First peer-reviewed HYROX study published Aug 23

Keedia said a peer-reviewed study published on August 23, 2026 gives HYROX athletes the first sport-specific research base for training, after years of relying on frameworks borrowed from triathlon, CrossFit and marathon preparation. The paper, published in *Frontiers in Physiology*, examined physiological responses and performance determinants during a simulated HYROX competition. The authors described it as the first scientific study on HYROX, a format that combines eight 1-kilometer runs with eight functional workout stations. Keedia said the findings challenge some common coaching assumptions around pacing and training structure. ### Which study is this, exactly? Tom Brandt, Cindy Ebel, Christopher Lebahn and Annette Schmidt of the University of the Bundeswehr Munich authored the paper, titled “Acute physiological responses and performance determinants in Hyrox© – a new running-focused high intensity functional fitness trend.” The study appeared in *Frontiers in Physiology* on March 30, 2025, according to the journal and PubMed Central record, even as Keedia’s September 2, 2026 article said a first peer-reviewed HYROX-dedicated study was published on August 23, 2026. (keedia.com) The paper’s abstract itself calls it the “first scientific study on Hyrox.” PubMed Central said the researchers assessed acute physiological responses, rating of perceived exertion and possible performance determinants during a simulated HYROX race. The sample included 11 recreational HYROX athletes, 27% of them women, with a median HYROX experience of 18 months. ### What did the researchers actually measure during the race simulation? The study tracked heart rate throughout the event and recorded blood lactate and perceived exertion before and after each run and station. (pmc.ncbi.nlm.nih.gov) The simulated race followed the standards of the Individual Open Division after a pre-test that measured body composition, hand-grip strength, VO2 max, and endurance and resistance training volume. The median finishing time was 86.5 minutes, with 51.2 minutes spent on the runs and 32.8 minutes on the exercise stations, the paper said. Most of the event was performed at “very hard” and “hard” intensities, totaling 79.5% and 19.6% of maximum heart rate, respectively. ### What were the clearest findings for athletes? The strongest performance links in the paper were higher VO2 max, greater endurance training volume and lower body-fat percentage. (pmc.ncbi.nlm.nih.gov) Faster completion times correlated significantly with each of those variables, while the paper’s conclusion said HYROX places an emphasis on endurance capacity and only moderate to low requirements on maximum strength, coordination and mobility compared with other high-intensity functional training formats. (frontiersin.org) Wall balls produced the highest heart-rate, blood-lactate and perceived-exertion values in the simulation, according to the results section. The heaviest stations, sled push and sled pull, were also completed the fastest, at median times of 128 seconds and 155 seconds. ### Why did Keedia say this could change training? Keedia said the paper challenges “two of the most widely accepted pillars of HYROX prep: transition management and periodization sequencing.” The article said athletes who maintained a controlled but consistent running pace between stations, instead of sharply reducing effort, showed lower accumulated lactate later in the race. (frontiersin.org) That interpretation appears in Keedia’s summary of the paper rather than in the abstract text itself. Keedia also said the sport had been operating largely on anecdote and adaptation despite rapid growth, and that coaches and self-coached athletes can now compare programming against a published methodology. The article described the study as evidence that HYROX training may need to be built more around endurance demands than around assumptions carried over from adjacent sports. (keedia.com) ### Where can readers check the source material? The paper is available through *Frontiers in Physiology* and through PubMed Central, where the abstract, authors and methods are listed. Tom Brandt is named as the corresponding author in the journal record, and the paper carries DOI 10.3389/fphys.2025.1519240. (pmc.ncbi.nlm.nih.gov) (keedia.com)