Exercise produces a lot more than just endorphins. It also triggers a waterfall of sweat when you're crushing your early morning indoor cycling class or maxing out the plates on leg day.
But it's not just the puddles of water surrounding your bike that tend to gross you (and other people out). It's also the odor that seems to escape out of every pore of your body that leaves you asking, "Why do I smell so bad when I work out?"
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What's That Smell?
Contrary to what you may think, it's not your actual sweat that smells bad. Yep, you could produce buckets of perspiration and not smell (if you're lucky). Rather, the stink comes from bacteria that naturally live on your skin breaking down the sweat.
"The bacteria located on your skin — there are bacteria everywhere on and in one's body — 'eat' the components of sweat," explains Susan Besser, MD, family medicine expert with Mercy Personal Physicians at Overlea.
That's because sweat contains, among other things, fatty acids and skin cells that your body sheds. When the bacteria go to town, they degrade these components, causing an odor in the process as they are "digesting" the sweat. (Lovely.)
Your body might make more of those odor-producing compounds when you're exercising, says Richard Torbeck, MD, board-certified dermatologist with Advanced Dermatology PC. "When you work out, you can produce cortisol and [other] hormones that affect the sweat glands on our skin," he explains. Sweat glands in the armpits, groin and other classically smelly areas, called apocrine glands, produce what Dr. Torbeck says are believed to be a pheromone-like substance that provide energy for skin bacteria and are behind your unfortunate aroma, he says.
Sweat in other areas is produced in what's called the eccrine glands, and it doesn't cause the intense odor that originates from apocrine glands. Eccrine glands are located all over your body, and they mostly help regulate your body temp.
Read more: Ew! Why Do I Sweat So Much When I Work Out?
What to Do About Your Smelly Sweat
You may not be able to totally eradicate the odors that creep out of your body when you work out (sorry), but you can take some preventive measures to at least rein in the stink a little. Here's what to try.
This probably goes without saying, but scrubbing your smelly spots with soap is your first line of defense in controlling body odor after exercising. As tempting as it may be just to strip off your workout clothes and jump into some clean ones, washing off your body — especially the areas that seem to produce the smelliest sweat — will for sure make a difference.
"If you can clear your skin of [dead skin cells] and keep your skin healthy and clean, that will reduce the smell," Dr. Besser says. Bonus points if you can squeeze in a quick shower as soon as possible after your workout.
Benzoyl peroxide body washes up the ante when regular soap isn't pulling its weight, Dr. Torbeck says. "By washing [smelly] areas with antibacterial washes, you reduce the odor-causing bacteria," he explains.
Take Underarm Precautions
The next time you're in the deodorant aisle, make sure you look for products that can help control body odor. Options with both antiperspirant and deodorant effects might be worth trying if your workouts have been smelling extra stinky lately. Dr. Besser recommends a professional-strength pick like Drysol, which, she says, can help reduce the amount of sweat your pits produce.
Wear the Right Clothes
The best clothes for working out and minimizing that sweaty smell has to do with the material or fabrics listed on the label. Choose natural fabrics such as cotton that are also moisture-wicking and breathable. That way, your gear allows your body to breathe instead of trapping sweat.
Consider Professional Treatments
If you've adopted healthy hygiene habits and exhausted your over-the-counter options, it might be worth talking to a dermatologist about what to try next for your stinky situation. Prescription topical treatments like clindamycin, erythromycin and azelaic acid can reduce odor, Dr. Torbeck says.
If all else fails, he adds, you may want to consider an in-office treatment that reduces the sweat you produce overall like Botox or miraDry. Look for an American Academy of Dermatology board-certified doc to walk you through your options.
Check Your Diet
What goes in must come out, right? Turns out that's the case for sweat, too. If the foul scent seems to show up right when you're finishing your workout, you might want to try cutting back on certain smelly foods. According to the Mayo Clinic, some spicy or strong-smelling foods and caffeinated beverages may increase your sweat output and risk of body odor. A handful of the more common culprits include onions, garlic, asparagus and cauliflower. Some people may also find their sweat particularly noticeable while exercising after a night of drinking alcohol.
Read more: The Top 10 Calorie-Burning Cardio Workouts to Try
When to See a Doctor
There are certain red flags with smelly sweat that may warrant a visit to the doctor's office. For example, if your scent suddenly changes, it could be a sign of an underlying metabolic disorder like diabetes, Dr. Besser says.
It's not common, but a genetic condition called trimethylaminuria (sometimes called fish odor syndrome for the smell it gives off) could potentially be to blame, Dr. Torbeck says. The condition involves an inability to break down certain compounds in the body; modifying your diet with the help of a health care professional to avoid foods that contain these compounds or their precursors may help reduce the odor.
For the most part, though, your smells are completely normal — just keep that deodorant on hand.
- Actas Dermosifiliogr: "Microwave Treatment for Axillary Hyperhidrosis and Bromhidrosis."
- Mercy Medical Center, Dr. Susan Besser, MD: "Personal interview"
- Advanced Dermatology, Dr. Richard Torbeck:"Personal interview"
- The Mayo Clinic: "Sweating and Body Odor"
- Genetics Home Reference: "Trimethylaminuria"