There are lots of different types of anabolic steroids , but most of them beefify similarly. When we work out, we create tiny micro-tears in muscle fibers. When the muscle regrows and heals, it grows back a little bit larger, and repeating that process over time is how we get hard and massive (that's the idea anyway). The male sex hormone testosterone facilitates that muscle growth. Anabolic steroids do the same thing but better and faster. They also speed the muscle-healing process by blocking the stress hormone cortisol, which breaks down muscle tissue. That can mean less down time for athletes who go into overtime.