The best HIIT classes in London compared: Barry's, F45, 1Rebel, Blok and Rumble — formats, vibe and how to pick the one you'll stick with.
London has arguably the deepest HIIT scene in Europe: red-lit treadmill bootcamps, functional-circuit franchises, studios staged like nightclubs and rolling circuits you can join every ten minutes. We run one of them — the Re.HIIT circuit at Rumble — so this isn't a neutral review site, and we won't pretend it is. But we train in this city too, and the honest answer to “what's the best HIIT class in London?” is that it depends what you want from your forty-odd minutes. This guide covers what genuinely separates a great HIIT class from a forgettable one, how London's best-known options compare — ours included — and how to choose between them.
What separates a great HIIT class from a sweaty one
HIIT — high-intensity interval training — alternates short bursts of near-maximal effort with planned recovery. That structure is the whole point: the intervals let you work at intensities you couldn't sustain continuously, and the recoveries let you repeat them. Done badly, HIIT becomes forty minutes of random exercises at medium intensity with no actual intervals — tiring, but not training. Whichever studio you're weighing up, hold it against five things:
- Real intervals: work and recovery should be deliberate and timed, not just a fast-paced class. If everything is medium intensity, it isn't HIIT.
- Programming that changes on purpose: identical every week and your body adapts; randomly different every day and you can't measure progress. The best studios rotate movements inside a consistent structure.
- Coaches on the floor: real intensity is where technique breaks down. You want trainers correcting form and scaling movements mid-class, not presenting a playlist from the front.
- Honest scaling: “all levels welcome” should be built into the format — effort-relative stations let a first-timer and a competitive athlete train side by side, each at their own ceiling.
- Recovery built in: the adaptation happens between sessions. Good programming leaves room for lower-intensity days rather than selling you intensity seven days a week.
The best HIIT class in London is the one you'll still be going to in March.
London's best-known HIIT classes, compared
Every studio on this list is genuinely good at what it does — they're built around different priorities, and the right one depends on which priority is yours. A note on fairness: we've described each studio's format, schedule and vibe as they present them, with no scores and no rivals' prices quoted (they change too often — check each studio's own site). Ours are listed because we can vouch for them.
Barry's — the original treadmill-and-floor bootcamp. The brand that made boutique HIIT famous, with studios across London. Classes alternate treadmill intervals with weights-based floor work in its signature red-lit rooms, driven by big music and big-personality trainers. If you love running and want the loudest, best-known version of the treadmill-plus-floor format, it remains the benchmark — and it's exactly the format of our own Re.Run (Run & Lift) classes at Dalston.
F45 — 45-minute functional circuits, everywhere. A global franchise with studios all over London, built on 45-minute functional circuits: timed stations, screens demonstrating each movement, trainers circulating, programming that changes daily. The format is deliberately the same in every location, and that consistency is the appeal — a community-minded circuit near home, near work and anywhere you travel. It's also exactly the territory of our own Re.HIIT circuit, with two differences: at Rumble a new class starts every 10 minutes rather than on a fixed timetable, so it's a lot more flexible, and the session runs longer than the clock suggests — 40 minutes on the circuit, closer to 50 once you include the warm-up. At £25 a class and Rumble memberships from £49/month, it's typically the cheaper way in too.
1Rebel — HIIT as theatre. London-born and unapologetically theatrical: dark rooms, serious sound systems and a production feel closer to a night out than a gym class. Reshape is its treadmill-and-floor HIIT concept and Ride its take on spin, staged across central London studios. If atmosphere is what carries you through the final interval, nobody stages it bigger. The workouts themselves have direct Rumble equivalents: Reshape maps to Re.Run (Run & Lift) and Ride to our Re.Cycle spin formats, both at our Dalston studio.
Blok — design-led classes in East London. Founded in East London and known as much for its beautifully designed spaces as for its training, Blok runs coached classes across HIIT, strength, boxing and mobility. The vibe is calmer and more considered than the big-production studios — closer to a design studio than a nightclub, and better for it if crowds and strobes aren't your thing.
RUMBLE — a new class every 10 minutes. Our own format, so weigh the bias — but it was built around the thing every on-the-hour timetable gets wrong: your schedule. Re.HIIT is a 40-minute coached circuit mixing cardio bursts — treadmills, bikes, sleds — with functional strength stations. The workout changes every day of the year, and a new class starts every 10 minutes, all day — miss your train and you've missed ten minutes, not the workout. Coaches work the circuit floor rather than the front of the room, and it runs at both our studios: Dalston (E8) and Fitzrovia (W1W). A single class is £25, and memberships start from £49/month with the Off-Peak plan at Fitzrovia — Re.HIIT Unlimited is £119/month at any studio.
How to choose between them
Match the studio to whatever actually gets you training. If a famous name and a packed, high-energy room push you harder, start with Barry's or 1Rebel. If you want one consistent format near home, work and everywhere in between and if the deciding factor is coaching plus a schedule that bends around real life — a class every 10 minutes instead of on the hour — that's the exact problem Re.HIIT at Rumble was designed to solve.
Two more honest tips, whichever way you lean. First, judge a studio on its coaching rather than its feed — a great trainer will scale every station to you within one class, and ours also coach one-to-one if you want a head start. Second, think about recovery before you buy any unlimited plan: two to four HIIT sessions a week with lower-intensity work between them beats seven straight days of intensity, which is why our Dalston studio pairs the circuit with yoga and Pilates and Reformer Pilates alongside spin and treadmill classes.
Put us to the test
Wherever you land, London's HIIT scene rewards showing up. Pick the class that fits your week, hold it to the checklist above — and if that turns out to be us, there's a class starting in the next ten minutes.
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