That’s right, exercise and sex, although not necessarily at the same time. In one recent study reported in the Wall Street Journal, researchers found that men and women who see themselves as equal partners in a relationship are more likely to participate in frequent recreational exercise compared with those in less egalitarian unions. People in relationships they regarded as totally gender-equal were two to three times as likely to engage in daily exercise as those in unions perceived as low in equality. In another study, cited in Science Daily, researchers found that when men assume more child-care duties, splitting them equally with their female partners, heterosexual couples have more satisfaction with their relationships and their sex lives. Wait, there’s more: when men do the majority of the child care, their female partners had the highest overall satisfaction with their sex lives, but men had the lowest overall satisfaction with their sex lives.