Exercise Bike vs Treadmill for Home Workouts

Walk a small apartment with a tape measure and the choice changes shape. The usual “low-impact versus better calorie burn” framing decides nothing, because both claims depend on numbers the comparisons never give you. This guide gives them: the force a running stride drives into your floor, what a resistance number has to mean to be real, and how a bike watt and a treadmill speed line up in actual intensity. The specs are from manufacturer pages, and the verdict is per apartment, not “depends on you.”

The short answer, by who lives below you

Three lines settle most cases. A shared floor with an occupied unit below: bike. A dedicated room, or nothing occupied below: either, pick by goal. Weather-blocked or building-blocked with no stairs to use: a folding treadmill, bought with the safety stop and the noise in mind. The variable no leader leads with is the neighbor, so start there.

What “high impact” actually weighs

“High impact” is an adjective until you weigh it. On a force plate, running drives a peak vertical ground reaction force of about 2.5 times body weight per footfall, measured at 2.51 times at 11 km/h and 2.62 times at 13 km/h. For an 82 kg runner that is roughly 200 kg of peak force per step, and running cadence lands around 160 to 180 steps a minute, so about 10,000 foot contacts an hour. A bike puts none of that into the floor; pedalling is a smooth, seated load.

That force, not the motor, is what the neighbor feels. Airborne motor noise (the dB on the box) and structure-borne impact are different problems: the impact travels through joists and reads as a recurring thump in the unit below, while a bike’s magnetic resistance is near silent. The static weight of the two machines is similar and both sit far under a normal floor’s rating, so this is about repeated impact, not about the floor holding the machine. The structure-borne primer is in quiet apartment workouts and floor protection is in home gym flooring.

What a resistance number actually means

“Magnetic resistance, levels 1 to 32” is marketing until something calibrates it. German equipment standards do. Under EN 957-1/5 and DIN 32932, a Klasse A ergometer must let you set pedalling resistance to at least 250 watts, with the displayed power accurate to within 5 percent up to 50 W and 10 percent above it; gear in this class is approved for medical and therapeutic use. Flywheel mass sorts the lower tiers: Klasse B needs a flywheel of at least 5 kg, Klasse C less than that. Klasse A is defined by watt accuracy, not flywheel weight.

The practical filter: a watt-controlled bike gives you a repeatable number you can train against and compare week to week, while an uncalibrated “level 18” means nothing across two machines. If progress tracking matters, ask whether the bike reports real, accurate watts, not just a level.

Verified specs for six representative models

Direct from manufacturer pages; named for spec representation, not endorsement.

Model	Footprint (LxWxH)	Folded	Weight	Max user	Resistance / motor	Speed / incline
Schwinn IC4 (bike)	54.6 x 30.7 x 51.8 in	n/a	113.6 lb	330 lb	100 magnetic levels	n/a
Echelon Connect EX-3 (bike)	55 x 20 x 55 in	n/a	104 lb	300 lb	32 levels, 28.6 lb flywheel	n/a
Echelon EX-5s (bike)	58 x 21.5 x 61 in	n/a	124 lb	300 lb	32 levels, 28.6 lb flywheel	n/a
NordicTrack S15i (bike)	55.75 x 22 x 61 in	n/a	~180 lb	350 lb	22 digital levels	-10% to +20% incline
Sole F63 (treadmill)	77 x 35 x 67 in	50 x 35 x 72 in	224 lb	325 lb	3.0 HP motor	0-12 mph, 0-15%
Horizon T101 (treadmill)	71 x 34 x 57 in	46 x 34 x 61 in	~180 lb	300 lb	2.5 HP motor	0-10 mph, 0-10%

Two things stand out: treadmills are larger in every dimension and 50 to 100 pounds heavier, and the NordicTrack S15i is the only bike with a built-in incline, which pushes cycling closer to incline-walking cardio. The Sole F63’s 3.0 HP motor and 12 mph top speed leave headroom for real running; the Horizon T101 is a walker’s machine first.

Matching intensity honestly: watts vs mph in MET

Calories per minute change with body size; METs do not, which makes them the honest way to compare a bike effort with a run. From the 2024 Adult Compendium of Physical Activities:

• Stationary cycling 101-125 W = 6.8 MET; 126-150 W = 8.0 MET; 151-199 W = 10.3 MET.
• Running 6 mph (10 min/mile) = 9.3 MET; 7 mph (8.5 min/mile) = 11.0 MET.

Read together, a hard-but-sustainable bike effort (around 150-200 W) sits in jogging territory at zero joint cost. The WHO asks adults for 150 to 300 minutes of moderate activity a week, and either machine reaches it; the real question is which one you will stay on for that many minutes.

Apartment scenario matrix

Scenario	Pick	Reason
Studio under 30 m2, neighbors below	Bike	Footprint and ~2.5x-body-weight impact both push the wrong way
30-60 m2 mid-floor, neighbors above and below	Bike (treadmill only in an isolated zone)	Mid-floor is the worst case for impact noise
Top floor or over commercial/empty space	Either	Less transmits with no occupied unit below
Dedicated home-gym room	Either	Pick by goal, not space
Sleeping baby or shift worker below	Bike	A treadmill’s impact thump cannot be mat-fixed

The deeper apartment context is in the stay-active-in-a-small-apartment guide.

A named apartment example, and the verdicts

A 42 m2 mid-floor apartment, hardwood, downstairs neighbors with school-age kids, no winter outdoor walking. The original plan was a Sole F63 in the living room. It did not survive the numbers: the 77 x 35 in footprint left no walkway even folded, and at roughly 2.5 times body weight per stride into hardwood, 6 a.m. training would reach the unit below every step. The swap was a Schwinn IC4: about 110 lb less mass on the floor, 22 in less length, and the entire impact load removed. The honest result is four to five bike sessions a week that would not have happened on a treadmill the owner was afraid to turn on.

Verdicts by use case: small apartment or shared wall, bike; dedicated room, either, picked by goal; cardio-only goal, bike, because zero joint wear matters more at year five than week three; no stairs and weather-blocked, a treadmill makes sense (Horizon T101 for walkers, Sole F63 for runners) bought with the walking pad vs treadmill safety check in mind. The strength half of a home setup is in the small home gym setup guide.

If you have a medical condition, an injury, ongoing pain, pregnancy-related considerations, or limited mobility, talk to a clinician before a new cardio routine.

Common questions

Which is better for bad knees, a bike or a treadmill?

The bike, by mechanism: cycling is a seated, near-zero-impact load, while running drives about 2.5 times body weight through each leg thousands of times a session. Most people keep training through minor knee complaints on a bike that would stop a treadmill routine.

Is a treadmill too loud for an apartment?

Walking is manageable; running is the problem, and it is impact, not motor noise. A 2.5-times-body-weight stride transmits through the floor regardless of the dB rating, so an upper-floor unit with neighbors below favours the bike.

How do I compare a bike level to a running speed?

Use METs, not calories. About 150-200 watts on a bike (roughly 8-10 MET) lines up with jogging at 6-7 mph (9.3-11 MET), at no joint cost. A bare “level 18” tells you nothing unless the bike reports accurate watts.