Movement of the month: the barbell curl

Carrying shopping bags, lifting a child, picking up a box with your palms up: the curl trains the muscle that bends the elbow. It is the simplest lift in the series, and the only one that trains a single joint.

What it trains

• →The biceps and the muscles of the forearm, which bend the elbow and hold the grip.
• →The trunk, a little, which keeps the body still while the arms move.

Where it fits

The five earlier lifts in this series are compound movements, which work several large muscle groups at once. That is where most of the evidence on keeping lean mass during weight loss sits. The curl is an isolation exercise: it trains one muscle group, and it is usually treated as an extra after the main lifts, not a replacement for them. Exercise guidelines, including the American College of Sports Medicine's position stand, include single-joint exercises alongside compound ones in a balanced routine. It earns a place because grip and arm strength matter for everyday carrying, and because it is easy to learn.

Where to start

• →With dumbbells or an EZ bar if a straight bar bothers your wrists.
• →With your elbows pinned to your sides. They stay still; only the forearms move.
• →Without the swing. If you have to lean back or use your hips to get the bar up, the weight is too heavy.
• →With a slow lowering. Taking the bar back down under control is half the exercise.

Safety and sense

Stop if you feel sharp pain at the elbow or wrist. Mild soreness in the biceps a day or two later is normal. If you have an elbow or wrist injury, ask a physiotherapist about grip and bar choice.

What this feature isn't

It isn't a plan. We don't give loads, sets or repetitions. That completes the six lifts in this series; the full set is on the Movement page.