The workout everyone has been talking about! The Insanity 20 min workout. The plan: Do each sizzler for one minute without stopping between exercises. After you've completed one round, rest for 60 seconds, then go again. Perform the circuit three times (20 minutes and done!), two days in a row. Take a rest day, and repeat. To turn up the burn, put as much oomph as you can into every movement.