Abstract
Background: Horse racing is a unique and demanding weight-restricted sport which imposes considerable lifestyle challenges on jockeys. The difficulty achieving the low stipulated racing weights and the previously reported associated impact on compromised physiological function and health is a growing concern for the horse racing industry. The thesis aim was to investigate the body composition and bone density of jockeys, and to develop and evaluate industry specific nutrition education strategies.
Methods: The primary aim was achieved through the completion of three related studies. Study One conducted a large-scale evaluation of the current bone mineral density (BMD) status and associated physical and lifestyles factors of professional jockeys (flat n=39; national hunt (NH) n=46) in Ireland using a cross-sectional design with DXA scan, 24-hour food recall and lifestyle and injury history questionnaire. Study Two established body composition normative data for professional jockeys using DXA and skinfolds measurements and developed novel jockey-specific skinfold prediction equations for estimating body fat % (BF%). Study Three developed an online nutrition education (ONE) programme and compared this to the current nutrition education (CNE) practices in a 6-week dietary intervention trial with pre and post measures on body composition, dietary intake, nutrition knowledge and self-efficacy. Results: Study One confirms Irish jockeys have a high prevalence of low BMD (Z score of < - 1.0) at the lumber spine (LS) (44%), femoral neck (15%) and total hip (29%). Analysis indicated riding experience and timing of weight reduction in NH jockeys, and the practice of weight cutting in flat jockeys were seen to negatively influence BMD. The use of dietary supplements was positively associated with the LS in flat jockeys. In Study Two, results showed flat jockeys are heavier and taller than the data reported in earlier studies, with increasing BF% evident in both flat (15%) and NH (15.3%) jockeys. Jockey-specific skinfold equations developed using the available anthropometric variables showed a high predictive ability relative to DXA (R2 = .84 and .83, flat and NH, respectively). Study Three revealed ONE significantly improved nutrition knowledge and self-efficacy compared to CNE. Body composition was found to be comparable between the groups, despite a greater percentage of the ONE group showing improvements in fat mass (FM) loss and lean mass (LM) gain compared to the CNE group.
Conclusion: The present thesis reinforces and extends previous research, which suggests worrying trends of sub-optimal BMD and poor body composition in professional jockeys. The results identify for the first time modifiable risk factors that practitioners and the horse racing industry can use to improve the health, safety and well-being of jockeys. The thesis also offers a practical contribution to industry practitioners with body composition normative data, novel jockey-specific skinfold prediction equations and a bespoke nutrition knowledge questionnaire for jockeys. Moreover, ONE could be used to save time and resources by helping to replace or complement CNE. Further research beyond nutrition education is required to explore the range of factors that influence dietary behaviour in jockeys, including food availability, food costs and sport-specific factors like food provision at race tracks and weight cycling practices.
Methods: The primary aim was achieved through the completion of three related studies. Study One conducted a large-scale evaluation of the current bone mineral density (BMD) status and associated physical and lifestyles factors of professional jockeys (flat n=39; national hunt (NH) n=46) in Ireland using a cross-sectional design with DXA scan, 24-hour food recall and lifestyle and injury history questionnaire. Study Two established body composition normative data for professional jockeys using DXA and skinfolds measurements and developed novel jockey-specific skinfold prediction equations for estimating body fat % (BF%). Study Three developed an online nutrition education (ONE) programme and compared this to the current nutrition education (CNE) practices in a 6-week dietary intervention trial with pre and post measures on body composition, dietary intake, nutrition knowledge and self-efficacy. Results: Study One confirms Irish jockeys have a high prevalence of low BMD (Z score of < - 1.0) at the lumber spine (LS) (44%), femoral neck (15%) and total hip (29%). Analysis indicated riding experience and timing of weight reduction in NH jockeys, and the practice of weight cutting in flat jockeys were seen to negatively influence BMD. The use of dietary supplements was positively associated with the LS in flat jockeys. In Study Two, results showed flat jockeys are heavier and taller than the data reported in earlier studies, with increasing BF% evident in both flat (15%) and NH (15.3%) jockeys. Jockey-specific skinfold equations developed using the available anthropometric variables showed a high predictive ability relative to DXA (R2 = .84 and .83, flat and NH, respectively). Study Three revealed ONE significantly improved nutrition knowledge and self-efficacy compared to CNE. Body composition was found to be comparable between the groups, despite a greater percentage of the ONE group showing improvements in fat mass (FM) loss and lean mass (LM) gain compared to the CNE group.
Conclusion: The present thesis reinforces and extends previous research, which suggests worrying trends of sub-optimal BMD and poor body composition in professional jockeys. The results identify for the first time modifiable risk factors that practitioners and the horse racing industry can use to improve the health, safety and well-being of jockeys. The thesis also offers a practical contribution to industry practitioners with body composition normative data, novel jockey-specific skinfold prediction equations and a bespoke nutrition knowledge questionnaire for jockeys. Moreover, ONE could be used to save time and resources by helping to replace or complement CNE. Further research beyond nutrition education is required to explore the range of factors that influence dietary behaviour in jockeys, including food availability, food costs and sport-specific factors like food provision at race tracks and weight cycling practices.
Original language | English (Ireland) |
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Publication status | Published - Dec 2021 |