21s

Stand upright and grab the barbel at shoulder width. Keep your elbows tucked into your body and your palms should be facing towards your elbows. This is your starting position.

While keeping the upper arm stationary, exhale and slowly begin to bring the bar to your midriff.

Once at this point, lower the barbell back to its starting position. Repeat this 7 times.

After you have performed that motion 7 times, now bring the barbell up at around shoulder level. This is your second starting position.

Now begin to lower the barbell down to your midriff. Your upper arms should remain stationary while performing this motion.

Once the barbell has reached your midriff, begin to bring the barbell back to its second starting position. Repeat this 7 more times.

Once you have completed that step, hold the barbell in a standard curling position and begin to complete 7 standard barbell curls.

You have just performed 21 reps.