Which part of the bicep curl builds more muscle?

Different ways of performing biceps curls lead to small but detectable differences in how much muscle grows in specific areas and how much strength improves for that movement.

In untrained young women, lifting weights through the first half of the elbow movement for eight weeks leads to greater gains in overall strength than lifting through the second half, even if the second half involves heavier weights.

In untrained young women, performing bicep exercises through a shorter range of motion (from fully extended to halfway bent) leads to more muscle growth near the elbow than using a longer range (from halfway bent to fully bent), but both approaches result in similar muscle growth in the middle of the bicep.

In untrained young women, performing bicep exercises using only the first half of the movement range for eight weeks leads to more muscle growth in the lower part of the biceps and greater strength gains than using only the second half of the range.

In untrained young women, training the biceps through the fully bent position of the elbow for eight weeks does not lead to more muscle growth than training through the partially bent position, when measured by muscle size at specific points along the upper arm.