Pimples on the Buttocks and Exercise: Why They Appear and How to Prevent Them

You’ve started running, biking, or working out at the gym again, and ever since, small red bumps have been appearing on your buttocks. This isn’t a coincidence: exercise brings together everything that irritates the skin in that area—sweat, heat, constant friction, tight synthetic clothing, and often damp workout clothes that you keep on for another hour after your workout.

That doesn't mean you have to stop exercising, though. In most cases, all you need to do is make a few changes to your pre- and post-workout routine and adopt a gentle daily skincare regimen. As part of your routine, a lactic acid-based anti-blemish body treatment helps the skin renew itself and prevents pores from becoming clogged. Here's how to understand what's happening and how to get rid of it.

Why Exercise Causes Pimples on Your Buttocks

Exercise itself is great for the skin: it boosts circulation and helps manage stress. The problem lies in what comes with it. On the buttocks, four factors come into play during and after exercise.

• Sweat: When sweat mixes with sebum and dead skin cells, it can clog pores and hair follicles.
• Heat: A warm, moist environment is ideal for the growth of bacteria and yeast that are naturally present on the skin.
• Friction: Tight leggings, a bike seat, or a weight bench create constant friction that irritates the skin and damages the hydrolipidic film, its protective barrier.
• Maceration: Keeping your clothes damp after a workout means letting your skin soak in sweat. This is often the most underestimated factor.

The result: inflammation of the hair follicles, known as folliculitis. It manifests as small red bumps, sometimes with a white head, that may itch or be slightly painful. Therefore, it is generally not acne in the strict sense, even though it looks similar. For other possible causes, see the causes of bumps on the buttocks.

The sports most affected

All sports can contribute to the development of acne, but some involve more risk factors than others.

• Cycling and spinning: prolonged pressure on the saddle, heat, friction, and sweat all in the same area. This is a classic example.
• Running: tight synthetic leggings, profuse sweating, and an outfit often kept on for the trip home.
• The gym and fitness area: shared benches and mats, repeated sitting positions, tight-fitting clothing.
• Swimming: Chlorine dries out and irritates the skin, and wearing a wet swimsuit after a swim contributes to maceration.
• Combat sports and hot yoga: contact with the mats, the heat in the room, form-fitting clothing.

Identify the type of button

Before treating something, it's best to know what you're dealing with.

• Small red bumps centered around a hair, sometimes with a white dot: this is folliculitis, the most common cause among athletes. It is usually caused by bacteria, but it can also be fungal in very hot and humid environments.
• Very small, itchy red bumps that appear during or right after exercise: these are often heat rash, caused by sweat that can’t escape. Everything you need to know about heat rash on the buttocks.
• A large, red, hot, and painful bump: this is often a boil, a deeper infection of the hair follicle. Keep a close eye on it: see “painful bump on the buttock.”
• A red bump with a hair under the skin: this is an ingrown hair, which is common if you remove hair and friction prevents the hair from growing out.
• Grainy skin with small, rough bumps, without redness or pain: it’s not from exercise; it’s probably keratosis pilaris. It often affects the backs of the arms as well and tends to get worse in the winter.

Before the session: Prepare your skin and choose your outfit

• Appropriate clothing: breathable, performance-oriented fabrics that wick away sweat, rather than low-quality synthetics that trap it. Wear cotton or breathable underwear under your leggings—never underwear that’s already damp.
• Not too tight: Compression clothing can be helpful, but if it leaves marks on the skin, it will chafe.
• Clean, clear skin: Avoid applying thick or greasy lotions right before exercising, as they may clog your pores when exposed to heat.
• A clean towel on the benches and machines in the gym.
• Don't shave the day before: a hair follicle that's just been shaved, combined with sweat and friction, is a surefire recipe for irritation. Wait 24 to 48 hours.

After the session: the 30 minutes that matter

That's where it all comes down to. The golden rule: never let your butt sit in damp clothes.

