When circuit training, exercises are performed in quick succession with very little rest between. Transition quickly between upper, lower and total body movements performed for 8-20 repetitions (or 20-60 seconds). Circuits can be repeated a couple or few times through. The obvious benefit to this system or method of resistance training is time efficiency but the added bonus is aerobic conditioning! Circuit training workouts can cause modest improvements in aerobic or cardio conditioning on account of how hard the heart works to pump blood to all your moving parts – and with limited recovery time! If your idea of feel good cardio isn’t lacing on your trainers, hitting a treadmill, elliptical, or stair climber, try doing your strength training exercises faster – feel your heart rate rise and your breathing quicken. That’s cardio!