Hyrox has taken the fitness world by storm: a global phenomenon that’s attracting everyone from elite athletes chasing sub-60-minute PBs to first-timers who simply want to find out what they’re made of.

The race format – eight 1km runs, each followed by a functional exercise station ranging from sled pushes to burpee broad jumps to wall balls – demands running legs, a powerful upper body and the kind of cardiovascular engine that can keep firing long after every muscle is screaming at you to stop.

At first glance, indoor cycling has no place here. There’s no bike on the race floor, no wattage target to hit, no RPM to chase, no final sprint to the beat. Yet speak to the coaches, instructors and operators who are most serious about training for Hyrox events – ask them what they put at the heart of their training programmes – and the answer keeps coming back to the same place. The indoor cycling studio.

Building the aerobic engine

Hyrox may look like a strength event with some running thrown in, but in reality, the aerobic engine matters far more than many athletes realise.

That’s certainly the view of Meaghan St Marc, co-founder and co-CEO of Revd Fitness in the US, who recently completed a Hyrox event using Revd as her primary training facility. Revd isn’t a Hyrox Performance Center, nor does it run Hyrox-specific classes, but it has a strong community of Hyrox enthusiasts among its members and instructors, many of whom use its workouts to support their race prep.

According to St Marc, first-time competitors often focus their training around the obvious bits: the functional stations that stand out on the race floor. But when it comes to the clock, she says, it’s often the running that does the damage: “People get really focused on the sled push and pull, the farmer’s carry, the wall balls – but then they get to the run and that’s where they lose all their time.”

“Most people aren’t able to run enough to get the aerobic engine they need to sustain a solid Hyrox output”

“If you struggle through the runs, you’re exhausted by the time you get to the exercises,” confirms Rachael Penrose, an indoor cycling instructor, personal trainer and strength & conditioning coach based in London, UK.

That doesn’t mean the stations don’t matter. They do. But if athletes want to move well through the whole event – and especially if they want to improve from one Hyrox to the next – St Marc and Penrose suggest they may need to spend less time obsessing over individual stations, more time building the cardiovascular capacity that connects them all together.

Indeed, when cardio capacity is well-developed, the running sections can become a form of active recovery on race day, says Penrose: “In my first Hyrox last year, I was able to complete the runs without too much stress on my body, keeping my heart rate under control. It meant I arrived at each station with the energy to really push into it.

“I wasn’t running much in preparation for the event – I just hadn’t found the time – so I wholly put that down to coaching indoor cycling.”

Transferable benefits

Let’s be clear: our experts aren’t suggesting that would-be Hyrox participants shouldn’t do race-specific training, including getting their running up-to-scratch. They are, however, suggesting that running isn’t the only way to build the cardiovascular engine you need for these events.

“Most people aren’t able to run enough to get the aerobic engine they need to sustain a solid Hyrox output,” confirms Mandi Lora, owner of Rout3 Health & Performance in Woodstock, Georgia – a fully-affiliated Hyrox Training Club that programmes indoor cycling directly into its Hyrox sessions.

“When you’re trying to increase your aerobic or anaerobic abilities, it doesn’t matter what cardiovascular modality you’re using”

It is the repeated musculoskeletal pounding of running that makes this a challenge, particularly in a training programme that’s already likely to include a lot of jumping, lunging and loaded movement. Cue indoor cycling – a low-impact way to build cardio training volume when the limiter isn’t the heart and lungs, but the body’s ability to tolerate more impact.

Lora explains: “When you’re trying to increase your aerobic or anaerobic abilities, it doesn’t matter what cardiovascular modality you’re using. It’s simply about training your body to do more work at a lower heart rate.”

That idea is well supported by the wider literature, with research consistently showing that aerobic adaptations can transfer between modalities. In simple terms, the cardiovascular system doesn’t care whether the stress is created by a treadmill, an indoor bike or a road run: if you spend enough time working at the right intensity, you can improve aerobic capacity and VO2 max. Recovery is also quicker with low-impact cycling, meaning you can train more.

It’s why Everlast Gyms, Hyrox’s exclusive UK Performance Center partner, prescribes indoor cycling for what it calls “off-feet training”. And why Lora ultimately returned to the bike when training for a Hyrox event herself.

She explains: “Historically I’m not a runner, so at first I almost exclusively got rid of biking to ramp up my running. I was very diligent with slow, steady progression – a 10 per cent increase every week – but the wear and tear on my body was significant.

