Dumbbell 21s
Dumbbell 21s combine seven bottom-half curls, seven top-half curls and seven full curls to train the elbow flexors in one continuous sequence.
BICEPS · PULL
How it is executed
- Stand with dumbbells in each hand, palms up.
- Perform 7 reps from the bottom to halfway, then 7 from halfway to the top, and finally 7 full-range curls.
- Control each phase, keeping your elbows fixed to your sides.
Common mistakes
- Changing the midpoint each rep: use a reference.
- Swinging at the end: reduce load.
- Skipping full reps: keep all three blocks.
Frequently asked questions
- Is it 21 sets?
- No. One sequence contains 21 reps split into three groups of seven. The number of sequences depends on your program.
- Do you use your regular curl weight?
- You usually need less load to finish all three parts without swinging. Do not sacrifice the final full-range block to start heavy.
- Do they replace all full curls?
- Not necessarily. They organize reps differently; full-range work remains useful and easier to compare between sessions.
Sources and editorial approach
The explanation, variations and FAQs are Kaizer’s editorial synthesis. ACSM’s 2026 guidance provides general context on progression and resistance training in healthy adults; it does not independently validate the technique of each variation.
No individual professional review is recorded for this page.
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Glossary and calculators
Warm-up setsWarm-up sets are the sets before the real work, with rising load and falling reps, that prepare the pattern and the nervous system for the target load.RIR (reps in reserve)RIR is how many repetitions someone could still have completed at the end of a set before reaching technical failure.Price per sessionHow much to charge per session
