The bicep anatomy responds excellently to muscle isolation because, in comparison with other body parts, the biceps are very small. So by ensuring that the target muscles do the majority of the lifting, you can improve the size and appearance of your arms.
The sissy curl, also called the sissy bar preacher curl, is a similar exercise to seated preacher curls in terms of biomechanics. The difference is that you perform sissy curls standing up and effectively use your core muscles as a preacher pad, which is to say that you brace your arms against your abs as you lift the weight.
Sissy curl exercise details
- Main Muscles: Biceps brachii
- Secondary Muscles: Brachioradialis, brachialis, forearm flexors
- Exercise Type: Strength
- Exercise Mechanics: Isolation
- Difficulty Level: Beginner
- Equipment Needed: EZ bar, weights
How to do sissy bar preacher curls
- Load an appropriate amount of weight onto an EZ bar or a barbell.
- Grab the bar just inside shoulder-width.
- Lift the bar in front of your body.
- Brace your upper arms and elbows against your abs.
- Curl the weight toward your shoulders and squeeze your biceps forcefully.
- Lower the weight under control until your elbows reach full extension.
- Repeat for 3-5 sets of 8-15 reps.
Sissy curl training tips
There are different types of sissy curls, but for the variation that I recommended above, these are the training tips that will help you to get the most from this exercise.
Use a full range of motion
It can be tempting to perform partial reps during sissy curls in order to keep the tension on your biceps. And while this reasoning does have some merit—half reps often result in a better muscle pump—it's not like locking out your elbows completely removes the tension from your biceps. 
Doing full repetitions ensures that the target muscles receive a good stretch as well as a strong contraction. It also helps to recruit a wider variety of muscle fibers because by performing complete reps, you're not just working one part of the biceps; you're training the entire muscle.
Try different equipment
The sissy curl is a flexible exercise in the sense that you can perform it with a variety of different equipment. EZ bars are the most obvious choice because they put your wrists in a comfortable position while simultaneously allowing you to test your strength by overloading your biceps with heavy weights.
Dumbbells, on the other hand, are highly effective for isolating your biceps and preventing muscular imbalances from occurring or worsening. The drawback is that this isolation comes at the expense of less overload because you can't lift as much weight with dumbbells as you can with barbells.
Since sissy curls isolate your biceps better than many other exercises, using a straight bar is also a good option. This is so because straight bars have you curl with your palms facing up, which is to say with them fully supinated. As such, your biceps receive a maximal contraction on each and every rep that ensures they're getting put under the most amount of tension possible.
Brace your arms against your abs
As mentioned, there are multiple ways to do sissy curls. For example, you can lean back as you curl to change the strength curve of the exercise, i.e., make it harder at the bottom of the rep like in a preacher curl. 
However, my favorite version of the sissy curl is more straightforward.
You perform a regular standing curl, but you do so while bracing your upper arms and elbows against your abs or ribcage. You'll need to use a relatively narrow grip to make this work, but the end result is that you get better bicep isolation because by bracing your arm against your abs, you're essentially using your core muscles as a preacher pad.
This makes the exercise especially effective for maintaining the proper form because as long as you keep your arms glued to your abs, you can't swing the weight up with your shoulders.
Sissy curl alternatives
The sissy curl is an excellent exercise because not everyone has access to a preacher bench. But at the same time, the movement isn't for everyone. So if you want to see some other bicep drills that really isolate the target muscles, be sure to check out these alternative exercises.
The preacher Zottman curl is a slightly unusual but nonetheless effective exercise. As you curl the weight up with supinated palms, the Zottman curl then has you lower the dumbbell with pronated palms, i.e., with an overhand grip, to shift the tension onto your brachioradialis. So in this sense, the exercise is a great overall mass builder for the arms, not just for the biceps.
If, however, you want to maximally isolate your biceps, then you can also use the Hammer Strength preacher curl machine (or any similar piece of equipment). This kind of apparatus enables you to easily keep the tension on your biceps because you don't have to stabilize the weight. As such, you can focus all of your attention on stretching and squeezing the target muscles to elicit maximum growth.
Conclusion: Should you do the sissy curl?
If you want to turn regular bicep curls into a better isolation exercise, then sissy curls (or sissy bar preacher curls) are an excellent choice because they make it very difficult to cheat the weight up. The trick—if you can call it that—is to always use a full range of motion so that your biceps get a good stretch as well as a strong contraction.
It's recommended to stick to sets of 8-12 reps for the most part so that you get plenty of time under tension without the extreme fatigue that can arise from performing high reps on all your sets.
- Tumminello, N. (2019, August 18). Midrange Partials for the Best Pump of Your Life. T NATION. https://www.t-nation.com/training/midrange-partials-for-the-best-pump-of-your-life/
- Oliveira, L. F., Matta, T. T., Alves, D. S., Garcia, M. A. C., & Vieira, T. M. M. (2009). Effect of the shoulder position on the biceps brachii emg in different dumbbell curls. Journal of Sports Science and Medicine, 8(1), 24–29. https://pubmed.ncbi.nlm.nih.gov/24150552/