'This just knows so much more than a human ever could': Meet CoachCube, the intelligent AI personal trainer that lives inside a Tron-style box room

Fitness in 2026 feels like it's pulling in two very different directions at once. On one hand, artificial intelligence is continuing to colonise the gym floor — largely from AI-powered coaching apps, but also via new analysis of data points from wearables, gently nudging you off the sofa based on sleep and recovery data collected from the likes of the best smartwatches, best smart rings or your form factor of choice. Whether you like it or not, your next workout will probably have an algorithm involved somewhere, requiring zero element of human interaction.

Yet, should you scroll through any city-based social feed right now, you'll find a counter-movement in full swing. All year round, run clubs are booming. People are lacing up not just for the miles, but for the social scene, the post-run coffee catch-up and the sense of occasion of ticking something off early doors. Fitness, for a growing number of people, is the new social life.

So where does that leave a product like CoachCube, an AI-powered training ‘cube’ that puts you alone in a room with a cable machine, projection screens, and a virtual coach that watches your every rep across dozens of moving data points?

It sounds, on paper, like a run-clubbing extrovert's worst nightmare, but on the flipside, it could be the exact product many people need — personalized coaching, in a focused environment and weights that respond directly to your strength. No sweaty gym bros necessary.

I headed to CoachCube in central London to see whether this new method, and others like it, could be the future of training.

Squaring the circle

I’m someone who thrives on the social element of workouts, which makes me, on paper, exactly the wrong person to be impressed by a training cube designed for solo workouts. And yet, for the many put off by busy gyms, overstimulating environments and eye-watering personal training fees (especially in big cities like my native London) I completely understand what CoachCube is going for. Simply: it’s bespoke coaching, in private, at a cheaper rate (50%, more or less) than a personal training session in nearby gyms.

Walking into the Cube, you can immediately see the appeal. It’s you, your training guide — broadcast onto three surrounding projection screens, you can’t miss it — and the cable machine, which is powered by an electric motor providing up to 200kg of resistance a little like the Gym Monster 2, another AI-powered training tool, or some of Technogym's more advanced fitness tech. As someone who finds cluttered training environments (or, in the case of my local gym, machines almost always in a state of repair) a stressful place to be, CoachCube’s minimal design is surprisingly welcoming, as it keeps me focused on the avatar that walks me through each of the four movements I’m trialling.

At the start of each new exercise, the avatar first shows me the ideal form for each movement and the muscle groups I’ll be working, before moving into a warm-up with no added weight. Using a fish-eye lens to my left, the camera tracks my form over multiple data points and, after three reps of warm-up, ‘clicks’ in with the recommended resistance for my strength profile.

I work through three sets of bicep curls and tricep extensions, using two different attachments that click into the machine, before moving on to barbell overhead presses and barbell back squats.

After each set, I get a quick 10- to 15-second rundown of my form, which is then scored out of 10 (my highest was 8.6, which I’ll take) and used as a reference point for the AI to give me pointers for the upcoming set. During the tricep extensions, for example, CoachCube’s AI trainer reminded me to keep my shoulders pinned by my body for optimal tension and, during the barbell squats, to hit greater depth at the bottom of the move. It’s no secret that gym-goers are also trying to beat their last set and I found this score system to be a welcome reminder to keep my reps honest. Something we all could do more of.

Using AI for good

To access CoachCube, all users need to do is pre-book a slot (£30,9 approximately $ / AU$ , an hour with discounted packages available), turn up and get to work. The AI does the rest. As CoachCube’s founder Will Dean explains, later models of the CoachCube system could eventually learn to recognise various signs of strain through biometrics and diary entries housed in your smartphone or smartwatch — how much you slept last night, for example, or if you’ve recently had a long-haul flight — and tailor your workout according to the condition in which you’ve arrived.

Dean theorises that this smartphone will “immediately sync, and it would say, 'I've just looked at your data, it looks like you went for a run yesterday and your readiness score isn't 100%, you've just been travelling with work and you did a big run yesterday,'” he explains. “It will explain that ‘this is not going to be a PB day, and the aim today is to match our workout to your readiness score.'”

That level of contextual awareness is only half the picture. Once you're inside and moving, CoachCube is pulling from multiple data streams simultaneously and adjusting on the fly. "It's watching you," says Dean. "There's a camera vision model that creates all these nodal points, basically creating a skeleton of you, and it knows how tall you are.

“Because [the cube is] a controlled environment, it knows exactly what's on the wall behind you,” he continues, “so there's none of the confusion you get with app-based solutions where someone walks by and throws everything off."

Alongside the visual data, the system is also reading resistance in real time through the motors themselves. "If you get two-thirds through a set and you're struggling with your left arm but not your right, it will identify that weakness and adjust in real time," Dean explains. There’s always the comparatively old-fashioned option, too.

Though I didn’t get to try this with the current model, Dean assures that you could eventually “have a verbal dialogue” with it — just like you would with an Amazon Alexa speaker.

"The best PT in the world is still somewhat reliant on the human being saying 'that was hard' or 'that was easy.' But this just knows so much more than a human could ever know, because it is the weight."

The future of fitness

For all its technological ambition, Dean is keen to stress that CoachCube isn't a death knell for the personal training industry. "If you know what you're doing and you're willing to adapt, this really should be something that grows your business," he says, envisioning a model where PTs design programmes for clients to execute independently in the cube between sessions.

Beyond the gym floor entirely, the use cases are genuinely compelling: Dean has his sights set on hotels, airport lounges and retirement homes — anywhere, essentially, that people find themselves time-poor, space-limited, or simply underserved by whatever passes for a fitness facility nearby.

It's a convincing pitch. Having spent an hour inside one, it was never about CoachCube replacing the pre-dawn run club or a functional fitness class under the lights — nor should it try. For the version of me that exists on a rainy evening, short on time, shorter on motivation and unwilling to perform a single wobbly squat in front of a gym full of strangers? That version of me would book again without hesitation.

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