One of the best things about the True Muscle Trainer is that the workouts don't take very long. If you do it right, you can be in and out of the gym in an hour or so. That kind of training style is perfect for people who have work, a family, friends, and other things that make up a life.
So, don't stand around and talk or play on your phone. Rest as much as you need as little as possible. Keep your heart rate up and the sweat pouring. Walk out of the gym confident you did exactly what you needed to in order to improve.