These puke inducing, balls-to-the-wall workouts will pretty much make you pass out. Based on the same principles as HIIT, except 911’s will incorporate 2 to 5 multi-joint exercises with no rest between. Use these as a break from weight training for a couple weeks and you will see some massive gains when you return to the gym.

Try to do 2 to 6 circuits 3 to 4 days a week for two weeks and you will notice an increase in metabolism and overall endurance as well as increased lung capacity. Some of the 911’s require a partner, which helps with intensity and accountability as well as having someone to call 911 when your lungs collapse. So step away from the squat rack Hans, your quads will not atrophy in two weeks, and try some of these.