Daily, vigorous aerobic exercise (as opposed to short workout periods designed to raise androgen levels and build muscle, or more sporadic exercise) and a diet which is adequate yet more moderate in terms of fat and total calorie intake have been shown to reduce baseline insulin levels as well as baseline total and free testosterone.[3]
Lower insulin levels and reduced stress both result in raised levels of sex hormone-binding globulin (SHBG). SHBG binds to testosterone. Only free testosterone improves muscle growth and insulin sensitivity, but free testosterone can also be converted to the ineffective (regarding insulin sensitivity) DHT. The levels of free androgens and not of total androgens are relevant to the levels of DHT in the scalp and the progression of male pattern baldness. In short, aerobic exercise is capable of significantly lowering DHT.[4][5]
[3] Daly W, Seegers CA, Rubin DA, Dobridge JD, Hackney AC (January 2005). "Relationship between stress hormones and testosterone with prolonged endurance exercise". European Journal of Applied Physiology 93 (4): 375–80. doi:10.1007/s00421-004-1223-1. PMID 15618989.
[4] Barnard RJ, Aronson WJ, Tymchuk CN, Ngo TH (November 2002). "Prostate cancer: another aspect of the insulin-resistance syndrome?". Obesity Reviews 3 (4): 303–8. doi:10.1046/j.1467-789X.2002.00081.x. PMID 12458975.
[5]Barnard RJ, Aronson WJ (2005). "Preclinical models relevant to diet, exercise, and cancer risk". Recent Results in Cancer Research 166: 47–61. doi:10.1007/3-540-26980-0_4. PMID 15648182.