As a newbie lifter or gym enthusiast, the term range of motion is either a little confusing or your bread and butter. I say this because, in the beginning, some people follow a pre-made plan or read/ watch a lot of content that focus on form, tempo, even primary and secondary muscles engagement per exercise. Thus, guiding them into one of the two groups above.
Saying range of motion is confusing may be an overstatement, so let me clarify this a little better. Using this label for this post entails following what someone else tells you per exercise and not understanding why; Ex: you must bring your butt as low as possible on a squat or your back must be majorly flat during bench.
Why does this matter?
That said, your most likely wondering why this is necessary information to understand if some plans don’t dive into depth about it anyway. The answer is a simple range of motion is crucial for proper form and time under tension (TUT). The form part is self-explanatory, but proper form aids in injury prevention, which is essential for long term muscle/ joint health. Not to mention keeps you in the gym consistently rather than taking weeks or months off to recover from an injury.
As for time under tension, muscles benefit from consistent tension throughout the movement. Thus yielding more strength, size and endurance gains rather than leaving some due to inferior ROM or improper form. Consistent TUT does not mean to grab a weight and pump out as many reps as possible all the time. Doing that will lead to a lot of fatigue which in turn leads to poor form or injury.
That said, I look at ROM as a factor of lower and upper body exercises. In terms of the lower body, full ROM is crucial for optimal gains. Since TUT stays consistent during lower body exercises, there is no real benefit to throw partials into the mix. Even though some bodybuilders may refute this statement, studies back the claim.
However, studies show that partials are beneficial during upper body exercises due to TUT inconsistencies. Exercises like the shoulder press, bicep curl, and lateral raise allow tension to dip at the top end of the movement or bottom, due to factors like lockout or gravity. Therefore, stopping just before the lockout is acceptable and even beneficial. Similar to hitting a few partials after failure at full ROM.
Now with all that out the way, I want to add my opinion and experience with ROM. When I first started lifting, it was full ROM, or my brain said “you’re cheating” in addition to my gym partner at the time.
However, now I think ROM is a tool to play around with especially in terms of the upper body. Since flexibility in our extremities varies, going a little further or shorter allows for more TUT and muscle activation.
That said, always make sure you can do a full range of motion with weight before trying to do partials or any other adjustments. You don’t want to be the trainee squatting 240 at 50% ROM and barely 200 at full.