Exercise and hair

Key takeaways

• We found no human study showing that exercise causes or prevents pattern hair loss. The question is addressed mostly by indirect hormone studies and animal or cell work.
• The claim that lifting raises DHT and so makes you bald is not supported by hair data. A study of 28 cyclists (14 men, 14 women) found DHT rose with higher training volume, especially in women, but it measured hormones, not hair. Cook 2021 Follicle sensitivity, which is genetic, is the main driver of pattern loss. Heilmann-Heimbach 2020
• Irisin, a hormone released by exercising muscle, promoted hair growth in cells and mice. This 2024 study is preclinical and does not show workouts regrow human hair. Kim 2024
• Being under-fuelled is the bigger risk. Hard training with too little energy or iron can contribute to shedding (see diet and hair and iron and ferritin). In a survey of 300 exercising women, 12% were anaemic and 43% reported a history of iron deficiency, with heavy periods the main link. Dugan 2021
• Anabolic steroids and other androgenic drugs are a separate, real cause of hair loss in people who are predisposed.
• Sweat and hats affect hygiene and traction rather than follicle health. Wash off sweat if your scalp gets itchy or flaky, and avoid tight headgear for hours daily (see traction and hairstyles).

The science

Pattern hair loss depends on androgen signalling in genetically sensitive follicles and is highly heritable. Heilmann-Heimbach 2020 Exercise causes brief changes in testosterone and DHT, and the cycling study found DHT higher in high-volume training phases in both sexes, but no hair outcomes were measured. Cook 2021

What it means by hair profile

• Oily or flaky scalp: wash after heavy sweating; see washing frequency.
• Curly and coily hair: protective, low-tension styles for the gym; sweat can cause frizz and tangles (practical advice, not studied).
• Long hair: a loose braid instead of a tight ponytail during training.
• Fine or thinning hair: chlorinated pools and helmets raise breakage rather than loss; rinse and condition.

Myths and facts

• Lifting makes you bald: unproven; genetics decide susceptibility.
• Sweating clogs follicles and causes hair loss: no evidence found. Sweat sits on the scalp and can feed yeast, so wash.
• Cardio helps hair via blood flow: not shown.

Practical recommendations

• Exercise for general health; do not expect or fear hair effects.
• Eat enough energy, protein and iron to match training, and get ferritin checked if you shed.
• Avoid tight, long-duration headwear and heavy pulls.

Bottom line

Exercise is neither a proven hair treatment nor a proven cause of loss. Fuel it properly. Discuss with a doctor.