Hardcore disciples of “functional training” love to bash isolation exercises for their lack of real-world carry-over, and the classic concentration curl is as isolating as it gets, what with upper-arm movement restricted by the inside of the leg. But in the real world, both guys and girls like having bigger pipes, and according to a study published in 2014 by the American Council on Exercise (acefitness.org), this would make the aforementioned exercise as functional as any. ACE commissioned a team of researchers to identify the “best” biceps exercise, and guess which one won? Yep, the concentration curl. The researchers compared six different variations of biceps curl (cable, barbell, concentration, EZ-bar, incline bench and preacher), plus chin-ups, and found that concentrations elicited significantly greater biceps muscle activation than all the others. Sounds to us like a great carry-over to the real world, in which a T-shirt that fits snug on the bi’s feels pretty damn good. So finish off your next arm workout with three to four sets of 10 to 12 reps of concentration curls.