What compromised running is, and why HYROX is built on it
The rulebook sums the race up in one line: a 1 km run followed by one workout station, repeated eight times. The order is fixed, and each run is approximately 1,000 m, laid out in laps that depend on the venue. Only run 1 starts on fresh legs. The other seven begin as soon as you have left a station and crossed the Roxzone, the transition area between the stations and the run course.
Compromised running is the name for those seven runs: running well on legs a station has just used, with your heart rate still up from it. It matters because running is at least half the race: in the fastest 100 Pro results of each of seven seasons it made up about half of total race time, and in the first scientific study of the race, a simulated Open race, 11 recreational athletes took a median 86.5 minutes to finish and a median 51.2 minutes running.
Each station leaves its own mark. Piers Plowman, a former British triathlon performance coach and the HYROX Academy's education manager, describes legs like concrete after the lunges, a survival shuffle after the sled push and heavy, awkward strides after the burpee broad jumps. He also treats it as a skill you can coach, not a feeling you have to accept. The stations themselves are in the eight stations.
What happens in the first minutes off a station
The switch from one kind of effort to running has been studied most in triathlon, where the run starts straight off the bike. What follows is triathlon evidence. Cycling is not a sled push, so read it as the direction of the effect, not a forecast for your race.
- Running costs more for a while. A 2000 review of research on Olympic-distance triathlon, with training advice for junior and elite triathletes, found that running after the 40 km bike raised heart rate and breathing, and cost more energy than the same running done fresh, by an amount that depended on the athlete's level. Most stride measures did not change; the clearest change was a more forward-leaning trunk.
- An unsettled start is more likely, and longer, after a different effort. In 22 well-trained triathletes running 10 km outdoors, an unsettled phase at the start showed up in 18 of the 22 runs after a 40 km ride, 9 after a run of matched effort and 7 with nothing before it. Where it showed up, it lasted 679 m on average after the ride, 450 m after the run and 294 m with nothing before it. The authors placed the uncoordinated feeling in the first kilometre.
- Coordination came back within about three minutes. In nine highly trained triathletes running after 20 minutes of moderate cycling, the changes in how the thigh, shin and foot moved together had gone by the third minute of running.
Three things follow for HYROX. After the bike, all but four of these well-trained triathletes had an unsettled start, so the bad patch is normal, not a sign that something is wrong. A different kind of effort before the run made that patch more common and longer than the same work done running, and every station is a different kind of effort. And in these studies the worst of it came at the start, then passed.
Plowman names what a station's fatigue does to the run after it: posture goes, the stride shortens and cadence drops. That is what a brick trains.
Where the race slows you
Your runs also get slower as the race goes on, which is a different thing from the first-minute switch. The clearest published numbers come from 24 Pro men who raced HYROX Madrid 2025 within ten days of a lab test.
| Measure | Average speed | As a pace |
|---|---|---|
| Threshold speed in the lab | 16.41 km/h | 3:39 per km |
| Run 1 | 16.13 km/h | 3:43 per km |
| Run 8 | 13.58 km/h | 4:25 per km |
| Roxzone | 10.52 km/h | 5:42 per km |
Their running slowed progressively from run 1 to run 8, and the Roxzone was slower than any run. Their first run sat just under the threshold speed measured in the lab, and the authors concluded that sustaining a higher intensity relative to that threshold and their top aerobic speed appears central to a shorter total running time.
Read the shape, not the numbers. These are fast men at one venue, and runs are not identical from hall to hall: the seven-season study did not compare the eight runs one by one for that reason. Compare your own runs within one race, never against splits from a different venue. How to read your results for where the time goes is in getting faster at HYROX.
Brick workouts, from short to race-like
A brick is any session that puts running straight after another effort; the name comes from triathlon. Published guidance agrees on the direction more than the details. Coach Tiago Lousa's three-day plan for Red Bull keeps one running-focused session a week and turns it more HYROX-specific as race day approaches, mixing running with station work to practise pacing, transitions and working under fatigue. Plowman's advice is to plan pure running development alongside compromised sessions, placed by the athlete's stage of development. In triathlon, a review of elite short-course racing advises bike-to-run work at race intensity, while noting that how bricks train the switch is still poorly understood.
| When | What changes | Example session |
|---|---|---|
| Early in a build | One station, a short run, a controlled effort. The job is the first few hundred metres. | 4 rounds: 20 m of burpee broad jumps, then 400 m at a steady effort. Walk 2 minutes between rounds. |
| Middle of a build | Race weight at the stations that upset your stride most, and runs closer to 1 km. | 3 rounds: 25 m of sandbag lunges at race weight, then 1 km at the effort you plan to race. 3 to 4 minutes easy between rounds. |
| Last weeks before the race | Two or three stations in race order, at race weight and race effort. | 1 km, 50 m sled push, 1 km, 50 m sled pull, 1 km, with no rest beyond the walk to each station. |
Burpee broad jumps suit the first stage because they need no kit and leave the heavy, awkward stride Plowman describes; technique is in the burpee broad jumps guide. Whatever the stage, run the first minutes the same way:
- For the first few hundred metres, take short, quick steps and keep your chest tall, even if it feels slow. Where the bike left an unsettled start in the triathlon study, it lasted almost 700 m on average.
- When your breathing steadies and your stride lengthens on its own, build to the effort you plan to race.
- Hold that effort to the end of the run, before you rest or start the next station.
Plowman also uses running drills such as A-skips and bounding, and simple plyometrics such as hops, box jumps and bounds, to keep the stride springy when tired. They fit into a warm-up. More sessions, sorted by training block, are in the workouts library.
Keep your easy running while you add bricks
Bricks go on top of your running, not in place of it: in that simulated race, the faster finishers had a higher VO2max and did more endurance training. How much to run and why is in running for HYROX, threshold and interval sessions are in hard running workouts, and if you come to HYROX as a runner, running and HYROX in one week covers the other side.
The common mistake: turning every run into a brick
Once bricks start to work, it is tempting to put a station before every run. It costs more than it gives.
No brick is an easy session. A station before each run means none of your running is easy, and your threshold and interval runs get done on tired legs, slower than they should be.
Why runs on their own build the speed a brick then uses is in running for HYROX.
Bricks teach you to find your stride off a station. Runs on their own decide how fast that stride can be. Keep both in the week, and let the bricks grow more race-like as the race gets closer.
Bricks in Smash Coach
Open a session and tap START WORKOUT. Workout mode walks you through it one step at a time, counts your sets and your rest, and keeps the screen awake so you can leave the phone alone. A step with a time target counts down; everything else counts up and waits for you, and the timer keeps going with your phone locked in a pocket. More in Train with workout mode.
With Pro or during your trial, a plan built towards a HYROX race holds runs on their own as well as bricks. More in Races and events.