Switching up your shoulder position during bicep curls makes your muscles fire more, even if you're lifting the same total weight.

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Evidence from Studies

Supporting (1)

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The Effects of Varying Glenohumeral Joint Angle on Acute Volume Load, Muscle Activation, Swelling, and Echo-Intensity on the Biceps Brachii in Resistance-Trained Individuals

Randomized Controlled Trial

Human

2019 Sep 4

When people did bicep curls with their arms in different shoulder positions during the workout, their biceps worked harder overall than when they kept the same position the whole time—even though they lifted the same total weight.

Contradicting (0)

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No contradicting evidence found

Source Study

The Effects of Varying Glenohumeral Joint Angle on Acute Volume Load, Muscle Activation, Swelling, and Echo-Intensity on the Biceps Brachii in Resistance-Trained Individuals

Score: 51

DOI: 10.3390/sports7090204

Similar Assertions

Changing the angle of your shoulder while doing bicep curls makes your biceps work harder during the workout, even if you're lifting the same total weight.

86%

Even when you change your shoulder position during bicep curls, you still lift the same total amount of weight — your total workout effort doesn’t go up or down.

83%

Just because changing your shoulder angle makes your biceps work harder during one workout doesn’t mean it will make your muscles bigger over time — this study didn’t test that.

83%

Whether you change your shoulder angle or not during bicep curls, your muscles recover at the same speed over the next three days.

79%

When you train one arm, the other arm’s muscles start firing more easily and more intensely during contractions—even without being exercised—making it stronger through better nerve signals, not bigger muscles.

73%