If bigger biceps are a goal you’re after, traditional barbell curls may not necessarily be the best bang for your buck exercise. While a go-to staple in most arm workouts, traditional curls fail to provide much resistance at the bottom of the movement when the elbows are extended, and elbow flexors are in a lengthened position. And to get the most out of your bicep-building efforts, you also must program exercises that challenge the muscles at longer lengths, according to Menno Henselmans, a personal trainer and exercise scientist.

One 12-week study, published in the Journal of Sports Sciences , compared preacher curls and incline dumbbell curls . Participants trained one arm with preacher curls and the other with incline curls, and MRI scans revealed that preacher curls led to greater growth in the brachialis and brachioradialis. Comparatively, incline curls produced greater gains in the biceps brachii.…