Muscles worked
As in every curl, the biceps do the lifting, with the brachialis and brachioradialis helping. Here, leaning back puts your upper arms behind your body, and since the long head of the biceps attaches above the shoulder joint, the muscle is more stretched at the bottom than when you stand. The exercise is often said to favour the long head, although the biceps always work as a whole. The lower the backrest, the bigger the stretch and the lighter the dumbbells. Many people use roughly 45 to 60 degrees.
Common mistakes
- Using the dumbbells you stand with. Most people are clearly weaker in the stretched position, and heavy dumbbells make your shoulders try to help. Start a couple of steps lighter than your standing curl.
- Turning before your arms hang straight. The point of the exercise lies at the bottom, where the biceps are most stretched. Straighten your arms on every rep, but without bouncing.
- A backrest too low for your shoulders. If you feel a pull at the front of the shoulder at the bottom, the position is too deep for you, so raise the backrest a notch. If it hurts, not just feels hard, stop the exercise and have it looked at by a doctor or physiotherapist.
Variations and alternatives
- The dumbbell curl is the standing version, for when you want heavier dumbbells.
- The Bayesian curl also keeps your arm behind your body, but the cable gives resistance right at the bottom too.
- The spider curl puts your chest on the same bench and your arms in front of you, training the biceps from a less stretched position.
Sets and reps
Two or three sets of 8 to 12 reps make a good start for building muscle. Heavy low-rep sets suit it badly, as lowering into the stretch gets hard to control near your limit. The guide to sets and reps explains why different goals call for different rep counts.
Do a light set first so your shoulders and elbows can get used to the position; the guide to warming up has more. Then add reps from session to session and move to the next pair of dumbbells once every set reaches 12. That is progressive overload, even with light dumbbells.