The best biceps exercise, according to science

Ask someone to flex, and chances are they’ll strike the classic double-biceps pose. Ask them what the best biceps exercise is, and you’ll probably hear “dumbbell curl.”

That's not a bad guess, especially as it's an incredibly simple, yet effective bicep builder. But, according to science, there’s a clear winner – and it's not that. The winner is...drumroll please...the concentration curl.

The science of bigger biceps

The human body is an amazing bit of kit, so when it comes to strength training, it makes sense to turn to science for the best results. That’s exactly what a group of researchers did when they set out to find the most effective exercise for targeting the biceps brachii—the front-of-arm muscle that gives your flex its shape.

In a small study, 16 healthy men and women were asked to perform a one-rep max (1RM) for eight popular biceps exercises, including the barbell curl, preacher curl, and hammer curl. Using electromyography (EMG) to measure muscle activation, researchers tracked which movement sparked the most activity in the biceps.

The result? The concentration curl came out on top—delivering the highest level of biceps engagement of all the exercises tested.

Other exercises they compared included:

• Cable curl
• Barbell curl
• Chin-up
• EZ bar curl (wide and narrow grip)
• Incline curl
• Preacher curl

To measure how hard the biceps were working, researchers at the University of Wisconsin-La Crosse attached EMG electrodes directly to the biceps brachii. The data showed that the concentration curl significantly outperformed the rest, triggering the most muscle activation. The cable curl came in second, and chin-ups took third place.

So why did the concentration curl come out on top – and how do you do it?

Meet the concentration curl

The beauty of the concentration curl lies in its simplicity and effectiveness. “It enforces strict form and allows the muscle to stretch fully before contracting, leading to greater peak development when repaired and flexed,” says Jack Claxton, Level 3 Personal Trainer and Personal Training Ambassador at David Lloyd.

With your upper arm braced firmly against your inner thigh, there’s no room for swinging or momentum – meaning your biceps are doing all the work. “This isolation maximizes the contraction,” Claxton explains.

Even better? The study also found that the concentration curl minimizes involvement from the anterior deltoid (the front part of your shoulder), ensuring your biceps aren’t missing out on any of the muscle-building magic and your shoulders aren’t stealing the show.

How to perform the concentration curl

• Sit on a flat bench, holding a dumbbell in one hand with your elbow resting on the inside of your thigh.
• Keep your upper body still and your core engaged—no swinging!
• Slowly curl the dumbbell toward your shoulder, squeezing your bicep at the top.
• Lower the dumbbell with control and repeat.

Claxton recommends starting with 3 sets of 10 reps, focusing more on form and mind-muscle connection than on heavy weights. “It’s not about how heavy you go – it’s about how well you feel the muscle working,” he says.

If you haven't already, then it looks like science has spoken, it’s officially time to add the concentration curl to your arm-day routine.