When you're riding your bicycle outside, wind resistance increases exponentially according to your speed. That’s why it is more than twice as difficult to ride at 20 mph than at 10 mph.

However, not all bike trainers create resistance the same way. Here’s a brief breakdown to help you choose which will work best for you.

LINEAR resistance means that when you pedal faster or shift gears on your bike, the resistance changes proportionately to your change in speed. This type of resistance feels least like riding outside.

ADJUSTABLE resistance allows you to choose from various levels of linear resistance on the trainer.

PROGRESSIVE resistance is much more “true to the road” because when you pedal faster or shift gears, the resistance increases just as it would out on the road.

CONTROLLED resistance offers you the ability to predefine workouts with varying degrees of resistance that are managed by a compatible head unit (like the PowerTap Joule GPS), the VirtualTraining app, or other compatible apps. The trainer then adjusts as you pedal.

Not every trainer offers the same type of resistance or real-road feel. Here’s a brief overview to help you make your pick.

WIND trainers are based on the simple concept that the faster you pedal, the more resistance you create in the fan-like flywheel—in other words, the resistance is progressive. Keep in mind that noise level also rises in relation to your speed.

MAGNETIC trainers offer five adjustable levels of linear resistance, which you can control from a handlebar-mounted shifter. Magnets inside the flywheel ensure that your ride stays smooth and even throughout your workout.

PROGRESSIVE MAGNETIC trainers are also designed for smooth rides. However, the difference is that as you increase your pedal speed, the resistance increases exponentially. Simply shift gears the same as you would outside.

FLUID trainers are PowerTuned* to provide smooth, realistic accelerations and inertia for an extremely realistic road feel. Fluid resistance units are also exceptionally quiet at every speed.

ELECTRONIC trainers are equipped with PowerTap technology, giving you precise measurement and feedback. This means you can create customizable workouts and have precise control over your training zones and slope. The controlled resistance is best when paired with VirtualTraining.

ELECTROMAGNETIC trainers use resistance that is created by running an electrical current through a series of windings around a magnetic core. Fluctuations of the magnetic field are controlled by the amount of current running through the windings and can be changed rapidly or stopped completely by turning off the current. This results in precise and very rapid control of the trainer's resistance, making the experience more realistic than permanent magnets used in non-electronic trainers.

*PowerTuned: Each trainer's power curve is created using PowerTap technology to produce the widest range of resistance at real world speeds. Each resistance unit is also tested using a PowerTap to ensure a consistent power curve from one to the next.