Pexels: Tima Miroshnichenko

Sometimes halfway is the best way. Most bodybuilding training advice prescribes full ranges of motion, and generally this is the best strategy. However, if done correctly, limiting your ROM can focus more tension on the targeted body part. We’re not speaking here about partial reps done after reaching failure with full reps, though those too can be very effective. Our focus instead is on sets that consist of only half reps or those that combine half reps and full reps. This kind of “half-stepping” can make sets harder and more effective. Let’s explore half reps, 21-curls, and other “halfway” combinations.


The reason to do half reps is to focus more on a specific part of an exercise’s range of motion. Sometimes this is done with compound exercises to increase your strength during a sticking point. For example, you may work on only the top halves of bench presses in order to get stronger lockouts—the area where many bench presses fail. You can do the same thing to turn bench presses into a triceps exercise, because triceps are the prime movers during lockouts (pectorals play a greater role during the bottom halves of reps). Because multiple muscles are stimulated during a compound lift, it’s crucial to select the right segment of such exercises to target. For example, rack deadlifts eliminate most lower body movement and thus focus more on the back and trapezius than full deadlifts.

half reps
Steve Kuclo finishes his back workout with rack deadlifts. / Instagram


You can also do half reps during isolation exercises. Select a lift with a long range of motion. Shrugs, for example, would be a poor choice because their ROM is short. The bottom halves and top halves of reps are virtually the same. Leg curls, leg extensions, barbell curls, triceps pushdowns, pec-deck flyes, and side laterals are all isolation exercises with long ranges of motion, and therefore can be worked effectively with half reps.

Typically, people focus on contractions with half reps. They may only bring the pads halfway back and then all the way together when pec-deck flying or do just the top halves of dumbbell side laterals. This is valid. But don’t sleep on stretches. New research shows the biceps are most stressed when maximally stretched during preacher curls. So, that would be during the lower halves.


Reps of varying lengths can be combined within a set. The best-known way of achieving this is via 21-curls for biceps, which consist of seven reps from the bottom to halfway, seven reps from halfway to the top, and seven full reps. Numerology aside, there’s nothing magical about either 21 or seven. You could accomplish the same with subsets of six (for 18 total reps) or eight (for 24 total reps) or similar amounts. Also, 21’s are not exclusive to biceps routines. They work with other long-range-of-motion isolation exercises. Triceps pushdowns, leg extensions, leg curls, and pec-deck flyes are among the best candidates for 21’s.

21 curls
Pushdowns can also be done 21-style. / Pexels: Carlos Mario

With either isolation or compound exercises, there are other effective ways of combining half reps and whole reps.

You can do half and whole: all the half reps followed immediately by all the whole reps. For example, do eight half-reps of leg extensions (focused only on the top half of the ROM) followed by eight full reps.

You can do one and a half reps: alternate a half rep with a whole rep. For example, you can do a half rep of bench presses (focused on either the top or the bottom half of the ROM) followed by a full rep. Go back and forth. This is a good way of focusing more on a specific area in the ROM of a compound exercise. Or you can do a half rep of an isolation exercise (such as the bottom halves or curls) alternated with full reps to increase intensity. Another variable for one and a half reps is speed: Alternate slow half reps with fast full reps throughout a set. This focuses more on the sticking points of compound exercises and further increases the intensity of isolation exercises.


The key to successfully using half reps is to make certain they apply more stress on the targeted area, not less. Frequently, weight-trainers limit their ranges of motion in order to hoist more metal. Invariably, anyone doing this focuses more on the easiest portion of reps (such as the shallow top of leg presses or the bouncy bottom of incline presses) and skips the hardest segment entirely. Utilize half reps to make your sets harder and more efficient, not easier and less effective.


? Select compound exercises that allow you to focus on specific muscles over a limited ROM, such as triceps during the lockouts of bench presses.

? Select isolation exercises that have a long ROM, such as biceps curls.

? Combining half reps with full reps in the same set allows you to better target muscles and boost intensity.

? 21’s can be done with many more exercises than curls, and they don’t have to total 21 reps.


? We’ve designed an arm routine of only half reps to illustrate what can be done. Generally, only one exercise per body part should feature half reps.

? For safety and to assure you hit the precise depth, use a power rack when doing half reps of deadlifts and a rack or Smith machine for chest presses.

? To better target half reps of compound exercises, do them after isolation exercises for that muscle. For example, do bench presses lockouts after pushdowns and triceps extensions, as in the routine below.

? Slow down your half reps. Make them last at least as long as your full reps.



Pushdown 21’s  — 4 sets x 21 reps

Overhead Triceps Extension 1+1/2’s  —  4 sets x 12-14 reps*

* Alternate a 6-7 bottom half reps with 6-7 full reps.

Bench Press Lockouts  — 4 sets x 10 reps


Barbell Curl 21’s  — 4 sets x 21 reps

Preacher Curl 1+1/2 Reps  —  4 sets x 12-14 reps*

* Alternate a 6-7 bottom half reps with 6-7 full reps.

Cable Curl Half Reps  — 4 sets x 12-15 reps