Guides · Research-based comparison
Treadmill or Exercise Bike
Neither machine is inherently better for weight loss — the one you actually keep using wins, and adherence research consistently shows most people stop within weeks regardless of equipment. If forced to choose on specs alone: a treadmill burns marginally more calories per minute and is the only one that trains running; an exercise bike is quieter, gentler on your joints, and easier to sustain for longer sessions — which matters more if consistency, not theoretical burn, is your real obstacle.
This is a research-based comparison
We have not bought or hands-on tested a treadmill or exercise bike for this page. It's built from manufacturer specifications, UK retail pricing checked against live listings in August 2026, and published exercise-science and adherence research — not our own measurements. No product here carries one of our own numeric scores, because a score requires hands-on testing under Test Bench v1.0, which hasn't happened for this category yet.
Treadmill or exercise bike: the facts side by side
Price ranges below are illustrative — anchored to real UK listings checked in August 2026 (Opti, Decathlon, JLL models) rather than a single guaranteed price. Always confirm current stock and price before buying.
| Factor | Treadmill | Exercise bike |
|---|---|---|
| Calories per minute (matched effort) | Roughly 8–11 kcal/min running | Roughly 8–10 kcal/min at hard effort — close enough that consistency matters more |
| Joint impact | Higher — footstrike loads knees and hips | Very low — seated, no impact |
| Noise in a flat | Motor plus footstrike — the louder of the two | Quieter — mainly resistance/flywheel hum |
| Typical footprint | ~150–213cm × 61–91cm, plus running clearance | Considerably smaller — most models under 150cm long |
| Typical UK price | ~£250–£700+ | ~£100–£280 (upright/recumbent) |
| What it actually trains | Walking, running, incline hill work | Seated cardio endurance; recumbent is easiest on the lower back |
Choose a treadmill if… choose an exercise bike if…
Choose a treadmill if
- You want to walk or run, not just pedal — the movement pattern motivates you more.
- Your joints tolerate impact and you want the higher achievable intensity.
- You have a room where noise and floor space aren't tight constraints.
Choose an exercise bike if
- You live in a flat and noise for neighbours below is a genuine concern.
- Knee, hip or back issues make impact uncomfortable.
- Floor space is limited, or you want the lower entry price.
Which burns more calories — and does it matter for weight loss?
On paper, treadmill running has a small edge: commonly cited figures put running at roughly 8–11 kcal/min against roughly 8–10 kcal/min for hard stationary cycling. That's a modest gap, and it closes or reverses easily if you ride the bike harder or for longer than you'd run.
The gap that actually matters for weight loss isn't calories per minute — it's whether you keep showing up. Research into unsupervised exercise programmes has found dropout reaching roughly half of participants within around two months and the large majority within six, a pattern that shows up across many different exercise formats, not just cardio machines specifically. Against numbers like that, a small per-minute calorie advantage on paper is far less important than choosing the machine you'll actually use consistently — adherence beats theoretical burn, and it isn't close.
Which is easier on your joints?
An exercise bike wins this comparison clearly. Cycling is a seated, supported movement with no footstrike at all, so there's no repeated impact for your knees, hips or lower back to absorb. Treadmill walking or running, by contrast, delivers a footstrike every stride — research on running mechanics has found forces at the knee reaching two to three times body weight per step.
That doesn't make a treadmill the wrong choice for everyone: plenty of people run and walk for years without joint problems, and load-bearing impact exercise has its own bone-density benefits a bike doesn't offer. But if joint comfort is the deciding factor, or you're recovering from an injury, the bike is the lower-risk option.
Which will bother your downstairs neighbours less?
An exercise bike, and it isn't close. A treadmill's noise comes from two sources — motor hum and footstrike impact — and it's the footstrike, not the motor, that neighbours in flats and terraces consistently report as the actual problem, because low-frequency impact noise travels through floor joists far more effectively than a motor's whir. An exercise bike has no footstrike at all: its noise is limited to a quieter resistance mechanism, whether that's magnetic, friction, or a light flywheel.
If you live in a flat with people below you, this is arguably the single biggest practical factor in the whole comparison — bigger than calorie burn, price, or footprint — because it's the one that determines whether you can actually use the machine at the hours that suit your schedule.
Which takes up less space in a UK flat?
An exercise bike again, generally by a clear margin. A typical treadmill runs around 150–213cm long and 61–91cm wide, and needs genuine clear space behind and beside it to be used safely at running speed — space you can't repurpose for anything else while it's set up. Most upright and recumbent exercise bikes are considerably more compact and don't carry that same safety-clearance requirement, so they fit into corners and smaller rooms a treadmill simply can't.
Which is the better buy at UK prices?
Exercise bikes are the cheaper entry point across the board. Basic upright models start from around £100 (Opti's folding magnetic exercise bike), with a decent recumbent bike around £180 (JLL's RE100). Treadmills start meaningfully higher — roughly £250–£300 for a basic folding motorised model (Opti), rising past £700 for a smart, connected treadmill like Decathlon's Run500.
That price gap tracks the extra engineering a treadmill needs: a larger, more powerful motor, a longer running deck, and — on most models — a folding mechanism, all of which add cost and long-term maintenance risk that a bike's simpler mechanism largely avoids. If budget is the deciding factor on its own, the exercise bike wins outright.
Frequently asked questions
What is better, a treadmill or an exercise bike?
Neither is inherently better — it depends on what would actually get used. A treadmill burns marginally more calories per minute at matched intensity and is the only one that trains running. An exercise bike is quieter, easier on your joints, and more comfortable to sustain for longer sessions. If you're genuinely undecided, weight it towards whichever one you're less likely to abandon after a few weeks, since that outcome affects your results far more than either machine's specifications.
Is a treadmill or exercise bike better for weight loss?
The calorie-burn difference between the two, effort for effort, is small — commonly cited figures put treadmill running at roughly 8–11 kcal/min against roughly 8–10 kcal/min for hard stationary cycling. What actually predicts weight-loss results is adherence: research into unsupervised exercise programmes consistently finds dropout rates reaching well over half within a few months, regardless of equipment. The machine you'll use three times a week for six months beats the one with the marginally higher theoretical burn that gathers dust after week three.
Which is quieter for a flat, a treadmill or an exercise bike?
An exercise bike, clearly. A treadmill combines motor hum with a footstrike thud on every stride, and that thud — not the motor — is what travels through floors and bothers neighbours below. An exercise bike is seated and has no footstrike at all, so its noise is limited to a much quieter resistance mechanism.
Do treadmills or exercise bikes take up more space?
Treadmills take up meaningfully more space. A typical treadmill runs around 150–213cm long and 61–91cm wide, and needs clear space behind and beside it to run safely at speed. Most upright and recumbent exercise bikes are considerably more compact and don't need that same safety clearance, which matters in a small UK spare room or flat.
Which burns more calories, a treadmill or an exercise bike?
At matched perceived effort, the two are close — treadmill running edges ahead per minute, largely because running is inherently higher-impact and higher-intensity than seated cycling. But a bike ridden harder or for longer can close or exceed that gap easily, so the honest answer is that the difference is small enough that consistency decides the outcome, not the machine.
See our full cardio machines hub for individual treadmill and exercise bike picks, or browse every buying guide we publish.
Update log
First published. Research-based comparison built from published UK retail pricing, manufacturer specifications and general exercise-science and adherence research — no hands-on testing has taken place.