Full range, ass to the grass, full range of motion, full reps, all the way down – all terms we generally hear in the gym.
How often do you hear or even see someone mention, partial reps? Probably not that very often, but this is a technique which could help take you to the next level.
Let’s break it down.
What are partial reps:
So instead of completing a full range of motion a partial rep is when you perform just a portion of a repetition, this can be half the repetition or even less than that.
So this can be compound exercises such as squats that only go down a few inches, or the top half of a bench press, or the bottom part of a bicep curl, or bottom half of a tricep pull down, these partial rep movements have been proven to generate impressive results.
This lifting technique helps to increase your maximum strength, and to overload all the fibers in your muscles.
A Japanese study from 2019 stated the Partial Rep Exercise (PRE) technique can ‘help(s) to increase your maximum strength, and to overload all the fibers in your muscles’ (1).
Another study looked at if a full range of motion induced greater muscle damage, than PRE, and it was concluded that ‘elbow flexion exercise with full ROM seems to induce greater muscle damage than partial-ROM exercises, even though higher absolute load was achieved with partial ROM’, which would seem rather obvious (2).
One further study looked into the effects of Range Of Motion (ROM) on muscle building developments during resistance training and concluded ‘that the response to variations in ROM may be muscle-specific; however, this hypothesis also warrants further study’. So Partials may be good for some body parts but not for others (3).
Now the most interesting study is from The University of Southern Mississippi.
The study itself utilized the bench press and was over a 10 week period where Fifty six ‘subjects were divided into 3 groups:
Group 1 (N = 11) trained with 3 full range of motion sets on the bench press.
Group 2 (N = 15) trained with 3 partial range of motion sets. (A partial repetition was defined as one that is beyond the sticking point 2 to 5 inches from full extension of the elbows).
Group 3 (N = 30) trained with a combination of partial and full range of motion sets. All subjects were pre- and posttested on the bench press through a full range of motion using a 1 repetition maximum. Each of the 3 groups demonstrated statistically significant increases in strength from pre- to posttest’. (4)
The most interesting conclusion is that ‘No differences were found between groups’ so essentially PRE produced the same effects as full range of motion exercises.
So as you can see there is a lot of conflicting research.
Here are the two different forms of partial reps.
PARTIAL REPS AT THE WEAKEST POINT
An example of this is the bottom of the bench press or the bottom of a squat. You would only lift the weight halfway up and then back down for each rep.
Some benefits of working within the weakest range of motion are that you will be using relatively light weight, therefore minimizing your risk of injury. Don’t be deceived by the light weight. Remember, you are completing all partial reps in the weakest range of motion.
This is where the muscles contract the hardest as they struggle to complete each rep. The weight may be light but the training is intense. Partials at the weakest point also allow for higher volume work.
PARTIAL REPS AT THE STRONGEST POINT
You may have heard of this as “power factor” training.
The theory behind this is that you work in the top half of the movement – the strongest point. This will allow you to lift maximum weight. Because there is no weak point, you will be lifting heavier weight than usual. However, there is a greater risk of injury when going heavy, so use common sense, warm up properly and get a spotter to reduce the chance of injury.
Bicep Curls: Partial Reps at the top, as tension is usually lost at the bottom of the movement.
Bench Press: Partial Reps at Top, this will add focus to the chest and take away secondary muscles such as triceps and front delt.
Squat: Partial at Bottom, this will ensure tension on the quads.
Deadlift: Partials at the bottom so you feel constant tension in the back of the hamstrings.
Tricep pulldown: Partial reps at the bottom as again this is to ensure tension stays in the triceps.
Potential Benefits of Partials:
Training through injury
Partial Reps can also ensure you are still able to train if injured, and not have to take an extended time out. As at times full range of motion can exacerbate certain injuries.
Increase Muscle Hypertrophy (?)
Partial Reps can allow you to perform for longer and to do more reps as you are not fatigued due to having to do a Full Range of Motion, and can increase muscle hypertrophy, as you are spending more Time Under Tension (TUT).
(As TUT, is the amount of time muscles are under tension and stress, and by doing so will maximize muscle hypertrophy)
So as you can see there is a lot of conflicting research on this subject and is not 100% conclusive but Partial reps can be great to break plateaus, workout while injured, change a routine, or even get used to a heavier weight but this should not be by eliminating full range of motion from your armory completely.
You should incorporate both full range and partial reps where necessary and possible. And the best judge to know if a partial rep is worth it or not is yourself.
An analysis of full range of motion vs. partial range of motion training in the development of strength in untrained men. Massey CD, Vincent J, Maneval M, Moore
M, Johnson JT. J Strength Cond Res. 2004 Aug;18(3):518-21.