How tough are you? After a few rounds of this punishing upper-body circuit, we pretty much guarantee you'll know the answer.

Complete at least four—and as many as six, if you're a total monster—back-to-back rounds of eccentric pullups, mountain climbers, eccentric chinups, and then one more set of muscle-burning mountain climbers for a complete upper-body burn. You won't get a prize for getting through this workout in one piece, but you'll have gotten one step closer to building serious strength and endurance.

Directions

You'll do this workout as a circuit, meaning you'll complete each exercise consecutively without rest. Once you've finished all exercises, rest for 60 to 90 seconds. Repeat the entire circuit for four to six rounds.

Depending upon your ability, you may shorten or lengthen the rest periods between circuits. You may also complete more or fewer rounds.

For more upper-body work:

Check out our favorite six total-body supersets that'll blow up your muscles, our 10 upper-body moves that build your core, and our 25 strength-training exercises for the best upper-body workout of all time.

For a complete archive of our daily quick-hit routines, go to mensfitness.com/todaysworkout.