Elite male Flat jockeys display lower bone density and lower resting metabolic rate than their female counterparts: implications for athlete welfare.

To test the hypothesis that daily weight-making is more problematic to health in male compared with female jockeys, we compared the bone density and resting metabolic rate (RMR) in weight-matched male and female Flat jockeys. RMR (kcal·kg(-1) lean mass) was lower in males compared with females as well as lower bone-density Z scores at the hip and lumbar spine. Data suggest the lifestyle of male jockeys compromise health more severely than females, possibly because of making weight more frequently.