Circuit 3, Exercise 2: Plyo Lunge Stand with your feet together and your knees soft. Jump and come into a lunge with your left leg forward. Push off with both feet, jumping them together, then hopping into a lunge with your right leg in front. Jump your feet back together to complete one rep. Repeat for 40 seconds, then take 20 seconds of rest. If you find plyo lunges hard on your knees, do alternating back lunges instead. Image Source: POPSUGAR Photography / Maria del Rio