What makes a repetition complete?
You see one person squat low and another stop halfway. Does the deeper repetition always win? The answer depends on the exercise, the goal, and which part of the movement the shorter repetition includes. “Full” and “partial” describe a movement range; they do not settle its value by themselves.
Range of motion means how far you move through an exercise. A deliberate partial repetition uses a chosen portion of that movement. That is a different decision from intending to do a full repetition and gradually shortening it as the set gets harder.
Deeper squats changed some outcomes, not all of them
In a 2019 trial, 17 men trained either full squats or half squats twice a week for 10 weeks. The full-squat group improved more in the full-squat maximum-strength test and gained more muscle volume in the gluteus maximus and adductors. Knee-extensor muscle volume increased in both groups, while rectus femoris and hamstring volume did not change significantly. [1]
That supports a specific point: the range you train can affect the result, and different muscles do not necessarily respond alike. It does not establish one ideal squat depth for every person. This small squat-training study also cannot tell us what happens with every bodyweight exercise.
Not all partial repetitions are the same
A 2025 study compared full repetitions with partial repetitions in the portion where the target muscles were more stretched. Twenty-five experienced trainees completed eight weeks of supervised upper-body training. Each person trained one arm with each approach. Improvements in measured upper-arm muscle thickness and lat-pulldown strength-endurance were similar. [2]
These were deliberately chosen partial repetitions, roughly half of each person’s full range, starting from the stretched position. Both conditions emphasized that position. The finding is not permission to replace any exercise with whatever small movement lets you count more reps.
The study measured specific arm muscles and a pulldown test, not every muscle or movement. Eight weeks and 25 participants leave uncertainty about longer-term differences. Training both arms differently in the same person may also influence strength results across arms. Useful evidence, with boundaries. [2]
Choose a range you can describe and repeat
Our practical suggestion is to decide what the repetition should look like before starting a familiar exercise. Use a range you can control without forcing a painful position. If a plan calls for a particular range and you cannot maintain it, pause or choose an appropriate easier variation instead of silently changing the task.
If you deliberately train partial repetitions, name the portion: “lower half” says more than “short reps.” Keep those sets separate from full-range sets when comparing sessions. That is a recording suggestion, not a claim that one range is best for you.
For your next session, choose one exercise and notice whether its start and end points stay consistent. If they change, record how. You will have a clearer account of what you practiced, without turning the deepest possible repetition into a competition.