Despite consistent reports of poor bone health in male jockeys, it is not yet known if this is a consequence of low energy availability or lack of an osteogenic stimulus. Given the rationale that low energy availability is a contributing factor in low bone health, we tested the hypothesis that both hip and lumbar bone mineral density (BMD) should progressively worsen in accordance with the years of riding. In a cross-sectional design, male apprentice (n = 17) and senior (n = 14) jockeys (matched for body mass and fat-free mass) were assessed for hip and lumbar spine BMD, as well as both measured and predicted resting metabolic rate (RMR). Despite differences (p < .05) in years of race riding (3.4 ± 2 vs. 16.3 ± 6.8), no differences were apparent (p > .05) in hip (−0.9 ± 1.1 vs. −0.8 ± 0.7) and lumbar Z-scores (−1.3 ± 1.4 vs. −1.5 ± 1) or measured RMR (1,459 ± 160 vs. 1,500 ± 165 kcal/day) between apprentices and senior jockeys, respectively. Additionally, years of race riding did not demonstrate any significant correlations (p > .05) with either hip or lumbar spine BMD. Measured RMR was also not different (p > .05) from predicted RMR in either apprentice (1,520 ± 44 kcal/day) or senior jockeys (1,505 ± 70 kcal/day). When considered with previously published data examining underreporting of energy intake and direct assessments of energy expenditure, we suggest that low BMD in jockeys is not due to low energy availability per se but rather the lack of an osteogenic stimulus associated with riding.
George Wilson, Dan Martin, James P. Morton and Graeme L. Close
George Wilson, Neil Chester, Martin Eubank, Ben Crighton, Barry Drust, James P. Morton and Graeme L. Close
Professional jockeys are unique among weight-making athletes, as they are often required to make weight daily and, in many cases, all year-round. Common methods employed by jockeys include dehydration, severe calorie restriction, and sporadic eating, all of which have adverse health effects. In contrast, this article outlines a structured diet and exercise plan, employed by a 22-yr-old professional National Hunt jockey in an attempt to reduce weight from 70.3 to 62.6 kg, that does not rely on any of the aforementioned techniques. Before the intervention, the client’s typical daily energy intake was 8.2 MJ (42% carbohydrate [CHO], 36% fat, 22% protein) consumed in 2 meals only. During the 9-wk intervention, daily energy intake was approximately equivalent to resting metabolic rate, which the athlete consumed as 6 meals per day (7.6 MJ, 46% CHO, 19% fat, 36% protein). This change in frequency and composition of energy intake combined with structured exercise resulted in a total body-mass loss of 8 kg, corresponding to reductions in body fat from 14.5% to 9%. No form of intentional dehydration occurred throughout this period, and mean urine osmolality was 285 mOsm/kg (SD 115 mOsm/kg). In addition, positive changes in mood scores (BRUMS scale) also occurred. The client was now able to ride light for the first time in his career without dehydrating, thereby challenging the cultural practices inherent in the sport.