Glossary
Air resistance
Resistance from a fan that gets harder the faster you push. Effective for intervals but loud, so check noise before using one above neighbours.
Air resistance comes from a fan blade spinning inside a housing, so the harder and faster you pedal or pull, the more air it has to push and the more resistance you feel. There is no dial to set, which makes it naturally responsive for interval work where effort changes second to second.
The same fan that makes air resistance effective also makes it one of the loudest resistance types, both from the whooshing air and from the shroud vibrating, which is a real concern in an apartment with neighbors below or beside a workout space.
When buying, look for models with an enclosed or adjustable fan shroud, since some designs reduce the noise without changing the resistance feel much. Check the footprint too, as fan housings tend to be wide. A common mistake is buying an air bike for apartment HIIT without checking its noise rating first, then discovering morning intervals wake people nearby. Scheduling harder interval sessions for daytime hours can help even after the bike is already in the room.