Do you want to maximize your size and definition, but don't have the luxury to spend hours training? Use any of these three powerful 20-minute circuit-training workouts when time is of the essence.

Oftentimes, the hours in our lives just don't add up the way we'd like. Figure an hour to get ready in the morning, about 10 at work, a 60-minute commute each way, an hour for dinner, two to watch the game, three hours of quality time with the family at night '