AMRAP (as many rounds as possible).
Doing high intensity circuits such as these have similar endurance benefits as running or biking for an hour or more a day. Not only that, but it works your entire body and not just focuses on one area such as your legs, arms or core. You'll improve strength and conditioning and start to shape a lean and mean physique in shorter time. Here are some other benefits:
Destroys fat and can build lean muscle.
Great self measurement of progress. See how many rounds you complete each time you try it.
Amazing for your fitness levels.
Improves strength, flexibility and conditioning.
Can be done almost anywhere, requiring little to no equipment.
Here's a list of some amazing AMRAP workouts to add to your workout queue...