Filthy Fifty For time: 50 Box jump, 24″ 50 Jumping pull-ups 50 Kettlebell swings (35, 25) 50 Walking Lunge steps 50 Knees to elbows 50 Push press (45, 35) 50 Back extensions 50 Wall ball shots (20, 14) 50 Burpees 50 Double unders