Health impacts of jockey weight-making measures warrant more research – review

"Most of the authors cited in this review have commented on the growing difference between minimum riding weights and increases in the mean body mass of a modern adult."
“Most of the authors cited in this review have commented on the growing difference between minimum riding weights and increases in the mean body mass of a modern adult.” Photo by Prete Moi Paris

Further research is necessary to better measure the health impact of weight-making behaviors among jockeys, according to the authors of a recently published review.

Dr Joseph Brodine and Dr Kelly Ryan, writing in the Open Access Journal of Sports Medicine, noted that many publications have described the behaviors employed by professional jockeys to achieve and maintain a minimum racing weight.

The pair, who cited 42 papers in their review, with a focus on those published since 2014, offered an update of recent research reporting on the impact of these practices.

“Although rapid weight-loss techniques such as calorie restriction and dehydration are commonly thought to be deleterious to jockeys, little evidence exists of enduring health consequences,” they said.

However, the evidence suggests that jockey training behaviors and dietary choices are not aligned with optimum preparation for the physiological demands of the sport.

More research into the health impacts of jockey weight-making behaviors might guide reforms of jockey behavior and regulatory practices within racing, they said.

The researchers noted that minimum weights for riding vary from country to country. Regardless of the jurisdiction, local and national racing weight limits are typically 10% or more below the average reference population and have not reflected the changes in mean weights of the reference population for the past century or more.

“Most of the authors cited in this review have commented on the growing difference between minimum riding weights and increases in the mean body mass of a modern adult,” they said. “In the US over the past 20 years alone, the average mass of an adult male has increased by 6.8kg despite the average height remaining constant.”

Despite advances in sports medicine and performance training, many jockey practices have been passed down through generations of riders uninformed by scientific insights, said the pair, who are with the Medstar Franklin Square Medical Center in Baltimore, Maryland.

Turning to weight loss strategies, they said most publications report that jockeys continue to rely on chronic weight cycling and unhealthy practices. These include severe restrictions on fluid and food intake, as well as passive strategies, such as sauna use, and active measures, such as intensive exercise in sweat suits.

One study of 85 Irish jockeys noted that 55.3% of participants reported difficulty with weight management and 67% reported that they rapidly lost weight at least once a month to race.

Practices known to result in dehydration have been consistently reported over the past two decades across jockey populations globally.

They said recently published literature reveals the effects of weight-making practices on key physiological systems and raises concerns about how those behaviors may affect performance and could potentially increase the risks of race riding. Several authors have tested an association between dehydration and key functional and clinical measures.

“In most sports, continuous hydration for performance is encouraged as body water and lean tissue are essential for optimal physiological function.”

Unlike other weight-restricted athletes, jockeys are weighed up to 10 times during a typical race day and are thus inclined to avoid rehydration or replenishing energy.

Jockeys, they said, typically reduce their body mass by 2 to 3% on race days, with one study noting a reduction by as much as 4.5kg (about 6.7% of body mass) to achieve the desired racing weight.

Brodine and Ryan, discussing their review findings, said traditional weight-making and physical preparation strategies for riding have emerged as a focal point for discussion as the number of publications on jockey health has increased over the past few decades.

“The studies presented in this review collectively indicate a need for industry-wide reform of common dietary practices and exercise regimens.”

Jockeys, they said, appear to underestimate their energy intake while needlessly restricting their nutritional intake in a way that does not benefit their performance and may result in certain adverse health consequences.

Typical dietary practices tend to be low in essential micronutrients and high in carbohydrates, an unnecessarily increased energy supply that is overmatched for the modest total daily energy demands of the sport.

Similarly, usual exercise regimens – trackwork – do not seem to benefit a rider’s metabolism or involve sports-specific conditioning to meet the greater demands of race-day.

“The apparent absence of routine aerobic endurance and high-intensity strength training may derive from a misconceived aim to avoid adding undesired muscle mass coupled with the perception that daily riding practices on non-racing days are adequate for preparation,” they said.

Researchers have consistently labelled jockeys’ weight-making practices as dangerous or harmful, the pair said. However, despite the intuitive reasoning behind this perception, there is little evidence of any particular chronic morbidity or acute injury associated with the weight-making practices in question.

The authors said the science describing the effects and weight-making practices among jockeys continues to mature and offer new insights.

“While future research could serve as a guide for athletes and trainers in a paradigm shift towards healthier nutritional behaviors and exercise regimens that more closely align with the actual physical demands of the sport, broader questions remain regarding the long-term effects of participating in a sport with unforgiving minimum riding weight limits.

“Both athletes and the horse racing industry must heed the science,” they said, “and move to embrace evidence-based practices as investigators continue to refine our understanding and better measure the consequences of this aspect of one of the world’s most popular sports.”

Ryan K, Brodine J. Weight-Making Practices Among Jockeys: An Update and Review of the Emergent Scientific Literature. Open Access J Sports Med. 2021;12:87-98

The review, published under a Creative Commons License, can be read here

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