You’re a tough guy, eh? Or maybe a tough gal? Just how tough? Stack.com has created a list of 
In “10/10 Treadmill Fitness Test,” set both your elevation and speed to 10. If you are very fit, you should be able to run for two minutes. Don’t try this if you’re not already fit, and don’t do it alone because you could shoot off the treadmill! You want to destroy yourself, not destroy yourself.
And then there’s the grueling “100-Yard Power Wheel Challenge,” which the University of California at Berkeley found to be the most effective core-training exercise. It’s simple: “Assume a push-up position with your feet on a power wheel. Crawl for 100 yards,” according to stack.com. Don’t know what a power wheel is? Watch the video on stack.com.
If these don’t sound strenuous enough, there’s “60,000 Pounds in 60 Minutes Challenge,” “Iron Pirate Walk-Over,” “Inverted Ladder,” and more.
And after you try these gutty workouts, make sure to drink pr2, a great tasting, whole protein drink that’ll help you recover faster than ever before. You’ll be “destroying” yourself again before you know it!