What does a HYROX world champion's physiology look like?
One man: 80.7 kg, VO2max 61.3 mL/kg/min, 16 h/week (10 running), oxygen cost like elite runners by the authors' reading. It describes him; it is not a target for anyone.
Main caveat: One athlete, one day. No control or repeat; the authors ask whether these are his idiosyncrasies or general.
Schwalm and colleagues tested a men's HYROX Elite 15 world champion on one day. He did a step and ramp treadmill test, then after 15 min a self-paced partial simulation of 5 × 1 km runs separated by row, farmers carry, sandbag lunges and burpee broad jumps (replacing wall balls because of the ceiling), then after 15 min the step and ramp test again.
Gas exchange was not measured during the simulation. VO2max fell from 61.3 to 57.0 mL/kg/min; energetic cost at 16 km/h moved from 3.92 to 3.89 J/kg/m; lactate at 15 km/h and above read lower and the lactate-based thresholds higher, which the authors warn may reflect low carbohydrate availability.
Runs in the simulation were 3:17-3:30; a race 10 days later gave 3:28-3:42 for the runs after the same stations. Step rate was lowest after the lunges. Our reading: a careful description of one man, with a fine oxygen cost for his size, and the first run mechanics in this setting.
It cannot show that stations harm running, since his slowest lab run also had his lowest RPE, which the authors put down to easing toward a steady state, and it cannot show durability in anyone else.
Protocol
Participant: n = 1; male, 25 y, 180.8 cm, 80.7 kg, body fat 5.8%. HYROX Pro Single best 56:19, Double 50:24; a 2025 Elite 15 world title. 10-km 33:00 and marathon 2:36 (running Tier 2 by the authors). Youth football to 16; HYROX training since 2021, exclusively since 2024. 16 h/week: 10 h running, 4 h specific strength, 2 h competition-specific.
Day: warm-up; countermovement and standing broad jumps; Pre-Step-Ramp; 15 min standing; partial simulation; 15 min standing; Post-Step-Ramp. About 2 h in all, one session, September 2025.
Step and ramp: 3-min stages, +1 km/h from 12 km/h at 0.5% incline; then +0.5 km/h every 30 s to exhaustion once the second threshold was suspected. Lactate after each step.
Simulation: 5 × 1 km treadmill runs, speed self-chosen with the display hidden, started at 17 km/h. Between runs in this order: row 1000 m, farmers carry 200 m (2 × 32 kg), sandbag lunges 100 m (30 kg), burpee broad jumps 80 m, in a 10-m corridor. Lactate and RPE after each section. No gas exchange during the simulation.
Race comparison: net split times from a Pro Single race 10 days later.
Measures: gas exchange (metabolic cart), capillary lactate, RPE 6-20, chest-strap heart rate, markerless motion capture and pressure plate. Thresholds: LT1 = 0.4 mmol/L above the lowest value; LT2 = LT1 + 1.5 mmol/L. VO2max = highest 30-s moving average. Post-test values used body mass measured directly after the second test.
Fuel: carbohydrate-rich diet the day before and the day of testing; 20 g carbohydrate and 188 mg sodium 40 min before and after the first test; water ad libitum. Advanced footwear (Puma Nitro Elite Hyrox Edition) for treadmill work.
Funding and interests: no funding. K. Hollander is Chief Medical Officer (honorary position) of the German Athletics Association (DLV, sponsored by Nike) and Team Physician of the German Ski Association (DSV, sponsored by Adidas), and the paper states these did not influence the work; L.Schwalm co-founded and co-owns an endurance coaching company, Nordlicht-Ausdauer-Coaching; others none. Open access funded through Projekt DEAL. A gym provided the HYROX equipment. Ethics approved (MSH-2022/172); not preregistered.
Key Results
| Station | Simulation | Race 10 days later |
|---|---|---|
| First run | 3:22 | 3:19 |
| Row 1000 m | 3:36 | 3:54 (includes an unspecified distance from the timing gate to the rower) |
| Run after row | 3:23 | 3:28 |
| Farmers carry | 1:41 | 1:34 |
| Run after carry | 3:22 | 3:29 |
| Sandbag lunges | 3:38 | 3:17 |
| Run after lunges | 3:30 | 3:42 |
| Burpee broad jumps | 2:56 | 2:48 |
| Run after burpees | 3:17 | 3:42 |
| Step and ramp | Before | After |
|---|---|---|
| VO2max | 61.3 mL/kg/min | 57.0 mL/kg/min |
| Energetic cost, 16 km/h | 3.92 J/kg/m | 3.89 J/kg/m (0.7% lower) |
| LT1 speed | 15.4 km/h | 16.4 km/h |
| LT2 speed | 17.5 km/h | 18.0 km/h |
| Ramp end | 22.5 km/h | 22.5 km/h |
| Body mass | 80.7 kg | 77.1 kg |
In the simulation: about 17.8 km/h on the first three runs, 17.1 km/h on the fourth, 18.3 km/h on the last (authors' averages). Lactate about 4 to 5 mmol/L on the runs; highest overall 8.5 mmol/L with RPE 19 on the final run; 7.7 mmol/L with RPE 18 on the burpees. RPE about 15 until the lunges.
