The format is simple to the point of cruelty: eight kilometres of running, cut into eight one-kilometre segments, with eight strength stations in between. Ski erg, sled push, sled pull, burpee broad jumps, rowing, farmer's carry, sandbag lunges, wall balls. Everything is standardised, so a result in Hamburg and a result in Melbourne are directly comparable.

In Russia the same niche is filled by hybrid races such as CRACE — the season final is on 5 September. And everyone thinking of entering has the same question: is this about strength or about running? There is now a measured answer.

What was measured in the lab

A group from the Bundeswehr University (Brandt et al., Frontiers in Physiology, 2025) put 11 trained amateurs through a full race simulation with continuous heart rate, lactate samples after every segment and Borg effort ratings. The participants' median VO₂max was 51 ml/kg/min.

Median time — 86.5 minutes. Of which:

running — 51.2 minutes, that is 59% of the total time;
stations — 32.8 minutes, 38%.

Then it gets interesting. The stations are shorter but harder. Mean heart rate on them was 173.7 versus 168.9 bpm for the running (p = 0.03), peak lactate 8.5 versus 7.7 mmol/l (p = 0.006), maximum RPE 18 versus 16 (p = 0.003).

79.5% of the whole race is spent at 90–100% of maximum heart rate. This is not “interval training with running breaks” — it is an hour and a half almost continuously in the red zone.

What predicts the result

Here the study gives the answer that is most inconvenient for marketing.

Finishing time correlates with:

VO₂max: ρ = −0.71 (p = 0.01) — the strongest relationship;
volume of aerobic training: ρ = −0.68;
body fat percentage: ρ = 0.67.

But grip strength, muscle mass and volume of strength training showed no significant relationship with anything. Nor did any individual characteristic correlate with time on the stations themselves.

A similar picture emerges from a large study of competition statistics (Rappelt et al., Frontiers in Physiology, 2026): 11,842 women's and 27,854 men's results in the PRO division across seven seasons. The running portion consistently takes up about half the time and at the same time reshuffles the placings the least — meaning running is precisely where the strong stay strong from race to race. Ski erg, rowing and burpees have barely improved over seven seasons; progress has come mainly from running and the sled stations.

The same work also shows how fast the format is professionalising: the elite men's median has fallen from 1:06:24 in the second season to 57:17 in the seventh, and the women's from 1:11:09 to 1:03:22. The spread of elite results has compressed from more than 10% to less than 5%.

Why the stations still cannot be ignored

“VO₂max predicts it” does not imply “strength work is unnecessary”. The logic here is different.

The sled push takes 2.1 minutes, the pull 2.6. These are the shortest episodes of the race, but they are exactly where the body goes into anaerobic glycolysis and carries the lactate out of it into the next kilometre of running. Wall balls — the last station — produced the maximum on all three measures at once in the study: heart rate, lactate, RPE.

So strength does not win the race, but a lack of it spoils the running. If the sled takes everything you have, you run the next kilometre on acidified legs, and the loss will come not on the station but after it. Tellingly, the slowest segment in the study was the fifth kilometre — 7.4 minutes, exactly the middle of the race.

Honest limitations

Eleven people. The sample is tiny, almost all with very good aerobic fitness, and eight of the eleven had above-average grip strength. In a group that homogeneous it is easy to miss a relationship with strength even where one exists: the spread is too small.

A simulation, not a race. Treadmill running indoors, alone, with no rivals and no spectators; the sleds were not the official ones. A competitive race is tactically different.

“Individual Open” only. The PRO, doubles and relay divisions were not tested, and the loads in them differ — in PRO the weights on the stations are noticeably higher.

The competition statistics are a database of self-reported data, and the authors specifically note: the length of the running segments could differ between events because of differing Rox Zone geometry, so the split cannot be analysed in detail on that basis.

What follows if you are planning to race

Prepare like an endurance athlete. If your week of hybrid-race training contains more strength work than running, you are preparing for the wrong sport. The aerobic base predicts the result; the strength base does not.
Run on acidified legs. The specificity of the format lies not in the stations or in the running separately, but in the transition. Drill the pairing “hard station → kilometre of running”, not each part in isolation.
Train the sleds separately. They are the only stations where technique and the ability to endure 2–3 minutes of supra-maximal effort translate directly into time, and where an unprepared athlete loses minutes rather than seconds.
Work on body composition. Body fat percentage correlated with the result more strongly than any strength metric. Which is logical: half the race you run, the other half you haul weight around, your own included.
Judge yourself by pace, not by iron. If you want to size up your chances, start with VO₂max and threshold pace, not with your bench press.

The bottom line

In the HYROX simulation, running took up 59% of the time (51.2 of 86.5 min), the stations 38%.
The stations are shorter but more intense: heart rate 173.7 versus 168.9, lactate 8.5 versus 7.7 mmol/l, RPE 18 versus 16.
79.5% of the race is spent at 90–100% of maximum heart rate.
The result is predicted by VO₂max (ρ = −0.71) and volume of aerobic training; grip strength, muscle mass and strength-training volume do not correlate.
Across 39,696 starts over seven seasons, running consistently takes about half the time and changes the placings the least.
The elite has got faster: the men's median 1:06:24 → 57:17, the women's 1:11:09 → 1:03:22.
The lab study's sample was 11 people and the simulation took place in a gym with no rivals; the conclusions are preliminary.

Sources: Brandt T., Ebel C., Lebahn C., Schmidt A. “Acute physiological responses and performance determinants in Hyrox© – a new running-focused high intensity functional fitness trend”. Frontiers in Physiology, 2025. DOI: 10.3389/fphys.2025.1519240 · Rappelt L. et al. “Longitudinal performance development in PRO and ELITE HYROX competitions across the first seven competitive seasons”. Frontiers in Physiology, 2026. DOI: 10.3389/fphys.2026.1847569