Partial reps are one of the best training methods for building size and strength. In my experience partial reps are especially effective for building bigger, stronger biceps. If you want to build big, strong arms then this article is for you!
- Part 1: 1.25 Reps
- Part 2: Post-Failure Partial Reps
- Part 3: Isometronics
In this comprehensive guide I will show you how to use partial reps to build big, strong biceps.
Partial reps are an advanced training method where you lift the weight through a partial range of motion. Partial reps are so effective because they allow you to use very heavy weights to overload specific points in the strength curve.
For example you can use partial reps to overload your muscles in the bottom position of an exercise when they are stretched or the top position of an exercise when they are contracted.
One of the most popular ways to train the biceps with partial reps is called “twenty-one’s.” The basic idea is to perform 7 partial reps in the bottom half of a bicep curl, 7 reps in the top half of a bicep curl and 7 full range of motion reps. Here is IFBB pro Phil Heath perfect video demonstration:
Twenty-one’s are probably the most popular way to use partial reps to overload your biceps. However, in my experience 1.25 reps, post-failure partial reps and isometronics are all even more effective for building big, strong biceps. If you start using these techniques in your bicep workouts then your arms will explode in size and strength!
Note: if you have trouble reading the training routines in this article then check out this guide on how to read a training program. Now let’s get down to business…
Part 1: 1.25 Reps
One-and-a-quarter-reps are a fantastic hypertrophy training technique that you can use for nearly every body part. You are going to perform a quarter rep in either the stretched or shortened position of the strength curve, followed by a full range of motion rep.
Both the quarter rep and the full range of motion rep together count as “1 rep.”
For example here is a set of 1.25 rep tricep extensions emphasizing the stretched position of the strength curve:
This is a fantastic technique for increasing the time under tension when the muscle is fully stretched. As you may already know, placing the working muscle in a loaded stretch is a very powerful way to stimulate size and strength gains in a muscle.
Of course 1.25 reps can also be performed to overload the shortened position of the strength curve. Here is a perfect demonstration of this method on chin ups:
This is an effective way to increase the time under tension in the shortened position of the strength curve. This can be a very effective tool for training the biceps as the biceps are contracting the hardest in the shortened position of various exercises.
It is very important to use the correct repetition ranges when using 1.25 reps.
On the on hand 1.25 reps should be reserved for hypertrophy phases where you are trying to build maximum muscle. Normally reps in the 6-20 range work awesome for this purpose.
However, you have to take into account that when you use 1.25 reps each of your reps takes longer to complete than normal. After all, each “rep” consists of one partial rep and one full range of motion rep.
For this reason I recommend you keep all of your 1.25 rep sets in the 6-12 rep range. Here is a sample bicep routine that you may want to try. It utilizes partial reps in the stretched position to maximally overload the biceps.
Check it out:
1.25 Reps Biceps Routine
- A1: Seated DB hammer curls, 4 x 6-8, 2/0/X/0, 180 seconds rest
- B1: 45 degree incline DB curl (supinated grip), 4 x 8-10**, 3/0/X/0, 10 seconds rest
- B2: Preacher ez-bar curl (narrow / supinated grip), 4 x 8-10**, 3/0/X/0, 120 seconds rest
Perform 1.25 reps in the stretched position on every rep.
One of the reasons that this routine works so well is the exercise selection. Preacher curls and incline dumbbell curls place the biceps under a larger stretch in the bottom position than any other exercises.
By using 1.25 reps in the stretched position of these exercises you further overload your biceps in the bottom position of these exercises. You can expect some deep delayed onset muscle soreness from this routine!
1.25 Reps Arm Routine
- A1: Machine bilateral preacher curl (supinated grip), 3 x 10-12**, 2/0/X/0, 75 seconds rest
- A2: Close grip bench press, 3 x 10-12, 2/0/X/0, 75 seconds rest
- B1: 60 degree incline cable curl (supinated grip), 3 x 10-12**, 2/0/X/0, 120 seconds rest
- B2: Standing ez-bar french press, 3 x 10-12, 2/0/X/0, 120 seconds rest
**Perform 1.25 reps in the shortened position on every rep.
This is a great workout to use if you have lagging biceps and you struggle to “feel” your biceps working during your sets. The 1.25 reps in the shortened position teach you to maximally contract your biceps on every rep.
Just give this arm routine a shot for 2-4 weeks if you don’t believe me! I promise you that your “mind-muscle connection” will improve dramatically.
1.25 reps are hands-down one of the most effective partial rep training methods that you can use to add muscular size to your biceps.
Of course they are not the only effective method. In my opinion the method covered in part 2 of this article is even more effective…
Part 2: Post-Failure Partial Reps
This is by far one of the most extreme ways to implement partial reps into your routine.
The idea is simple: you are going to train to technical muscular failure on any biceps exercise. After you reach failure you are then going to bust out 4-6 partial reps in the bottom position of the exercise.
These partial reps are a very short range of motion reps. The weight may only move a few inches before you have to lower it back down to the starting position.
These post-failure partial reps are absolutely brutal but they are simply fantastic for stimulating hypertrophy in the biceps. In fact the first-ever Mr. Olympia winner Larry Scott was a big advocate of partial reps.
Larry built his world-famous 20-inch arms in the 1960s using partial reps in the bottom position of preacher curls. He would actually perform a tri-set of three different types of preacher curls: dumbbell preacher curls, supinated grip ez-bar preacher curls, and pronated grip ez-bar preacher curls.
Actually this is a uni-angular tri-set, one of the most effective hypertrophy training methods.
