The 21s Barbell Curl is a high-intensity bicep finisher that combines three ranges of motion in one set. Using a barbell, perform 7 reps from the bottom to halfway, 7 reps from halfway to the top, and 7 full-range reps. This totals 21 reps, keeping constant tension on the biceps brachii and pumping the muscle with blood. Gymcheq emphasizes strict form—no swinging, no rushing—just controlled curls to maximize growth and endurance.