CPT spotlight

Are Partial Reps A Waste of Time?

Brad Dieter
Brad Dieter
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In the world of training, there are a lot of different ways to execute a given exercise. For example, a single exercise like a squat can have an almost infinite number of variations even though it may always be considered a squat.

There are regular back squats, pause squats, eccentric focused squats, 1.5 squats, slow-tempo squats, jump squats, box squats, banded squats, and a host of other variations on the core movement of squatting. The purpose of each of these different variations on the squat is to elicit a different training adaptation or change loading across the strength curve to change how the body experiences the movement. 

One other variation on a given exercise is known as a partial repetition, also called a partial rep. This article will take a deeper dive into exactly what partial reps are and if they are worth including in your training program.

What are partial reps?

Partial reps are a variation on a given movement that is performed precisely as it sounds, the exercise is performed over a partial range of motion. This partial range of motion can occur in the end-range of motion, the middle range of motion, or the most proximal range of motion. 

In many cases partial ranges of motion occur “on accident” by individuals because they may be unable to perform a given exercise through the full range of motion due to mobility limitations, the weight being too heavy, or just not fully knowing what the intended full range of motion for the exercise is. The type of partial reps that we are referring to here are a type of deliberate repetition that is limited in range of motion for a specific reason.

Why include partial reps?

At first glance it may seem like a bad idea to include partial reps in one's training as it is not fully executing a movement the way it should be executed. Which is true in many cases, however there are some very good reasons why partial reps may be a very beneficial tool to use in a program. There are three main reasons why someone may choose to use partial reps, improving position specific strength, hypertrophy, and training around injury.

Partial reps can be an excellent tool for building position specific strength. One of the most common examples where partial reps have been used effectively is to help with strength in the weakest position of the squat, the bottom.

Exercise such as box squats limit range of motion at end-range and prevent the “bounce” out of the bottom of the hole in squatting which can help individuals build more strength in those positions. Pin squats can do the same thing where they limit range of motion and require the individual to focus more on building strength in those weaker positions than in stronger positions. 

From a hypertrophy perspective, partial reps can make a given exercise more “effective” for stimulating hypertrophy as more time can be spent in the range of motion where mechanical tension is highest and the muscle is exposed to more metabolic stress.

One example of this might be bicep curls. While there is some stretch tension at the very bottom of a standing bicep curl, the lift is mostly unloaded in this position. As such, conducting including a few sets of partial reps were the lift goes from about 130 degrees of extension to full flexion instead of 180 degrees, can be a good tool for increasing the overall mechanical tension of that exercise. 

Another use for partial reps is to allow individuals to train specific exercises or movement patterns while injured. Many times, musculoskeletal injuries have position specific pain, discomfort, or weaknesses and programming an exercise to avoid those positions can allow an individual to still train that movement pattern and those muscle groups without exacerbating an existing injury. 

How to incorporate partial reps in your workout routine

There are many ways individuals can include partial reps in their training and there is no single way to apply partial reps, it should be really tailored to an individual’s training needs. However, there are a few principles to consider. 

The first would be to examine partial reps for a strength specific reason. If you are a coach who trains clients, or an individual who competes in strength sports such as powerlifting or weightlifting, partial reps may be considered for areas of an individual’s lifts where they may have weaknesses.  Consider looking at sticking points in their squats, bench press, deadlifts, or other major lifts and use partial reps to help train more position specific strength. 

Exercises such as box squats, pin squats, pause squats, and out-of-the hole squats are great exercises to consider programming for individuals who have difficulty with squatting out of the hole. For individuals who have a sticking point in their deadlift, you may consider rack pulls or deficit pulls depending on which position the individual struggles with. Board presses and partial rep bench presses may be options for individuals with key sticking points in their bench press. 

The second would be to determine if a client who is focused on hypertrophy may benefit from partial reps. If a client has had slower than expected growth or is having difficulty “feeling” lifts or “activating” muscles through a full range-of-motion exercise, partial reps can be a very effective tool for these clients. 

How to Put Partial Reps to Work

Here is a list of exercises that may be useful for partial reps from a hypertrophy standpoint. 

●  Dumbbell biceps curl - remove the bottom one-third of the movement. 

●  Lunges - stop about 60-70% of the way down to isolate quadriceps activation and activity.

●  Skull crushers - limit movement in extension to ~70% extension (do not fully lock out elbows).

●  Hanging leg raises - remove the bottom one-third of the movement and keep abdominals engaged the entire set.

●  Lying hamstring curls - remove the last one-third of the extension phase of the exercise and keep hamstrings fully engaged. 

It is important to remember that partial reps should be a part of one’s program but should not be the entire program. These should often be thought of as additional tools but not replacement tools. 

Partial reps vs full reps

Both partial reps and full reps are important in any well-designed training program, and one should not be used at the full expense of the other. A program of entirely full range-of-motion repetitions may be leaving some muscle growth and position specific strength on the table. Conversely, a program of entirely partial reps is going to compromise end-of-range strength and stability as well as mobility which can increase the likelihood of injury in some circumstances. 

The best way to view this topic is not necessarily partial reps versus full reps, but partial reps and full reps and finding the best ways to incorporate both into you training based on your individual goals and needs.

Summary

Partial reps are exercises that do not include the entire range-of-motion of a given exercise. These types of reps can be very helpful additions to training as it relates to improving overall strength and can be highly effective tools for hypertrophy and can allow individuals to train around an injury.

Partial reps should be included alongside full range-of-motion exercise and there should be a very specific reason for using partial reps and they should have a high level of specificity for a specific goal and outcome. Consider using partial reps as another tool in your toolbox to create highly effective and efficient programming.

The Author

Brad Dieter

Brad Dieter

Brad is a trained Exercise Physiologist, Molecular Biologist, and Biostatistician. He received his B.A. from Washington State University and a Masters of Science in Biomechanics at the University of Idaho, and completed his PhD at the University of Idaho. He completed his post-doctoral fellowship in translational science at Providence Medical Research Center, Providence Sacred Heart Medical Center and Children’s Hospital where he studied how metabolism and inflammation regulate molecular mechanisms disease and was involved in discovering novel therapeutics for diabetic complications. Currently, Dr. Dieter is the Chief Scientific Advisor at Outplay Inc and Harness Biotechnologies, is co-owner of Macros Inc and is active in health technology and biotechnology. In addition, he is passionate about scientific outreach and educating the public through his role on Scientific Advisory Boards and regular writing on health, nutrition, and supplementation. Find him on LinkedIn!