title: The impact of making weight on physiological and cognitive processes in elite jockeys.
abstract: OBJECTIVE
  To examine the impact of making weight on aerobic work capacity and cognitive processes in a group of professional jockeys.
  
  
  METHODS
  Nine male jockeys and 9 age-, gender-, and BMI-matched controls were recruited to take part in two experimental trials, conducted 48 hr apart. The jockeys were asked to reduce their body mass by 4% in the 48 hr between trials, and controls maintained usual dietary and physical activity habits between trials. Aerobic work capacity was assessed by performance during an incremental cycle ergometer test. Motor response, decision making, executive function, and working memory were assessed using a computerized cognitive test battery.
  
  
  RESULTS
  The jockey group significantly reduced their body mass by 3.6 ± 0.9% (p < .01). Mean urine specific gravity (Usg) readings increased from 1.019 ± 0.004-1.028 ± 0.005 (p < .01) following this reduction in body mass. Peak work capacity was significantly reduced between trials in the jockey group (213 ± 27 vs. 186 ± 23 W, p < .01), although VO2peak (46.4 ± 3.7 vs. 47.2 ± 6.3 ml·kg·min-1) remained unchanged. No changes were identified for any cognitive variable in the jockey group between trials.
  
  
  CONCLUSIONS
  Simulation of race day preparation, by allocating a weight that is 4% below baseline body mass caused all jockeys to report for repeat testing in a dehydrated state, and a reduction in aerobic work capacity, both of which may impact on racing performance.
authors: School of Health Sciences, Robert Gordon University, Aberdeen, UK.
authors: Eimear
authors: E
authors: Dolan
authors: SarahJane
authors: S
authors: Cullen
authors: Adrian
authors: A
authors: McGoldrick
authors: Giles D
authors: GD
authors: Warrington
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology*; D003681:Dehydration / Q000503:physiopathology*; D004032:Diet; D016552:Ergometry; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D013177:Sports / Q000502:physiology*; D064133:Sports Nutritional Physiological Phenomena; D011795:Surveys and Questionnaires; D055815:Young Adult