change body odor?

The type of activity can affect the amount of sweat and the conditions in which it is created.

In prolonged aerobic training the body produces a lot of heat, so we may sweat more.

In strength training, in contrast, sweating can vary according to the intensity, the workout's duration and the room temperature.

Activity in a heated room or a humid environment can also cause more sweat to accumulate on the skin.

But there is no evidence that each type of workout has a unique and fixed body odor.

What matters is mainly the combination of sweat-gland activity, the skin environment and the clothes.

And what about training on an empty stomach?

This is a particularly interesting question.

When we are in a prolonged fast or consume very few carbohydrates, the body may produce more ketone bodies as part of using fat as an energy source.

One of the substances created in the process is acetone, which can be released through the breath and sometimes also through the skin.

It may create a slightly fruity smell or a smell reminiscent of nail-polish remover.

But it is important to distinguish between a ketone smell and the regular sweat smell created by skin-bacteria activity.

Not everyone who trains on an empty stomach will develop such a smell, and it is impossible to conclude from body odor how much fat we burned during the workout.

Does what we eat before the workout affect it?

Sometimes yes.

Foods such as garlic, onion and certain spices contain substances that can undergo breakdown processes in the body, and some of their breakdown products may be secreted through the sweat or the breath.

Alcohol can also affect body odor.

But there is no need to start avoiding healthy foods just because of the fear of smell during physical activity.

In most cases these are temporary effects, and they differ from person to person.

Why do sportswear smell even after washing?

I think almost everyone who exercises regularly knows this phenomenon.

We take a clean sports shirt out of the machine. It smells great. But after a few minutes of training, the old smell returns.

The reason is connected, among other things, to the type of fabric.

Certain synthetic fabrics, such as polyester, tend to hold on to fats and smelly substances more than other fabrics.

Bacteria residues and body substances can also remain inside the fabric fibers, especially if the wash does not remove them well.

When the garment heats up and becomes moist again, the smell may be felt anew.

This is not necessarily a problem with our skin.

Sometimes the source of the smell is precisely the shirt.

How can we prevent smell that stays in sportswear?

A few simple habits can help:

• Do not leave wet sportswear inside a closed bag for hours.
• Allow the clothes to dry if they cannot be washed immediately.
• Use an appropriate amount of laundry detergent, without overloading.
• Check the garment's washing instructions and use the permitted temperature.
• Avoid excess fabric softener, which may leave a layer on some fabrics and harm their ability to wick moisture.
• Choose fabrics suited to the type of activity and our sweating level.

Sometimes changing the sports shirt does more than any change of deodorant.

Do we need to shower immediately after every workout?

Not necessarily in the same second, but it is worth not leaving wet clothes on the body for a long time.

A shower after physical activity helps remove sweat, fats, dirt and product residues from the skin.

If it is not possible to shower immediately, you can change into dry clothes and gently clean areas where sweat accumulates.

It is also important to remember that there is no need to scrub the skin forcefully or use an aggressive soap to feel clean.

Excessive washing can cause dryness and irritation, especially in those with sensitive skin.

Is natural deodorant as effective as antiperspirant?

It depends on the product and on our goal.

Deodorant is mainly intended to reduce or mask smell, and sometimes contains ingredients that limit the activity of the bacteria responsible for the smell.

Antiperspirant, in contrast, reduces the amount of sweat that reaches the skin's surface, usually by means of aluminum salts.

If the problem is mainly smell, a suitable deodorant may be enough.

If there is also significant sweating, an antiperspirant can be more effective.

The word “natural” does not promise that a product will be more effective or gentler. Plant ingredients, essential oils and baking soda can also cause irritation in some people.

Does sweating help the body get rid of toxins?

This is one of the most common myths in the world of health and fitness.

Although small amounts of various substances can be found in sweat, its main role is regulating body temperature.

The liver and kidneys are the central organs responsible for processing and removing many substances from the body.

Therefore, much sweating is not a measure of toxin cleansing, and a workout in which we sweated more is not necessarily healthier or more effective than a workout in which we sweated less.

When does a change in smell after a workout require attention?

If the smell changes slightly according to the type of workout, the clothes or the diet, there is usually no reason for concern.

But a new, strong and persistent change in body odor, especially if accompanied by additional symptoms, can justify a medical investigation.

An unusual fruity smell from the breath that appears together with extreme thirst, nausea, vomiting or rapid breathing may be a sign of an urgent medical condition, especially in people with diabetes.

Unusual sweating, fever, unexplained weight loss or a significant change in the health state also justify an examination.

And to finish — not every smell after a workout is a sign of something wrong

I love the feeling after physical activity. The body worked, the muscles were activated, and we feel we did something good for ourselves.

But the sweat that accompanies this activity is not always pleasant, especially when it leaves a smell on the skin or the clothes.

In my eyes, the important thing is to understand that body odor does not necessarily indicate a lack of cleanliness.

It is the result of natural processes occurring on our skin, in combination with the bacteria living on it and the environment we are in.

Sometimes the solution is a shower, sometimes changing a garment, and sometimes simply choosing a product that suits us better.

Because sweating is a natural part of the body's activity, and the smell that appears after it is not always something to fight — but something worth understanding.

Skin & Wellness Magazine | OrOrgani

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