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,[12].
Lower insulin levels and reduced stress both result in raised levels of Sex Hormone Binding Globulin (SHBG). SHBG binds to testosterone, and prevents it from circulating free in the blood. Only free testosterone is converted to DHT. It is the level of free androgens and not total androgens which is 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. [13] [14] Reducing baseline Testosterone also limits the amount available to convert to DHT, but a balance has to be struck if one wishes to preserve Testosterone by concentrating on manipulation of the destructive form, DHT directly.[citation needed] However, exercise has not been shown to prevent male-pattern baldness. There is little doubt however, that overall fitness contributes to healthy hair growth, except where Testosterone increasing exercises are in excess of the threshold for DHT antagonism of the hair folicles.[citation needed]
Androgenic alopecia has been shown to correlate with metabolic syndrome. Medically increasing androgen levels does not worsen this condition, demonstrating that androgens do not cause metabolic syndrome. Instead, high insulin levels (and possibly chronic inflammation[15]) seem the likely link in the demonstrated correlation between baldness and metabolic syndrome. This reinforces the notion that behaviors which help to keep insulin levels low and reduce chronic inflammation might also help to preserve hair.[16][17]
