what does bicep curls improve
If the outer head of your biceps is lagging you should do curls with your arms raised about 30 to 45 degrees forward. This is where the preacher curl comes in â a specifically formulated bench to assist you in keeping this specific angle and ultimately helping you improve the outer head of the biceps.he Biceps Curl. When you do traditional standing biceps curls, your biceps you naturally reproduce all of these movements. To work both heads equally you need to keep your forearms externally rotated, and keep your arms by your side (perpendicular to the floor) while bending at the elbow.