Fasted Exercise and Increased Dietary Protein Reduces Body Fat and Improves Strength in Jockeys

Abstract

The present study assessed the effects of a diet and exercise intervention in jockeys on body composition, metabolism, bone and mental health. 10 jockeys followed an individually prescribed 6-wk diet (Carbohydrate=2.5-3.5 g/kg, Protein=2.5 g/kg, Fat=1.0 g/kg). Body mass (59.2±4.6 vs. 57.6±4.5 kg), fat mass (7.5±3.5 vs. 6.2±2.6) and body fat (13.1±5.9 vs. 11.5±4.9%) all decreased (P<0.05) from pre to post-intervention whilst lean mass (47.1±5.3 vs. 47.0±5.5 kg) was maintained (P=0.80). RMR (1703±329 vs. 1975±313 kcal.d(-1)), VO2max (3.8±0.8 vs. 4.1±0.7 L/min(- 1)) chest strength (65±11 vs. 71±13 kg), leg strength (160±28 vs. 175±29 kg) and jumping height (40±6 vs. 48±5 cm) significantly increased (P<0.05). Bone health (DXA) did not change (P>0.05) at hip (-1.04±1.29 vs. - 0.76±0.71) or lumbar sites (-1.32±0.76 vs. - 1.31±0.77). Psychometrics (GHQ-12 and EAT-26) remained unchanged (10.3±4.3 vs. 8.9±3.8 and 14.8±9.6 vs. 11.0±5.6, P>0.05, respectively). This approach represents a marked difference from jockeys' habitual weight-making that largely involves dehydration and food deprivation.

Case Study: Extreme Weight Making Causes Relative Energy Deficiency, Dehydration, and Acute Kidney Injury in a Male Mixed Martial Arts Athlete

“…Pasiakos et al 2013; Morton et al 2018;Longland et al, 2016;Wilson et al, 2013;Wilson et al, 2015). Nonetheless, we acknowledge the potential under-reporting associated with the dietary assessment measures utilised here (i.e.…”

The horseracing industry’s perception of nutritional and weight-making practices of professional jockeys

“…Referring back to the interviewees via member checking upon transcription and interpretation of themes similarly helped achieve a good standard of trustworthiness of the data. Alternative to seeking external modes of validation, the lead researcher consistently upheld a level of self-reflexivity and critical thinking throughout the duration of the study, contemplating his own views and ideologies to evidence sincerity in the process.The relevance, timing and significance of this topic in context of the horseracing industry and outcomes of previous quantitative enquiry(Dolan et al, 2011(Dolan et al, , 2012Wilson et al, 2012Wilson et al, , 2013Wilson et al, , 2014Wilson et al, , 2015) makes the present research a worthy topic.…”

“…The interview was centred on seeking the perceptions and thoughts of current weight-making practices in jockeys, how they identify jockeys in relation to other elite weight-making sportspeople, and their opinions of current race-day food provision at racetracks. Questions were devised with the outcomes of previous literature in mind (Dolan et al, 2011;Greene et al, 2013;Wilson et al, 2012;Wilson et al, 2013;Wilson et al, 2015) as well as the research group's own ideas in capturing the necessary responses to achieve the study aims.…”

“…Despite previous investigation and identification of these issues, it is as prevalent in the modern era globally as it was three decades ago (King and Mezey, 1987;Labadarious et al, 1993). In contrast to the aforementioned methods, recent research in professional jockeys has demonstrated that adherence to a high protein, low glycaemic-index carbohydrate diet (with total energy intake equivalent to resting metabolic rate) can facilitate fat loss whilst maintaining lean tissue and improving performance markers in elite jockeys (Wilson et al, 2012;Wilson et al, 2015). Despite the presence of these effective strategies for weight management in jockeys, a reliance on archaic practices still exists.…”

Energy expenditure in professional flat jockeys using doubly labelled water during the racing season: Implications for body weight management

“…In contrast to the aforementioned practices, we have recently shown that jockeys can make weight safely (Wilson et al, 2012;Wilson, Pritchard, et al, 2015) through the implementation of a structured dietary and exercise strategy. However, to provide individually tailored nutritional strategies for jockeys, it is essential to accurately calculate the daily total energy expenditure (TEE).…”