Indoor cycling classes take place on stationary bikes and are led by energetic instructors with motivating music. Riders simulate flat roads, hills, and sprints by adjusting resistance and cadence. A typical 45-minute class provides an intense cardiovascular workout that burns 400 to 600 calories. Spin classes build leg endurance, improve heart health, and offer a fun, communal fitness experience. They are suitable for beginners because riders control their own resistance, and for advanced athletes who want a challenging interval session. Many gyms offer themed rides, power-based training, and virtual classes.