Here's what you need to know...
- Traditional 21s are a classic exercise that split the range of motion of a biceps curl into three mini-sets: bottom range, upper range, and full range. Seven reps of each range are performed per set.
- Reverse 21s function as a mechanical drop-set whereby the set gets "easier" as fatigue sets in.
- The reverse 21 method can be used with a number of exercises. Just start with full reps, then move to the harder partial-range reps, and finish with the easier partial-range reps.
Any lifter worth his salt has tried 21s with biceps curls and has felt the brutal pump that ensues. It's a classic hypertrophy training technique that works, and 21s can be used for other muscle groups as well. Here's the kicker: reverse 21s are even better.
What are Reverse 21s?
Let's use the example of a biceps curl. Traditional 21s look like this:
- Do 7 bottom-half partials where you start with the arms fully extended and curl halfway up until the forearms are parallel to the floor.
- Immediately follow that by doing 7 top-half partials where you start with the arms fully flexed and lower them halfway down until they're again parallel to the floor.
- Finish with 7 agonizing, full range of motion reps.
So if you consider bottom-half partials, top-half partials, and full reps to be three separate exercises, you're essentially going from the easiest exercise to the hardest exercise.
Reverse 21s invert that order. Start with the hardest part of the set and finish with the easiest part. For biceps curls, it would look like this:
- Start with 7 full reps.
- Now do 7 top-half partials.
- Finish with 7 bottom-half partials.
Put another way, reverse 21s function as a mechanical drop-set whereby the set gets easier as fatigue sets in. It's much easier to crank out some bottom-half partials at the end of a set when your biceps are already cooked than it is to do full reps.
You end up going through the same total range of motion over the course of the set, only you're able to use significantly more weight. For example, if you'd normally do traditional 21s with 75 pounds, you'd probably be able to do reverse 21s with around 95 pounds. More weight through the same total range of motion is the recipe for more muscle. Small tweak, big difference.
The reverse 21 method can be used with a number of body parts, but the specifics and order of execution will vary slightly between exercises because some are harder in the bottom range and others are harder in the top range.
Just remember that you want to start with full reps, move to the harder partial range, and finish with the easier partial range. Also, there's nothing magical about the number 21 or doing 7 reps per mini-set, so if you want to adjust the rep range, go right ahead.
Here are some of the best ways to employ reverse 21s for the major muscle groups.
Pick a weight that you could front squat for 15 reps and start with 7 full reps. Then do 7 bottom-half partials where you start from the bottom position and come halfway back up. Lastly, finish up with 7 half squats (you know, what most guys do for normal squats).
This is a great way to blast your legs with relatively lighter weights, which is helpful because many people struggle to hold heavy weights on front squats without dumping the bar. It also means you can fry your quads with less stress on the lower back.
While they're often too hard for most to do, glute-ham raises work well with this method. Begin with full reps and then do bottom-half partials starting with your torso parallel to the floor and coming up halfway. Then finish with top-half partials. Start with 2-3 reps in each range for a total of 6-9 reps per set and gradually build from there.
Machine leg curls – both seated and lying – are also perfect for reverse 21s.
The reverse 21 method works really well for chin-ups and can easily be modified to fit your current chin-up ability level. It's rare to find guys that can crank out 21 good chins, but if you can knock out 14 to 15, then you should be more than capable of doing reverse 21s. It's a great way to thrash your lats and upper back.
Start with full reps, then do top-half partials where you start with your upper arms parallel to the floor and pull yourself all the way up. Finish with bottom-range partials where you start with your arms fully extended and pull up until your upper arms are approximately parallel to the floor.
If 21 total reps is too ambitious at first, adjust accordingly. Even if you're doing 2-3 reps per mini-set, it's still a great way to hit your back. Lat pulldowns also work well, but in my experience rowing variations don't work as well. Stick to vertical pulling exercises.
Use either an incline bench or a flat bench and start with 7 full reps of dumbbell presses. Then do 7 bottom-half partials followed by 7 top-half partials where you consciously try to squeeze your chest at the top of every rep.
I've found that selecting the right weight is a bit of a crapshoot at first, so start conservative with a weight you can get for 16-17 reps and build from there.
Start with 7 full reps of dumbbell lateral raises. Then do 7 top-half partials where you only come part of the way down, and then finish with 7 bottom-half partials. To really give your shoulders a beatdown, try doing an isometric hold halfway up after you've completed the last 7 bottom-half partials.
Keep your arms straight or at least almost-straight. This will require using lighter weights, so ditch the ego. Nobody gives a shit how much you can lateral raise anyway.
Putting It To Use
There are several different ways in which you can incorporate reverse 21s into your workouts.
- Use them as finishers after completing your heavier work. For example, you might do 5x6 front squats working up to a heavy set of 6 reps, and then drop the weight down and do a set of reverse 21s before crawling back to the car. For shoulders, you could do heavy overhead presses and follow it up with 2-4 sets of lateral raise reverse 21s.
- Use them on "light" days. I typically recommend that people limit heavy barbell work to once a week for each major movement to limit overuse injuries and joint problems, so if you want to work a muscle more than once a week, the remaining work would come from lighter, joint-friendly stuff. For example, if you're working your chest twice a week, you could do heavy barbell bench press one day, and on another day do 2-4 sets of dumbbell press 21s as a way to get a training effect while giving your shoulders and elbows a break from the heavy weights.
- For chin-ups, reverse 21s are a chance for advanced chinners to get away from heavy weighted chins to give their elbows a holiday. For people that struggle with chin-ups, reverse 21s are a way to get extra work in by knocking out partials after you can't do full reps. For upper body exercises, shoot for 2-4 total sets, unless you're just doing one set as a burnout after heavier work. For front squats, 1-2 sets are more than enough if you're doing it right.