Mashing is pedaling high gear but slowly—pushing large gears slowly. It is usually done when climbing steep hills or battling gusty winds, where there is much needed muscular effort with each pedal.
Mashing develops leg strength and power but is harder on the joints and heart. Endurance riders may mash periodically for short intervals, such as climbing a hill or flying out of a turn, but tend to pedal at higher cadences on extended climbing to conserve energy. Combining mashing and spinning workouts into training makes both the muscles and the rider better able to handle various surfaces and techniques.