The aim of this study was to evaluate the impact of weight restrictions on physiological function and bone health in a group of horse racing jockeys. Twenty-seven elite male jockeys participated in this study (17 flat jockeys; 10 national hunt jockeys). Participants completed a range of measurements including anthropometry, hydration analysis, bone mineral density assessment, and musculoskeletal screening. Fifty-nine percent of flat and 40% of national hunt jockeys showed osteopenia in one or more of the total body, hip or spine scans. Mean urine-specific gravity (Usg) values revealed moderate dehydration on a non-race day (Usg = 1.022 +/- 0.005 and 1.021 +/- 0.007 for flat and national hunt jockeys respectively). Analysis of a number of flat jockeys (n = 11) revealed marked dehydration on an official race day (Usg = 1.028 +/- 0.005). Sixty-four percent of participants reported a current injury at the time of assessment. Our results reveal some worrying trends within this population. Further research is required to examine the effects of current weight control practices typically used by jockeys on both physiological and cognitive function as well as health and performance.