I learned the leg circuit at MTSU's speed school....it's a work out without weight but it's strength and endurance training all in four excerises on is a squat with the hands on the back of the head no weigts do that 20 times then alternating lunges 20 times then a step up exercise like on the end of a chair or something just jumping and alternating feet on the edge and then a squat jump just parellel squat with a jump when you come up the leg curcuit requires no weight what so ever you are just using your body weight hope I could be of some help holla