As with everything in the fitness world, the two fronts here are belligerent and absolutely convinced that they are right. In the blue corner, you have the ” ass to grass” yelling veteran when someone is squatting , the red corner the vast majority of gym goers ( even some pro bodybuilders) who seem to be happy with doing partial reps because ” this way you can lift more weight”
But what is really better?
Let me entertain you with a little personal story. In my early twenties I fell victim to the power system by John Sysco, which promised that you would “grow like weed.”
It sounded very alluring, basically you where moving a very large tonnage for a very short range of motion, mainly the strongest part of the exercise such as the lock out of the bench, top of the curl etc. At the end of the week I would add up all the weight you lifted ( which was considerably more than I would normally do) and wait for my weed like gains.
After 4 weeks..nada zilch but a cool elbow injury. You can guess where this is going
In 90% of all cases full range of motion wins. Mainly, because it provides more of a stretch during the exercise.
Why is that important? During the stretch or eccentric phase fiber damage occurs which then in turn is causing repair work which means the muscle is being made stronger and bigger (bro speak :” you are on the gains train”).
Mathematically, full ROM can not be beat, as science will tell us since mechanical work is defined as distance x weight x reps.
Let’s look at a practical example: if you squat a weight of 300 lbs for 8 inches (a partial rep) for 10 reps, you’ ll end up with 24,000 lbs of work.
2. Overcoming sticking points. Sticking points can also be worked out with partial reps. If you are struggling with a certain aspect of an exercise ( bottom of the squat) partial reps will help you to catch up
3. To achieve complete muscle fatigue . That his one aspect where I use partials quite a bit. When a muscle can not longer perform of the full range of motion, there is still some strength left in the strongest part of the motion, which is usually around midpoint. Therefore adding partial reps at that point can add a nice little boost to the set AFTER you performed your full ROM work