Partial vs Full Range of Motion for Muscle Hypertrophy

Whether you’re a gym enthusiast or a weekend warrior, you’re undoubtedly familiar with the argument for and against PROM (partial range of motion) training and whether or not it is superior to FROM (full range of motion) training.

Regardless of which resistance exercise philosophy you subscribe to, it’s important to note that there are specific recommendations, which are backed by science, that suggest that employing measured intensity, volume, and time under tension will yield desirable results.

In this article, we will detail some of the fundamental differences between full-range-of-motion versus partial-range-of-motion, enabling you to make an informed decision concerning your individual health and fitness journey. 

PARTIAL OR FULL RANGE OF MOTION FOR MUSCLE HYPERTROPHY

Although there is no hard data to support the benefits of one form of resistance training over the other, full-range-of-motion and partial-range-of-motion exercises can both influence dynamic and multiplanar patterns of movement, resulting in optimal muscle force production.

So what is muscle force production? It is a term commonly used in kinesiology to describe the relationship between the force and speed of a muscle contraction relative to overall power output.

As you’re reading this article, you’re probably thinking this all sounds entirely too scientific, but it should be noted that we are talking about the human body, which, in itself, is a scientific marvel of sorts.

That being said, what can the everyday man or woman distill from all of this scientific data? Well, the take away from all of this, is that time under tension, muscle activation, and hypertrophy are the things that should command our attention while performing a bench press, squats, overhead presses, and any other exercises that target a specific muscle or muscle groups. 

A STUDY ON EFFICACY

To further contextualize the great debate between the efficacies of full-range-of-motion versus partial-range-of-motion, also known as full or partial reps, lets take a look at a study found in the Journal of Strength and Conditioning Research, which shows not only the differences between the two forms of resistance training but also the glaring differences.

The study, which was conducted in 2012, was comprised of two test groups performing seated machine biceps curls; it’s important to note that neither of the participants in either group were professional athletes.

That aside, group “A” performed their bicep curls using a 0–130° range of motion, which is on par with a full-rang-of-motion curl. Conversely, group “B” performed their bicep curls using a 50–100°, constituting a partial-range-of-motions.

The study, which was conducted over a 10-week timespan, concluded that there were no appreciable differences between either test groups with regard to hypertrophy.

The study did find, however, that group “A” did see marginal strength improvements as a result of employing a full-range-of-motion during their exercise routines over that of group “B.” However, in the end, hypertrophy, which was the focus of the study, was the same across both groups.

In summation, the research suggests there may be no "optimal" range of motion when it comes to resistance training for hypertrophy. And it is likely, the variables to prioritize are things like technique, time under tension, training volume, load, etc.

My personal opinion is that both methods, of full and partial range of motion, should be deployed. If you spend too much time dedicated to partial range, it seems possible that you could be creating maladaptive plasticity which may negatively influence your movement patterns and gait. However, if you deploy full range of motion to "recover" from those partial reps and "remap" for the brain how much range of motion your joints have and how to contract the corresponding muscle fibers, I think any maladaptive plasticity can be prevented.