Prevalence, burden and risk markers of health problems in HYROX athletes: a 12-week prospective cohort study

HYROX is a rapidly growing fitness competition combining eight 1-km running intervals with eight functional fitness stations. This study investigated the epidemiology and markers of health problems in HYROX athletes.

Eighty-nine HYROX athletes (56 female) completed the 'Oslo Sports Trauma Research Center Questionnaire on Health Problems' (OSTRC-H2) weekly for 12 weeks, alongside exposure reporting and a baseline questionnaire. In an exploratory analysis, potential risk markers (age, sex, previous injury and HYROX experience) for cumulative injury severity were examined using negative binomial regression with an exposure offset.

The mean weekly response rate was 62%. The pooled weekly prevalence of any health problem was 30% (95% CI 24% to 37%), with a substantial-problem prevalence of 18% (95% CI 13%-24%). Injury incidence was 14.4 (95% CI 11.1-18.4) per 1,000 h, with a time-loss incidence of 6.4 (95% CI 4.3-9.2); injuries attributed to HYROX training accounted for two thirds of episodes (9.6 per 1,000 h). Overuse injuries accounted for 73% of injuries. The knee was the most frequently injured region (22% of episodes) and, with the lower leg, carried the greatest burden; the elbow ranked third for burden on the basis of four episodes, two of them persistent, while shoulder injuries were near-absent. Previous injury carried the largest rate ratio for cumulative severity, at 2.60 (95% CI 1.00-6.75), an interval also compatible with no association.

Health problems were common in HYROX athletes and dominated by overuse injuries. The burden was led by the lower limb, consistent with the sport's running load, with a possible elbow contribution from two persistent injuries and a near-absence of shoulder problems, a combination that may distinguish the profile from other extreme conditioning programme training but which rests on few cases. Only half of problems involved time-loss, so missed-training-day surveillance understates the burden. Previous injury is a candidate risk marker requiring confirmation in larger cohorts.