Air Bike (Fan Bike)

The air bike (fan bike — e.g., Assault/Echo bike) uses a large fan as the resistance: the harder you push (legs) and pull/push (arms via moving handles), the more air the fan moves and the harder it pushes back. Resistance is therefore self-scaling and effectively unlimited — you can never "spin out" the way you can on a magnetic bike.

What it's good for: all-out intervals and sprints (hiit, sit) and short hard efforts where you want maximal output (calories/time or distance targets). The moving handles make it a full-body effort (legs + arms + lungs).

Pros: infinite, instant, self-scaling resistance perfect for intervals; full-body; low impact; honest output metrics (calories/watts) for work-rest-ratio interval design. Cons: uncomfortable and notoriously punishing at high intensity (which is the point); loud fan; less suited to long steady aerobic work than an upright/spin stationary-bike; bulky.

• Fan resistance scales with effort → effectively unlimited, self-limiting load.
• Moving handles = full-body (legs + arms); low impact.
• Best for all-out intervals/sprints and short hard efforts; honest calorie/watt output.
• Loud, punishing at high intensity; less ideal for long steady-state.

• hiit / sit — its natural interval/sprint home.
• work-rest-ratio — output metrics guide interval design.
• stationary-bike — better for steady aerobic work.
• rowing-machine — another full-body, self-scaling option.