Oxygen cost: about 185 mL/kg/km, which the authors place at the level of elite runners while noting his larger mass.
Mechanics: lowest step rate 162.8 steps/min at the end of the run after lunges, which was also the slowest run; vertical pelvis motion 8.7 cm after the carry and lunges, 8.0 cm at the start of the last run. After against before: step rate −2.1 steps/min, contact −5.1 ms, flight +10.1 ms on average.
Jumps: countermovement 41.5 ± 0.9 cm; standing broad jump 229.7 ± 3.9 cm.
Does not add up: the paper says VO2max fell 7.5%; 61.3 to 57.0 is 7.0%. And with mass down 3.6 kg (4.5%), absolute VO2max fell about 11%, more than the relative figure shows (our arithmetic; a post-test economy per kg is also computed on the lighter mass).
Mechanisms
Measured: one athlete, one day, pre and post.
Authors' interpretation: excellent VO2max and an even better running economy; excellent physiological durability in their word, acute and in this one athlete, since economy and lactate at 16 km/h and above were not worse. They attribute this reasonably, not causally, to years of combined training.They suggest leg-dominant stations produced local fatigue that lowered step rate, while noting speed also lowers step rate, and that the last run was fastest because he knew it was last.
Authors' caveat: lower lactate may come from low carbohydrate availability, so the lactate and threshold changes should be read carefully.
Inference: three facts stop the run-time columns from being a penalty. The burpees came last here and fourth in a race; the lab runs were self-paced on a treadmill after a maximal test, while the race carried eight runs and eight stations; and exercises were done in a 10-m corridor with more turns.
Practical Application
What does a HYROX world champion's physiology look like? One man: 80.7 kg, VO2max 61.3 mL/kg/min, 16 h/week (10 running), oxygen cost like elite runners by the authors' reading. It describes him; it is not a target for anyone.
Testing idea (the authors' proposal, untested): a step test before and after a partial simulation, or on separate days, may show how an athlete runs under fatigue. Its reliability and worth are unknown; the authors note that a maximal test before the simulation disturbs both. Not from this paper; the base's own practice on testing is in SYNTH-53.
Volume is one data point: 16 h/week, with 10 h of running, is what this champion reports; not a dose finding.
What it adds on running after stations: a single observation. In the lab his self-paced run speed did not fall steadily; in the race 10 days later his runs slowed from 3:19 to 3:42. Step rate may fall after leg-heavy stations. REF-1498 gives the field-scale view, as a preprint.
Limitations
One athlete, one day. No control or repeat; the authors ask whether these are his idiosyncrasies or general.
A partial simulation. Half the stations, a different order, a replaced station, treadmill running, a 10-m corridor, and a maximal test just before it. The authors say this may have shaped both the simulation and the second test.
Carbohydrate. Below recommendations during a 2-h protocol; may lower lactate and shift lactate-based thresholds.
Self-paced, speed hidden. Speed changes mix pacing with fatigue. No gas exchange during the simulation.
Not preregistered. Supplementary biomechanical tables were not read.
Interests. Federation roles of one author (one stated as honorary) and a coaching company of the first, as stated; no funding. He wore a named commercial racing shoe (Puma); no sponsorship of the study is stated and no shoe effect claimed.
How this entry was checked and changed
Why this level
single case study by the rubric, read in full (open access, CC BY 4.0); not preregistered, one session
Full text (checked 2026-10-30)
Elite 15 world title in 2025; tier 5 for HYROX, tier 2 for running; 16 h/week, 10 h running, 4 h specific strength, 2 h competition-specific (full text)
VO2max 61.3 before, 57.0 after, stated as 7.5% lower; energetic cost 3.92 and 3.89 J/kg and m at 16 km/h (full text)
LT1 15.4 to 16.4 km/h; LT2 17.5 to 18.0 km/h; ramp end 22.5 km/h both times (full text)
Run after row 3:23 vs 3:28, after carry 3:22 vs 3:29, after lunges 3:30 vs 3:42, after burpees 3:17 vs 3:42 (full text)
Running speeds 17.8 km/h on the first three, 17.1 km/h on the fourth, 18.3 km/h on the last; last-run lactate 8.5 mmol/L, RPE 19 (full text)
Lowest step rate 162.8 steps/min after the sandbag lunges; body mass 80.7 kg to 77.1 kg (full text)
Funding none; K. Hollander's federation roles and L. Schwalm's coaching company declared (full text)