The effects of weight-making on the physical and mental health of professional jockeys

Professional jockeys are unique amongst weight-making athletes in that they are required to make-weight daily, and compete at different weights. Additionally, jockeys are unique in that they are required to be weighed both pre- and post-competition. Amongst the most common methods to reduce body-weight are acute and chronic dehydration and food deprivation. Such practices are suggested to be detrimental to the general health of jockeys. In Chapter 4, an assessment of the physical and mental health of 37 GB professional jockeys (19 Flat jockeys and 18 Jump jockeys), was undertaken and comparisons with clinical norms and between groups were made. This was the first time that such a study had been undertaken. Impaired markers of bone health, inadequate dietary practices including low micronutrient status, and abnormal mood profiles were identified in both groups. Additionally, Flat jockeys displayed significantly poorer bone density (p<0.01) and mood-state (p<0.05) than Jump jockeys. Both jockey groups also displayed higher percentage body fat than in other athletic groups, which demonstrated that there was scope to reduce body-weight which could in-turn negate the need to starve and/or sweat. In Chapter 5, the energy expenditure (EE) of simulated race-riding was measured in 9 Jump jockeys, and the daily EE was assessed in 8 Jump jockeys, on a non-race-riding day. Additionally, the daily energy intake (El) of 8 Jump jockeys was also analysed. Previously, these data were unknown. Simulated race-riding EE was mean (± SO) 0.20 MJ ± 0.03. Daily EE was 11.26 MJ ± 1.49 and daily EI was 7.24 MJ ± 0.92 that largely consisted of two main meals. These data demonstrated that jockeys displayed sporadic eating patterns with large gaps observed between food consumption, and given the daily EE that such eating habits may not be necessary, in order to make minimum weight. In Chapter 6, the effects of a 2% reduction in body-weight through rapid weight-loss (RWL) was measured in 8 jockeys (6 Jump jockeys and 2 Flat jockeys) on physical and cognitive performance. This body-weight reduction was induced by exercising in a sweat-suit (a common weight-making method used by jockeys). To date, these data were previously unreported. Maximal riding performance and chest and leg strength were significantly reduced (p