So if you are ever pressed at the gym for time (which only happens...ALWAYS), try this one out after you do an upper body workout. You will be sore the next day!!
1-35 Standing Squats (just put your hands behind your head and dip your butt straight down, be careful that your knees don't extend out past your toes.)
2-35 Lunge Jumps (Go into lunge position, then explode up while switching legs. Each leg alternating counts as one rep)
3-35 Standing lunges (with hands behind head)
4-35 Jump squats.
Try to do these with as little rest in-between as possible. Should be about 5min long...and your legs will be jelly! If they are not, then do it twice!!