Physical Activity and Risky Sexual Behavior in Men Who Have Sex with Men and Heterosexual Males in Tel Aviv, Israel

Background: Men who have sex with men (MSM), who engage in intensive anaerobic training (IAT) and become physically attractive, increase the number of sex-partners and their risk for sexually transmitted infection and HIV. This study compared training practices between MSM and heterosexuals, and associated IAT with sexual behavior.

Methods: This cross-sectional study included a sample of men from five gyms, who completed anonymous questionnaires. Trainees who exercised more than the median anaerobic training hours were regarded as IAT, and those who performed one unprotected anal/vaginal-intercourse in the previous six months were defined as sexually risky.

Results: In 2011, 184 (48%) MSM and 197 (52%) heterosexuals completed the questionnaire. MSM showed a stronger desire to become muscular than heterosexuals, reported more weekly hours of IAT and used protein powers or anabolic steroids more commonly than heterosexuals. MSM reported that the main reasons for training were refining body-shape and improving self-confidence, while heterosexuals indicated that weight-loss and health improvement were the main reasons for training. MSM were more sexually risky than heterosexuals.

Of all the sexually risky, 61.9% (n=70) performed IAT, while 38.1% (n=43) performed moderate anaerobic training. This association was stronger among MSM than in heterosexuals. In a multivariate analysis, MSM, younger age, dissatisfaction with body shape, desire to be more attractive, and higher sexual obsession score predicted IAT. The interaction between MSM and IAT among risky participants was multiplicative.

Discussion: MSM practiced more IAT than heterosexuals, and their interaction between IAT and sexual risk was multifactorial. Gym trainers can educate MSM in moderating IAT.