The Science Is In: HYROX Is a Running Race in Disguise

For years, how to train for HYROX was mostly opinion. Everyone had a theory, and most of them centered on getting strong enough to muscle through the stations.

Then scientists actually studied it. The first peer-reviewed HYROX study wired up athletes through a full simulation and tracked their heart rate, blood lactate, and effort from the first run to the last wall ball. The results are clear, and they should change how a lot of people train.

Here’s the short version: HYROX is an endurance event wearing a strength event’s clothing. And if you’re training it like a lifting competition, you’re training the wrong thing.

What the HYROX Study Actually Did

Researchers took 11 recreational HYROX athletes and ran them through a complete Individual Open simulation, all eight runs and all eight stations, exactly to competition standard. Throughout, they measured heart rate, blood lactate, and perceived exertion at every run and every station, then looked at which fitness traits actually predicted a faster finish.

It’s a small study, so treat the exact numbers as a strong signal rather than gospel. But the picture it paints lines up with everything fast racers already feel, and now there’s data behind it.

Finding 1: It’s Mostly Running

The median finish was about 86 minutes. Of that, 51 minutes were spent running and just 33 on the stations.

Read that again. Nearly 60% of your race is the running. There are eight stations stealing all the attention, but the clock runs longest on the eight kilometers between them. This is the single most important thing the study confirms: if you want to get faster at HYROX, the runs are where the time lives.

Finding 2: You’re at the Red Line Almost the Whole Time

This isn’t a steady jog between stations. Athletes spent around 80% of the entire race at “very hard” intensity, sitting at 90 to 100% of their maximum heart rate. Blood lactate climbed to 8.5 and perceived effort hit 18 out of 20.

In plain terms, HYROX is a sustained near-maximal effort from gun to finish. That’s a specific kind of fitness, the ability to hold just under your red line without tipping over it, and it’s trainable. It’s also why people who only ever train slow miles or only ever train short and explosive both struggle. The race lives in the painful middle.

Finding 3: Wall Balls Are the Wall, and the Sleds Aren’t the Problem

The single most punishing moment of the race wasn’t the heavy sled. It was the wall balls. They produced the highest heart rate, the highest lactate, and the highest perceived effort of the entire event, which is brutal timing given they come dead last.

Here’s the counterintuitive part: the two heaviest stations, the sled push and sled pull, were completed the fastest, in roughly two and two and a half minutes. The stations that feel scariest on paper because of the load aren’t where your time goes. The bodyweight grind of wall balls at the end, when you’re already wrecked, is.

The training lesson writes itself. Train your wall balls when you’re already exhausted, not fresh, because that’s the only state you’ll meet them in on race day.

Finding 4: Your Engine Predicts Your Time. Your Strength Doesn’t.

This is the finding that should redirect a lot of training. When researchers looked at what actually correlated with a faster finish, three things stood out: a higher VO2 max, more endurance training volume, and lower body fat.

What didn’t predict a faster time? Grip strength. Raw resistance-training volume. The strength stuff.

That doesn’t mean strength is useless, you need enough to handle the loads safely and efficiently. But past that baseline, more strength isn’t what’s making people faster. A bigger engine is. The study’s own conclusion called HYROX an endurance-emphasis event with only moderate strength demands. The science agrees with the fast people: build the engine.

What This Means for Your Training

None of this is complicated to act on. It just means pointing your effort at the things that move the needle.

Run more, and run specifically. Since running is 60% of your race, it deserves more than a token session. And don’t just run fresh. Practice compromised running, the heavy-legged shuffle right after station work, because that’s what race running actually feels like.

Train the red line. Threshold work, intervals that park you at “very hard” and teach you to hold it, is the exact energy system the race demands. This is the gap between feeling fit and racing fast.

Stop chasing strength you don’t need. Build enough to move the sleds and carries efficiently, then put your extra hours into your engine. The data says that’s where the returns are.

Save some respect for the wall balls. They’re the physiological peak of the day and they come last. Train them under fatigue so they don’t end your race.

Pace the early runs. Going out too hot torches the back half, and the back-half runs are where finish times unravel. Patience early buys you the whole second half.

The Bottom Line

The science finally caught up to HYROX, and it settled the biggest training argument in the sport. This isn’t a strength event with some running tacked on. It’s a running event with stations attached, raced at the red line, won by whoever has the bigger engine and can still move when their legs are gone.

Train accordingly, and you’ll pass a lot of stronger people on the runs.

Based on Brandt et al., published in Frontiers in Physiology (2025), the first peer-reviewed physiological analysis of a simulated HYROX competition.