Acne and fitness - causes and solutions

12 min read

You start strength training, you see results, you feel good - and then pimples appear on your forehead, shoulders, or back. Sound familiar? You're not alone. Many people who start intensive sports notice changes in their skin. But before you hang up your running shoes: training itself is rarely the direct cause of acne. The real culprits are more subtle.

What is acne actually?

Acne occurs when sebaceous glands in your skin produce too much sebum. That sebum, combined with dead skin cells, clogs your pores. Bacteria that naturally live on your skin (particularly Cutibacterium acnes) then get free rein and cause an inflammatory reaction. The result: pimples, blackheads, and in severe cases cysts.

There are multiple factors that accelerate this process: hormones, nutrition, stress, sleep deprivation, and - relevant for athletes - sweat, friction, and certain supplements. The good news: you can influence most of these factors.

The role of sweat and hygiene

Sweat itself does not cause acne. It is a mix of water and salts that your skin actually tolerates quite well. But sweat that remains on your skin for a long time, combined with tight sportswear, creates a warm and humid environment in which bacteria thrive.

Additionally, there is the problem of equipment hygiene. Benches, handles, mats - everything in the gym is touched by dozens of people per day. If you then touch your face with those hands (and most people do this unconsciously dozens of times per workout), you transfer bacteria to your skin.

What helps: shower as soon as possible after your workout. Use a mild facial cleanser (no aggressive scrub). Wear breathable sportswear made of synthetic material that wicks away moisture. Wipe equipment before use and try consciously not to touch your face during training.

Testosterone and hormones

A common story: strength training increases your testosterone, and testosterone causes acne. This is partially true, but the nuance is important. Strength training does temporarily increase your testosterone, but the rise is modest and returns to baseline within a few hours. This natural fluctuation is too small to cause significant acne.

A completely different story is the use of anabolic steroids or prohormones. These cause a significant increase in androgenic hormones, which drastically increases sebum production. Steroid acne is a known and well-documented side effect, especially on the back and shoulders.

In women, the menstrual cycle can influence acne. Around ovulation and before menstruation, there is a natural increase in androgenic hormones. If you also train intensively during that phase, it can put extra strain on the skin.

Nutrition and supplements

This is where it gets interesting for athletes. Multiple studies show a connection between whey protein and acne. Whey stimulates the production of IGF-1 (insulin-like growth factor 1), a hormone that increases sebum production. Not everyone is equally sensitive, but if your acne gets worse after starting whey, it's worth switching to a plant-based alternative (pea, rice, soy) for a month to see if it makes a difference.

Other nutritional factors that can play a role:

• Dairy in general - not only whey, but also milk and yogurt can worsen acne in some people via the IGF-1 mechanism
• High glycemic food - food that makes your blood sugar rise quickly (white bread, sugar, candy) increases insulin, which indirectly stimulates sebum production
• Supplements with high doses of B12 or biotin - both can worsen acne in sensitive individuals
• An extreme bulk - a significant calorie surplus structurally increases your insulin levels, which can trigger acne

Practical approach for athletes

The solution is not to stop training. Training is actually good for your skin in the long term: it improves circulation, lowers stress hormones, and supports a healthy hormonal profile. The solution lies in your habits around it.

An effective routine for acne-prone athletes:

• Shower within 30 minutes after training with a mild cleanser
• Use a light, non-comedogenic moisturizer after showering
• Wash your sportswear after every workout (sounds logical, but many people wear the same workout pants multiple times)
• Switch whey for plant-based protein if you have acne and see if it improves after 4-6 weeks
• Keep your bedding clean - especially your pillowcase, change it at least twice a week
• Avoid touching your face during training

When to see a dermatologist

If you still suffer from persistent acne after adjusting the above habits, it is wise to visit a dermatologist. Severe acne can cause scarring if left untreated. A dermatologist can prescribe targeted treatments, from topical agents to oral medication in some cases.

Always report which supplements you use and how intensively you train. This helps the dermatologist choose the right treatment.

Common mistakes

• Stopping training because of acne - the cause is almost never the training itself, but the factors around it
• Using aggressive skincare (alcohol-based toners, harsh scrubs) that irritate your skin and actually worsen the acne
• Washing your face multiple times every day - twice a day is enough, more often dries out your skin causing your sebaceous glands to actually produce more
• Continuing to take supplements blindly without testing if they are the cause

Acne mechanica: sport-specific

Besides hormonal and nutrition-related causes, there is a third category that specifically affects athletes: acne mechanica. This type of acne is caused by pressure, friction, and heat on the skin. Think of a helmet when cycling, a shoulder brace during strength training, a backpack when hiking, or even the neckband of your hoodie when running.

The combination of sweat, friction, and heat creates the perfect conditions for clogged pores and inflammation. This explains why athletes often have acne in places where clothing fits tightly: the hairline (cap or helmet), shoulders (straps), back (backpack), and chest (sports bra).

The solution is simple but often overlooked: wear looser fitting, breathable sportswear made of synthetic material that wicks away moisture instead of absorbing it. Wash sportswear after every workout. Use products that are free of comedogenic ingredients (ingredients that clog pores). And pay specific attention to the places where your equipment makes contact with your skin.

Zinc supplementation (15-30 mg per day) shows modest improvement in some studies for acne, possibly due to the anti-inflammatory effect. It is not a miracle cure, but it is a safe option to try if you suffer from mild to moderate acne and your zinc status may be suboptimal (which is the case for many athletes due to loss through sweat).

Fitness does not directly cause acne. But the habits that go along with an athletic lifestyle - sweat, nutrition, supplements - can. Adjust those habits and your skin usually recovers on its own.