Back Squat
  4-4-4-4-4

With a Running Clock - As Many Reps As Possible
0-3:00 Minutes
  3 Rounds
    3 Pull-ups + 6 Push-ups + 9 Air Squats
3:00-6:00 Minutes
 3 Rounds
   4 Pull-ups + 8 Push-ups + 12 Air Squats
6:00-9:00 Minutes
 3 Rounds
  5 Pull-ups + 10 Push-ups + 15 Air Squats
Etc....