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<O.05) following RWL, although simple reaction-time was not. Given the occupational risks associated with race-riding, these data suggested that jockeys, who undergo even moderate reductions in body-weight through RWL, were potentially increasing these risks by compromising strength and performance. In Chapter 7, a scientifically devised dietary and exercise prescription was implemented over a 9-week period with a 22 yr-old male Jump jockey, to make minimum racing-weight that did not rely on previous habitual practices. Body-weight reduction of 8 kg over the 9-wk period was observed and achieved without food deprivation and dehydration. This was the first time that such a study had been conducted on a professional jockey. Throughout the intervention the jockey ate 6 regular meals daily and remained euhydrated with mean (± SO) 285 m.Osmo1.kg-1.bw ± 115 urine osmolality. GB jockeys demonstrate impaired markers of both physical and mental health which appear largely attributable to their habitual weight-making practices. These data suggest that Flat jockeys who are required to make significantly lighter racing-weight(s) than Jump jockeys, display the poorer markers. The daily EE of jockeys would suggest that food deprivation and sporadic eating (common methods) observed in food diaries are not necessary. Additionally, ~WL induced by sweating (another common method) impairs physical performance in Jockeys, which potentially increases the occupational risks associated with race-riding. Given the body-fat percentages observed in jockeys here, RWL may also not be necessary. As demonstrated, an alternative diet and exercise plan can be undertaken to safely make minimum racing-weight without relying on current weight-making methods that have been demonstrated in these studies to impair both health and performance in G8 jockeys.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:590097 |
| Date | January 2013 |
| Creators | Wilson, George |
| Publisher | Liverpool John Moores University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0023 seconds