Check it out:
Larry Scott Arm Workout
- A1: Bilateral dumbbell preacher curl (supinated grip), 3 x 6**, 2/0/X/0, 10 seconds rest
- A2: Preacher ez-bar curl (wide / supinated grip), 3 x 6**, 2/0/X/0, 10 seconds rest
- A3: Preacher ez-bar curl (wide / pronated grip), 3 x 6**, 2/0/X/0, 180 seconds rest
**Perform 4-6 partial reps in the stretched position after reaching failure.
The only thing not shown in this video is the partial reps that are performed in the bottom position of each exercise after reaching muscular failure. Give this routine a short for 2-4 weeks and I am sure you will agree that it is one of the very best ways to build bigger arms!
Here is another biceps hypertrophy routine featuring post-failure partial reps.
This routine is particularly brutal as it utilizes a post-exhaustion superset. In other words you are going to perform a superset consisting of a compound exercise and an isolation exercise for the biceps.
Specifically you are going to perform a set of 5-7 reps on chin ups, rest 10 seconds, and then immediately perform a set of incline dumbbell curls.
This is an absolutely brutal way to overload the biceps. The partial reps in the stretched position cause a tremendous amount of muscular damage and metabolic fatigue in the muscle.
Check it out:
Post-Exhaustion Biceps Routine
- A1: Close supinated grip chin ups, 5 x 5-7**, 2/0/X/0, 10 seconds rest
- A2: 30 degree incline DB curl (supinated grip), 5 x 7-9**, 2/0/X/0, 180 seconds rest
**Perform 4-6 partial reps in the stretched position after reaching failure.
You are going to have to dig deep on the incline dumbbell curls. It is much more difficult to perform post-failure partial reps on incline dumbbell curls than it is on other exercises such as preacher curls.
This does not mean it is impossible, just that it is more difficult. If you have what it takes to perform the post-failure partial reps on this routine then you will be rewarded with some screaming fast hypertrophy gains.
As my mentor Nick Mitchell once said, “train like a beast and you will eventually become a beast. Train like a maggot…”
Part 3: Isometronics
This training method is generally used as an intensification method to boost maximal strength levels. However, it still works awesome for boosting functional hypertrophy if you know what you are doing.
Here is a video of a full isometronics bench press workout. Don’t worry, we will cover how to perform this workout for your biceps in just a minute.
The procedure for performing an isometronics workout is pretty simple. You are going to need 2 pairs of safety pins for this workout. Next you take any barbell lift (such as bench presses, barbell curls etc.) and divided it into three separate ranges of motion:
- The bottom position
- The mid-range
- The top position
The safety pins should be about 4-6 inches away from each other in each position. You are going to perform 3 sets partial range of motion sets in each of these 3 different positions for 9 total sets.
For each isometronics set you are going to perform 4-6 partial range of motion reps followed by one all-out isometric contraction against the top pins. You should feel like you are trying to break the pins in half!
This isometric contraction is a great way to further fatigue your muscle fibers and achieve maximal muscle fiber recruitment.
After performing 9 total partial range of motion sets you would perform 1 full range of motion set for 6-8 reps to reinforce proper technique with the regular movement.
Here is what an isometronics bicep workout might look like. Check it out:
Isometronics Bicep Workout
- A1: Standing barbell curl bottom position isometronics (shoulder-width grip), 3 x 5**, 1/0/X/1, 180 seconds rest
- B1: Standing barbell curl bottom position isometronics (shoulder-width grip), 3 x 5**, 1/0/X/1, 180 seconds rest
- C1: Standing barbell curl bottom position isometronics (shoulder-width grip), 3 x 5**, 1/0/X/1, 180 seconds rest
- D1: Standing barbell curl, 1 x 6-8, 3/0/X/0, 180 seconds rest
- E1: Bilateral preacher zottman curl, 3 x 6-8, 3/0/X/0, 120 seconds rest
**On the 5th rep press against the top pins as hard as you can for 6 total seconds. You are trying to literally break the pins in half! After the 6-second isometric contraction lower the weight back down to the bottom pins and attempt one final partial rep.
You can click right here for a video of the mid-position isometronic set:
Yes, you are going to have to perform curls in the squat rack to perform this workout. For this reason I recommend you skip this workout if you train in a hardcore powerlifting gym.
They will probably kick you out of the gym on the spot if they see you “wasting” a squat rack like this!
If you train in a less busy gym and have access to an extra pair of safety pins then isometronics can be an AWESOME way to boost your biceps strength and size.
Just make sure you get plenty of rest after this workout. It can take quite a toll on your overall recovery ability.
As a general rule of thumb it is best to train with a full range of motion. Of course that does not mean that partial range of motion exercises are useless.
Partials can be a powerful way to stimulate further strength and size gains in advanced trainees. In this comprehensive guide I covered three of the most effective partial rep strategies for building big, strong biceps.
If you are stuck in a training rut then I highly recommend you give any of these routines a shot. The Larry Scott arm workout featuring post-failure partial reps in the stretched position of preacher curls is a particularly brutal routine.
If you are stuck at a biceps hypertrophy plateau then it will send you on a one-way path to swoleville!
“Challenges are what makes life interesting. Overcoming them is what makes life meaningful.”
Thank you for reading and I wish you the best of luck in your strength training journey!
The push / pull / legs split is one of the best training splits a bodybuilder can use. Many professional bodybuilders like Jeff Nippard have made it a core part of their training programs. If you...
There are many different ways to build your upper back. Many bodybuilders have built impressive backs using high-volume routines with lots of volume and short rest periods. However, in my...