“If you continue with that sort of wear and tear, at a certain point you won’t be able to work the energy system as effectively.”

And so she returned to the bike – and recommends indoor cycling to all the Hyrox athletes at her club. “There’s a value to the bike whether you’re a beginner, intermediate or advanced athlete putting in many hours of training,” she confirms.

“If you’re not used to running, all your runs need to be easy at first, but I have no problem telling a beginner to do 20 miles on a bike in a week. We can hit all energy systems aerobically and anaerobically, while also working muscular endurance, without worrying as much about wear and tear.”

“When we’re cycling at 85–90 RPM, it translates to the cadence our athletes will want to hit when they’re running”

Specificity in training

On that note, Lora is clear that indoor cycling isn’t only good for aerobic training. It also plays an important role in building the muscular endurance and power you need for a Hyrox event.

“I noticed I lost some muscular endurance when I was doing all that running,” she comments. “It took the bike to get it back. People associate indoor cycling with cardio classes, but there’s so much more to it than that: you can be very specific with what you’re trying to achieve. I’m now the strongest I’ve ever been on a bike. It’s an invaluable tool.”

Hill work is where much of this specificity lies: sustained climbs with heavy resistance load the legs for minutes at a time, building the kind of muscular endurance that transfers directly to Hyrox’s loaded stations.

At Revd, around 30 per cent of any class is spent on hills – and for Hyrox athletes, there’s an intriguing, Hyrox-specific biomechanical comparison, says St Marc.

“The forward body angle, hands positioned out in front, sustained leg drive and resistance under load, driving down with the heel, pushing, leaning into it. That motion of climbing a hill on the bike is so similar to the Hyrox sled push,” she says. “When I competed, I really leant into that ability to power through something resisting my body for sustained periods.”

It isn’t a perfect replica, of course, but it’s a vivid image. Indoor cycling isn’t just developing fitness in the abstract. In some cases, it may be rehearsing elements of the physical demands Hyrox athletes will face on race day.

Rout3 certainly uses a number of cycling techniques that have direct relevance to Hyrox, with one of Lora’s favourites being what she calls high-intensity continuous training (HICT): “In a seated position, you ride at the heaviest gear you can sustain while maintaining your RPMs between 30 and 40. If you can hold that for five, 10, 20 minutes, that’s developing endurance in your power.

“With Hyrox, you’re switching between exercises every couple of minutes. That’s matched by the variety within a cycling class.”

“Where that translates to Hyrox is being able to maintain hard, powerful movements for longer periods of time. Pushing a sled, immediately running, then pulling a sled… Hyrox involves a series of muscularly-demanding stations on top of the running, all of which demand force production under fatigue.”

She also highlights something subtler Rout3 works on with its athletes: cadence. “When we’re cycling at 85–90 RPM, moving our feet faster at a lower gear, it translates to the cadence our athletes will want to hit when they’re running.

“Optimal running cadence is around 170–190, so if you can keep it around 85 to 90 on the bike, that’s going to translate well to the running form you’re aiming for.”

Switching energy systems

With one of Hyrox’s defining features being the frequent changes in activity – heavy muscular work, sudden heart rate spikes, then a return to running before the whole cycle starts again – variability in training is also important. You aren’t just training to be aerobically fit or strong in isolation; you’re training to become good at moving between the two.

And once again, indoor cycling delivers, says Penrose: “With Hyrox, you’re switching between exercises every couple of minutes. That’s matched by the variety within a cycling class. A heavy hill prepares you for weighted lunges. Sprints prepare you for the burpees and the running.”

“Why are we going from a hill straight into a sprint? Because you’re tired and I want to challenge you while you’re tired.”

The key is to think beyond generic ‘cardio’ and ask what quality you’re trying to develop, Lora explains. Is it aerobic capacity? Threshold tolerance? Muscular endurance? Power under fatigue? Cadence? Recovery? Once you know that, your indoor cycling programming can become much more precise.

And so both coaches favour more than just steady-state riding. Yes, there’s a place for zone two work and threshold efforts, particularly if an athlete’s wider programme already includes a lot of high-intensity Hyrox training. As Penrose explains: “You have to look at the full picture of your training so you aren’t continually working your body in the same way.”

But there’s also a case for deliberately building in transitions on the bike: moving from heavy hills to fast efforts, from seated grinding climbs to short sprints, from long sustained work to bursts of power.

The goal: to get riders better at producing effort when the body is under strain, rather than only when it feels fresh.