• Change immediately: Take off your wet workout clothes as soon as your workout is over, even if you can't shower right away. Always keep a dry pair of underwear in your bag.
• Take a quick shower with lukewarm water rather than hot water, which dries out the skin and contributes to inflammation.
• Gently cleanse: Use a mild soap or fragrance-free cleansing gel, applied by hand, without a glove or sponge, which could irritate the skin.
• Dry thoroughly by patting with a clean towel—without rubbing—paying special attention to the buttock crease, where moisture tends to linger.
• Lightly moisturize with a non-comedogenic product: well-hydrated skin is better able to protect itself. Tips for moisturizing your skin right after a workout.
• Wash your workout clothes after each use: wearing leggings twice without washing them brings bacteria back into contact with your skin.

A Daily Routine to Get Rid of It

If you already have pimples, a gentle, consistent routine will take care of most cases. Wait two to four weeks before judging the results: skin renewal takes time.

1. Clean without stripping

A gentle cleanser, once or twice a day depending on how often you work out. Antiseptic soaps used daily destroy the hydrolipidic film and disrupt the skin’s natural flora, causing the skin to become more reactive. More tips for properly cleansing acne-prone skin.

2. Exfoliate with active ingredients rather than with granules

Exfoliation removes dead skin cells that clog follicles. On inflamed skin, exfoliating ingredients are more effective and gentler than a coarse-grained scrub. Salicylic acid penetrates the pores and soothes inflammation; lactic acid refines the skin’s surface while hydrating it. This is the principle behind Fesse Time, the lactic acid body treatment formulated for the skin on the buttocks: apply once a day to clean, dry skin. As a complement, use a gentle sugar scrub once a week on areas without inflamed breakouts: see how to gently exfoliate the skin.

3. Target inflammatory pimples

For more severe breakouts, benzoyl peroxide cleansing gel is a go-to antibacterial treatment: apply it for a few minutes in the shower before rinsing. It can dry out sensitive skin and discolor fabrics, including towels. For a natural option, tea tree essential oil—always diluted in a vegetable oil—can be applied topically to an isolated pimple.

4. Moisturize, even if you have pimples

Dehydrated skin compensates by producing more sebum and thickens, which traps hair and clogs pores. Light moisturizing every day keeps the skin supple and soft.

5. Let your skin breathe every day

Even outside of sports: wear cotton underwear, pants that aren't too tight, and avoid sitting for hours on end whenever possible. In the summer, the heat makes everything worse.

Mistakes That Cause Acne

• Leaving your workout clothes on after your session—whether for the commute or a coffee—is a surefire way to let them get smelly.
• Popping or scratching pimples: the inflammation spreads deeper, the risk of infection increases, and the lesion may leave a mark or a scar.
• Scrubbing hard with a horsehair glove: micro-injuries make the inflammation worse instead of soothing it.
• Inappropriate hygiene: too little (sweat left on the skin) or too much (harsh soaps used several times a day) leads to the same result—irritated skin.
• Rich creams or comedogenic oils applied right before exercise, which trap heat and clog pores.
• Don't overdo it: Layering multiple acne treatments can irritate your skin. A gentle cleanser, an active ingredient, and a moisturizer—that's all you need.

Other factors to keep in mind

Exercise is often the trigger, but it isn’t the only factor. Oily or acne-prone skin, especially when there are pimples on the face or back (bacne), will react more quickly. Hormonal factors—particularly around menstruation or during pregnancy—as well as stress and an unbalanced diet can also affect the skin’s balance. Whether for adults or children who play sports, the best practices remain the same.

When to Seek Medical Attention

Sports-related rashes are generally harmless. You should see a doctor or dermatologist if:

• a bump becomes painful, warm, swollen, or develops into a pus-filled sore;
• the redness spreads or is accompanied by a fever;
• the pimples persist after a month of following a proper skincare routine, or keep coming back;
• They leave scars or marks.

A healthcare professional can identify the exact cause (bacterial, fungal, acne, or another skin condition) and recommend an appropriate treatment: a topical antibiotic, an antifungal medication, or a more targeted treatment. In cases of recurrent hair-related folliculitis, the professional may also suggest laser hair removal.

FAQ

This article is published for informational purposes only; it is not a substitute for medical advice.