The preacher curl puts your elbows on an angled pad, so your biceps work with no cheating from the shoulders.
1Starting positionStart2End positionFinish
Setup
Set the seat so your armpits rest on the top edge of the pad. Take an EZ-bar or barbell with an underhand grip. Upper arms and elbows on the pad, arms nearly straight.
Execution
Brace your chest and upper arms against a preacher bench, hold the EZ-bar with your arms straight — starting position.
Inhale and lower the bar until your biceps are fully stretched.
Exhale and curl it back up to your shoulders, squeezing your biceps.
Common mistakes
Dropping the weight at the bottom — that's how biceps get hurt; lower slowly and don't snap to full extension.
Lifting your elbows off the pad — they stay down the whole set.
Pad under your belly instead of your armpits — raise or lower the seat.
Rolling your shoulders forward to finish — finish with your arms only.
Not sure about your form? Send me a video of a set — I'll take a look and tell you what to fix first.