Physiological Demands and Muscle Activity of Jockeys in Trial and Race Riding

SIMPLE SUMMARY: Jockeys are elite athletes and their performance during a race impacts not only their own injury risk and career longevity but also that of the horse they ride. The physiological parameters and muscle activity of jockeys during trials and races were quantified. This study found that trials act as a segue to race riding, with jockeys experiencing moderate to high-intensity effort during a trial, but using both their legs and (increasingly) arms to dampen horse oscillation. Jockeys riding in races exercise at near maximal physiological potential, using only their legs to dampen horse oscillation in a lower crouched posture than that adopted by jockeys in trials, with their centre of mass (COM) shifted anteriorly. Therefore, the competition (race) level performance demands of the jockey are not only higher than training level demands, but jockeys assume a different riding posture. Achieving race-specific fitness in readiness for competition is important for both horse and jockey safety, performance, and career longevity. Future physical training guidelines should aim to specifically target the physiological demands of race riding which are not addressed by training rides. ABSTRACT: Physiological parameters and muscle activity of jockeys may affect their fall and injury risk, performance, and career longevity, as well as the performance and welfare of the horses they ride. Therefore, this study aimed to quantify the physiological demands, body displacement, and electromyographic (EMG) activity of twelve jockeys riding 52 trials and 16 professional races. The jockeys were instrumented with heart rate (HR) monitors, accelerometers, and integrated EMG clothing (recording eight muscle groups: quadriceps, hamstrings, gluteal, erector spinae/lower back, abdominal external obliques, abdominal, trapezial and pectoral) which recorded continuously whilst riding. During race day, jockeys rode an average of 5 ± 4 trials and 4 ± 2 races over 2–2.5 h. The trials represented lower intensity cardiovascular demand (~81% HRmax) and Training Impulse (TRIMP) scores (4.4 ± 1.8) than races at maximal intensity effort (~94% HRmax, 7.2 ± 1.8 TRIMP, p < 0.05). Jockey head displacement was similar in trials (5.4 ± 2.1 cm) and races (5.6 ± 2.2 cm, p > 0.05), with more vertical (6.7 ± 2.7 cm) and less medio/lateral (2.3 ± 0.7 cm) and fore/aft (3.7 ± 1.6 cm) displacement for jockeys riding in trials than races (5.5 ± 2.3, 2.8 ± 1.0, 5.6 ± 2.5 cm, p < 0.05). Jockeys in races adopted a lower crouched posture, with their centre of mass (COM) shifted anteriorly, using greater hamstring activation and less upper arm muscle activation than in trials. The differences in riding posture and physiological demands on jockeys riding in a race rather than a trial, highlight the requirement for an off-horse race-specific training programme to improve jockey fitness and performance. Greater jockey stability and coordination will have mutual benefits for both horse welfare and performance.