Lunge Pulses

How do you make lunges harder?  Do a static lunge and pulse it!

Start in a lunge position (one foot forward with knee behind the toes and back heel is up), while pushing through your front heel, sink down as low as you can (which means the back knee is close to the floor) and go up and down (but not all the way) - it's just a small movement up and down.  Repeat for all reps and then do the other side!