Split Squats (add weight if you can, barbell will work well)
Back Extensions
KB or DB Chest Press
One Handed KB Swings - Alternate Hands
-or- Two Handed DB Swings (if you don't have KB)

Repetition Count:
20-15-10-5
15-10-5-20
10-5-20-15
5-20-15-10

Complete 4 rounds

Example of first round:
20 Split Squats
15 Back Extensions
10 KB Chest Press
5 Alternating KB Swings