A typical class involves a single instructor at the front of the class who leads the participants in a number of different types of cycling. The routines are designed to emulate terrain and situations encountered in actual bicycle rides, including hill climbs, sprints and interval training. Coasting downhill, however, is not simulated. The instructor uses music and enthusiastic coaching to motivate the students to work hard.
Each spinner in the class can choose his/her own goals for the session. Some participants choose to maintain a moderate, aerobic intensity level, while others drive their heart rates higher in intervals of anaerobic activity. It can be difficult to stay at the moderate level in a class that is geared towards more intensity. If spinning is not done correctly, injuries can occur; problems with the lower back and knees are most common.
Spinning classes generally use specialized stationary bicycles. Features include a mechanical device to modify the difficulty of pedalling, specially-shaped handlebars, and multiple adjustment points to fit the bicycle to a range of riders. The pedals are equipped with toe straps to hold the foot to the pedal, enabling powerful upstrokes. They may also have cleats for use with specialty bicycling shoes. These bicycles do not have the electronic features found on some models of stationary bicycles.
The difficulty of the spinning workout is modulated in three ways:
1. by varying the resistance on a flywheel attached to the pedals. The resistance is controlled by a knob, wheel or lever that the rider operates, causing the flywheel brake (a common bicycle brake, a friction wheel, a magnetic eddy-current brake, a viscoelastic fluid brake, or a strap running around the flywheel) to tighten. Tightening the brake makes pedalling more difficult while loosening it makes pedalling easier. On most bikes, the brake can be completely loosened, leaving no resistance to pedalling except the inertia of the flywheel; or it can be tightened to a point that the rider can no longer generate enough force to turn the flywheel. Usually, riders who can not tolerate the resistances called out by the instructor are encouraged to ride at a level at which they feel comfortable yet challenged.
2. by changing the cadence (the speed at which the pedals turn). Pedalling faster against high resistance expends more energy than pedalling slowly against low resistance.
3. by sitting or standing in various positions:
* forward; hands at the frontmost part of the handlebars
* middle; hands between the front and rear of the handlebars
* rear; hands at the rearmost part of the handlebars (the usual position when sitting)
* hovering; standing with all movement in the upper body and hips stopped and only the legs in motion
Each of these positions works the muscles in slightly different ways. Proper form for standing while pedalling requires the body to be more upright and the back of the legs touching or enveloping the point of the saddle, with the center of gravity directly over the crank.
A spin class is usually conducted to music. Riders may synchronize their pedalling to be in time with the rhythm of the music, thus providing an external stimulus to encourage a certain tempo. Often, the music chosen by the instructor is dance music or rock music set to a dance beat (i.e. 4/4 time), but not necessarily. This tends to help motivate participants to work harder than they might otherwise. While the music provides a tempo cue, the cadence does not need to be a multiple of the beat in order for the rider to feel in rhythm; the music therefore helps a rider maintain any constant cadence, not just a cadence that matches the beat.
It is recommended when riding in a spin class to bring plenty of water. Spinning is very energetic and causes a lot of sweating, and a person who is near dehydration can easily be dehydrated by the end of an hour of hard riding.
The flywheel resistance control is also used to brake the flywheel. When changing from fast pedaling to slow, the flywheel brake may be used to slow the flywheel rather than allowing the force of the angular momentum to be applied to ones knees and legs.