Today in Science: Racehorse Performance Has No Relation to the Sex of the Jockey

It’s a man’s world… except when it isn’t. Experts from the University of Nottingham have found that the sex of a jockey doesn’t influence any aspect of racehorse physiology and performance. 

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Experts from the University of Nottingham have found that the sex of a jockey doesn’t influence any aspect of racehorse physiology and performance.

The findings of the study, published at Research Square, offer a new perspective on the possible balance of elite male and female jockeys on the start line of races.

Studies assessing the effect of the sex of a rider on racehorse performance and physiology during training have not been reported, mostly due to the lack of available data for female participants within the sport.

In the present day, more than 90% of jockeys, in most racing nations, are men. This is likely an unconscious bias toward male jockeys being, on average, physically ‘stronger’, able to push horses harder, and thus performing better in races than female jockeys.

This decade has seen a marked increase in participation of female jockeys at an elite level in the racing industry. In 2021, the Irish jockey Rachael Blackmore made history by winning several high-profile races. Success stories, like this, are shaping global betting behaviours on the racetrack and challenging the public’s confidence in the ability of male or female jockeys to win big races.

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In the UK and Ireland, previous research had suggested an underestimation of the ability of female jockeys to win races, as recorded in betting behaviour. In racing, a competitive advantage may lie in the ability of a jockey to control the horse, and/or less weight carried by the horse (i.e. weight of jockey plus saddle). Hence, jockeys are weighed in before, and weighed out after, races. Certain races are ‘handicapped’ by weight carried and according to predicted ability. All being equal, would a racehorse during race-pace work-outs perform any differently when ridden by either a female or male jockey? Would that racehorse be more or less likely to win a race?

Researchers from the School of Veterinary Medicine and Science at the University of Nottingham, worked with Guillaume Dubois PhD Scientific Director at Arioneo Ltd– a company that developed a bespoke exercise tracking device for horses; and an Equine Sports Medicine specialist (Dr Emmanuelle van Erck-Westergren PhD; Equine Sports Medicine Practice, Belgium) to answer some of these questions.

They monitored 530 thoroughbred racehorses, ridden by 103 different work riders (66 male, 37 female) over a total of 3,568 work-outs at a single racing yard (Ciaron Maher racing) in Victoria, Australia. Variables such as speed, stride length and frequency, horses heart rate and rate of recovery were recorded with a validated fitness tracker (the ‘Equimetre’©). This tracker was specifically designed to monitor horses during their daily exercise routine with advanced data analysis services (

The investigators found no effect of sex of the jockey on any objectively measured outcome variable, measured from slow-canter to hard, race-pace gallops. But would this lack of effect of sex of jockey in training, also translate to actual race results, where many other variables come into play?

Analysing results from 52,464 races, female jockeys had a similar win percentage (of total race starts) as male jockeys in the UK (female, 10.7% vs. male, 11.3%). In Australia, male jockeys had a slightly higher win percentage (11.0 vs. 9.9%), but this was negated when considering a top three race finish.

Taken together, the researchers found minimal effect of the sex of the jockey on both training and race outcomes. Some curious effects were observed. For example, recovery of racehorse heart rate after exercise appeared influenced by sex of the rider, but only when the usual training intensity on each track surface (grass or sand) was reversed.

Male work-riders, more so than female, perhaps anticipated the ‘expected’ training-intensity (e.g. gallop on grass) and their proposed anticipation was transmitted faithfully to the horse, who responded with higher or lower heart rate. Further work is needed, however, to confirm this effect. When considered across all training sessions, then no difference in expected recovery rates of racehorses were noted between male and female jockeys.

Ms Charlotte Schrurs (PGDip VetPhys, MSc), doctoral student and lead author with Professor David S Gardner, said: “Our study is the first to objectively assess whether the sex of a jockey has an influence on any aspect of racehorse physiology and performance. The data convincingly suggest the answer is no and offers a new perspective on the possible balance of elite male and female jockeys on the start line of races. Efforts to favour a more ‘inclusive environment’ would greatly contribute towards equal opportunities and the promotion of fair competition within this highly popular and fascinating sport.”

You can read the full study here.

About the University of Nottingham:
The University of Nottingham is a research-intensive university with a proud heritage. Studying at the University of Nottingham is a life-changing experience, and we pride ourselves on unlocking the potential of our students. We have a pioneering spirit, expressed in the vision of our founder Sir Jesse Boot, which has seen us lead the way in establishing campuses in China and Malaysia – part of a globally connected network of education, research and industrial engagement. Ranked 103rd out of more than 1,000 institutions globally and 18th in the UK by the QS World University Rankings 2022, the University’s state-of-the-art facilities and inclusive and disability sport provision is reflected in its crowning as The Times and Sunday Times Good University Guide Sports University of the Year twice in three years, most recently in 2021. We are ranked eighth for research power in the UK according to REF 2014. We have six beacons of research excellence helping to transform lives and change the world; we are also a major employer and industry partner – locally and globally. Alongside Nottingham Trent University, we lead the Universities for Nottingham initiative, a pioneering collaboration which brings together the combined strength and civic missions of Nottingham’s two world-class universities and is working with local communities and partners to aid recovery and renewal following the COVID-19 pandemic