Spinning refers to riding a bike very fast and easily as well as an indoor cycling exercise typically performed in a group under music and varying levels of intensity.
Indoor spinning replicates road cycling in that you have hills, sprints, and flats that provide a vigorous but gentle workout. Endurance athletes use spinning for cross-training or recuperation days because it exercises the heart without risking injury. Spinning also allows cyclists to remain in shape when the weather turns bad or when it’s off-season.