Far superior to the lower quality, hard as a rock, black, high density smooth rollers on the market, the Planet Fitness muscle roller is a smart addition to your home gym equipment. The small spikes are made of medium density foam, they are dense enough to provide exceptional relief for overworked muscles, but pleasant enough for a beginner looking to get started with deep tissue massage. As you progress on your journey of physical fitness, rolling will first help you to loosen up and avoid injury from "overdoing" it, especially if you don't work out on a consistent schedule. As your fitness level increases, using your deep tissue massager will become part of your basic routine, flushing lactic acid from your muscle tissue. The compact projections are laid out in a geometric pattern for full coverage and proper spacing - pinning, stretching and lengthening the soft tissue for maximum effect.