<P> Eating disorders (such as anorexia) are also very common among jockeys, as they face extreme pressure to maintain unusually low (and specific) weights for men, sometimes within a five - pound (2.3 kg) margin . The bestselling historical novel Seabiscuit: An American Legend chronicled the eating disorders of jockeys living in the first half of the twentieth century . As in the cases of champion jockey Kieren Fallon and Robert Winston, the pressure to stay light has been blamed in part for jockeys suffering agonies of thirst from dehydration while racing . Sports Dietitians Australia warns: "Dehydration and energy depletion may compromise concentration and coordination ." Indeed, recent research carried out in association with the Irish Turf Club measured the effects of rapid weight loss to make weight in professional and apprentice jockeys and found significant levels of dehydration; however, cognitive function was maintained, suggesting jockeys had become accustomed to performing in a dehydrated state and had potentially developed a preventative mechanism to enable them to perform under these conditions . </P> <P> In January 2016 it was announced that the International Concussion and Head Injury Research Foundation (ICHIRF) will run a new study . Named' Concussion in Sport' it will be the first study to take a detailed look at the effects of concussion on sports people, including around 200 retired jockeys . </P> <P> Based on American statistics, women comprise only 14 percent of working jockeys and ride only 10 percent of all race starts . Only two percent ride at the elite level of Triple Crown races . Gender discrimination is widely viewed as the cause, as far more women are capable of making weight as a jockey, and in most other equestrian disciplines, an overwhelming majority of participants are women . </P> <P> During the 1850s amateur "ladies only" events held in Victoria, Australia, women were not permitted to ride as professional jockeys or on professional tracks . </P>

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