They are also recommended to perform muscle-strengthening (resistance or anaerobic) activity >2 days a week. 9 10Īdults are recommended to perform >150 min of moderate-intensity or >75 min of vigorous-intensity aerobic (endurance or cardio) activity a week. The incentive to perform intensive anaerobic training (IAT) is therefore strong, and some MSM spend long hours in gyms shaping their bodies, while some also adopt strict dietary regimens or are tempted to use anabolic steroids. 7 In addition, as gym training is an important component of the internal MSM culture, 8 the venue (gym) is also used for social interaction and meeting potential partners. In order to become physically attractive, some men train to increase muscle mass, shifting the focus of their training from aerobic to anaerobic training, and perform excessive muscle-strengthening exercises rather than improving their cardiac performance. Another theory is that the efforts of MSM to develop a muscular body are to counteract memories of having a less athletic, or even weak or feminine, appearance during their childhood and adolescence. 4 The shaping of a muscular body has become a symbol of health, 5 and MSM train in the gym in order to keep fit as a way of expressing that they are fit. MSM who develop a muscular body shape are usually considered more attractive and gain more self-confidence, 3 while those who fail to fulfil these aesthetic standards are less desirable and more likely tom be avoided by other men. 1 Body image is a multidimensional construct of the self, consisting of how one feels and behaves regarding one's own physical attributes 2 and correlates with well-being. Body image and masculinity are important aspects of identity in many men who have sex with men (MSM).