"Using a pair of lighter dumbbells is no joke," says Todd Durkin C.S.C.S., author of The IMPACT! Body Plan. "The lighter load allows you to perform exercises with more power and speed, activating all your muscles fibers."
Grab a pair of 20- to 25-pound dumbbells, and perform the challenge as a "ladder." Begin with one rep of each exercise -- the hammer curl, straight-leg deadlift, and overhead press -- moving from one to the next without rest. Next, do 2 reps of each move, and then three, and so on until you've completed 10 reps of each exercise. By the end, you'll have completed 165 fast-paced reps with little rest.
"If you go all-out from start to finish, you'll be surprised how heavy those dumbbells will feel by the end of this challenge," says Durkin, who completed this maniacal muscle burner in just 3 minutes and 27 seconds. (Boost your gains by downsizing your workout with The One Dumbbell Workout.)
Can you beat his time? Try it and let us know in the comments below.
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