Definition: Training technique that involves moving from one exercise to another, each exercise working a different muscle group until each muscle has been worked. It can include strength training stations, cardio stations or a mixture of the two. The purpose is to keep the heart rate elevated, although many experts feel that, with circuit training, you're actually getting the worst of both worlds since you're splitting your energies between cardio and strength. It can be a good workout but, like any training method, should be changed every 4-6 weeks to avoid boredom and plateaus.