Spinning is a form of indoor cycling exercise that involves using a special stationary exercise bicycle with a weighted flywheel in a classroom setting. It is a type of group indoor cycling workout, usually done in a large studio, and is designed to focus on endurance, strength, intervals, high intensity, and recovery. The term "spinning" is actually a registered trademark, referring to the unique fitness products and programs offered by Mad Dogg Athletics, Inc.
Indoor cycling, on the other hand, is a more general term that refers to riding a stationary bike on an indoor trainer. It most often refers to indoor bike training in which you ride an outdoor bike attached to one of the best turbo trainers.
Spinning classes generally use specialized stationary bicycles with features such as a mechanical device to modify the difficulty of pedaling, specially shaped handlebars, and multiple adjustment points to fit the bicycle to a range of riders. Many have a weighted flywheel, which simulates the effects of inertia and momentum when riding a real bicycle.
Spinning is a total body, low impact, high-intensity cardiovascular workout that can improve cardiovascular health by increasing heart rate and blood flow. It is also a time-efficient way to work out.