Why it works: This variation on the biceps curl targets (and torches) every part of the muscle area, and is one of celebrity fitness trainer Todd Durkin's favorites.
How to do it: Pick up a barbell and do seven bottom-half biceps curls — in other words, don’t curl the bar higher than your elbow. After the seventh rep, pull the bar all the way up to your shoulders and do seven more curls, but this time lower the bar until to the height of your elbow. Finally, finish the set off with seven full-sized curls. Repeat for three total sets of 21 reps.