Your workout length and intensity should match your current fitness level and stamina. "If the workouts are so challenging and vigorous you dread them, you might give up," says Bauer. "It’s better to start off slow and gradually make your work-outs longer or more intense as your fitness level improves." There might be more time for working out in your schedule than you think. "You don’t have to commit to 30 continuous minutes," says Bauer. "Break it up into 10 minute chunks—10 minutes of walking in the morning, 10 minutes on your lunch break, and 10 minutes after dinner."