How to do the 21s bicep curl

Step by step

1. Grab a straight or curved bar evenly and stand tall. Bring your shoulders back, squeeze your glutes, and take a breath.
2. Curl the weight halfway (to the point where your wrists align with your elbows) for seven repetitions.
3. Immediately start curling the bar from the halfway point to the top (where your wrists are a couple of inches higher than your elbows) for another seven repetitions.
4. Finish by doing seven complete repetitions from full arm extension to the top position, breathing steadily as you do.

Muscles worked

Sets and reps

Pick the row that matches your goal. Add weight or reps once every set feels controlled, and log each set so you can see the trend.

Programs that use the 21s bicep curl

• 6-Week Bigger Arms2 × 21

Track your progress

Repto shows what you lifted on your last session for every set, suggests your next weight, and starts the rest timer when you tick the set. Your estimated 1-rep max and volume for each exercise are charted over time.