Exercise guide
Barbell 21s
Barbell 21s are a biceps curl variation divided into three sections. You perform seven lower-half curls, seven upper-half curls, and seven full-range curls without setting the bar down. The format extends the set by challenging different portions of the curl range.
Training context
Using Barbell 21s in a workout
Barbell 21s are usually used as higher-repetition arm work rather than a heavy primary exercise. They can fit near the end of a pulling or upper-body session when the goal is to add focused biceps volume.
The sequence is already demanding, so choose a lighter bar than you would use for normal curls. Completing all 21 repetitions is less important than keeping the intended ranges clear and controlled.
Technique overview
Keep each section distinct
Stand tall with an underhand grip and keep your elbows near your sides. Perform seven controlled repetitions from full extension to halfway, followed by seven from halfway to the top. Finish with seven full curls. Avoid turning the partial repetitions into tiny pulses or using body swing as fatigue builds.
Treat this as an overview and use a range, pace, and setup you can control.