Training tired

This is where Abby Claus, indoor cycling instructor at Revd and a high-level Hyrox competitor, brings a really interesting dimension to the discussion.

For Claus, one of indoor cycling’s greatest benefits has nothing to do with whether it replicates a Hyrox movement pattern, nor whether the resistance on the bike perfectly matches the force demands of a sled. It’s about mental preparation for race day.

“You can prepare physically all you want,” she explains, “but ultimately it’s going to be a mental challenge as well.”

It’s why she deliberately structures her training so that strength work comes after cycling. “Going into the exercises when I’m feeling my best isn’t representative of how I’m going to feel during the race. You’re never going to approach the skierg, rower or burpees feeling rested in zone one – that’s just not how Hyrox works. The first thing you do is run a kilometre.

“So, I make sure I do my workouts in a compromised state: indoor cycling first, tiring me out aerobically before the functional work, so my body is challenged similarly to how I’ll be during the actual race.”

Her go-to sessions at Revd include long two-part climbs, heavy resistance pushes and upper-body tracks that demand continuous work for five to seven minutes at a time. The hand weights used in these tracks may be light – 2–3lbs, not the sort of load you face in Hyrox – but for Claus, that isn’t the point. The point is the uninterrupted effort, the time under tension and the need to keep going when the discomfort starts to bite.

She makes sure her riders understand this, too. “Why are we going from a hill climb straight into a sprint? Because you’re tired and I want to challenge you while you’re tired,” she says, describing how her cycle classes can become a rehearsal space for the internal dialogue of Hyrox racing: the point at which the body wants to back off, but the athlete has to keep going.

“By measuring outputs such as VO2 max, peak power and maximum minute power, we can prescribe targeted training”

She talks about members carrying mantras from her classes into competition – “You are always stronger than your hardest moments” and “This moment is temporary” – and about athletes learning to trust their bodies because they’ve repeatedly experienced challenge in the studio and come through it.

Data-based programming

Taken together, the evidence clearly points to indoor cycling as a powerful way to develop the aerobic engine, muscular endurance and repeatable power that Hyrox demands. At UK-based Everlast Gyms, those qualities are measured objectively before training even begins.

Under the leadership of managing director Dan Summerson and with Faisal Abdalla – Global Hyrox MC – as head of Everlast Gyms’ Hyrox Performance Centers, the business has built what it describes as a race-day-accurate training environment. But the element that really sets it apart from a well-equipped gym floor is its commitment to removing guesswork from the preparation process.

“Wattbike gives us access to objective performance data,” says Summerson. “By measuring outputs such as VO2 max, peak power, maximum minute power and pedal efficiency, we can identify an athlete’s strengths, weaknesses and training priorities.

“This allows our coaches to prescribe targeted training interventions, whether that’s improving aerobic capacity, developing race-specific power, addressing muscular imbalances or increasing overall performance.”

“Used intelligently, indoor cycling can help build the engine, resilience and confidence that Hyrox demands”

Two bike-based tests are of particular importance in this respect. The first is the aerobic power test, which tracks VO2 max progression and heart rate kinetics. With re-testing offered every eight to 12 weeks, coaches can monitor whether athletes are producing more power at lower heart rates over time, a key indicator of improved aerobic efficiency and race durability heading into a Hyrox event.

The second is an anaerobic power test, which measures fatigue factor and power decay under load: how well an athlete maintains output when fatigued. This has obvious transfer to stations such as sled push/pull, burpee broad jumps and wall balls, where maintaining force production late in the race is critical.

“For Hyrox athletes, success requires a blend of endurance, strength and repeatable power output,” says Summerson. “Our combination of data-driven testing, expert coaching and structured programming allows us to deliver a more personalised training experience and help members achieve better results.”

The bottom line

Hyrox is, on the surface, an event built around running and functional strength. But look more closely and the case for indoor cycling as a cornerstone of preparation becomes not just compelling but obvious.

Indoor cycling builds the aerobic engine. It develops muscular endurance and power. It protects the joints that running wears down. It allows athletes to train at intensity more frequently and recover more effectively. It can replicate the feeling of arriving at each station already tired. And it conditions the mind, as much as the body, to keep going when everything is telling you to stop.

And so the experts are clear: despite never featuring on the race floor itself, indoor cycling absolutely deserves a place in any Hyrox training schedule. Used intelligently, it can help build precisely the engine, resilience and confidence that Hyrox demands.