This 12 minute workout is supposed to be tough, get your heart rate up, make you sweat, and make you wonder when 12 minutes is up. If it doesn't, you didn't do it right and should immediately do it again.
Set your timer for 12 rounds of 50 seconds of work followed by 10 seconds of rest. Be sure to wear shoes and be nice to your knees by landing softly. Do as many reps of each exercise as you can in the 50 seconds. Clear a little space, jog in place and shake out your arms to warm up for a bit, then GO!
1. Mountain climbers
2. Burpees
3. High knees
4. Push up, jump with feet together to right, Push up, jump with feet together to left
5. Jumping jacks
6. Squat jumps
7. Backwards lunge with front kick right
8. Backwards lunge with front kick left
9. Running man - 3 skis, then a knee, 3 skis other knee, arms reach and pull overhead
10. Hiesman - 3 quick shuffle steps to the right, freeze left high knee, 3 quick shuffle steps to the left, freeze right high knee

11. Prisoner Jacks - in squat position with hands behind head, jack in and out while staying low in squat
12. Do 10 high knees, 2 squat jumps, 1 tuck jump