I want to ask that, in pull-ups do you actually lift your ENTIRE bodyweight for the same range of motion as you do in lat pull downs (like someone touching the bar on pull-ups and lat pull downs to their chin) or its slightly lesser because the COM (center of mass) is changing as the shape of your body changes while doing pull-ups from hands completely straight to bend at the top. It came to my mind because I have observed that in lat pull downs most people(including myself) can lift 5-10 kg lesser weight for the same reps as their pull-ups max reps. Obviously it depends on what movement you train more and the neurological adaptations as well. But for someone who does both, I have seen this case in MOST. Is the Range of motion in pull-ups actually lesser?
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Are you assuming the same hand position between the two exercises? Changing hand position affects how much the biceps and lats contribute to the movement.– JohnP ♦Commented Oct 14 at 19:19
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@JohnP I am assuming the same kind of grip in both exercises (same distance between hands, underhand or overhand etc.) same in both– Virender BhardwajCommented Oct 15 at 8:29
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I don't have any evidence to back this up but I would assume that you don't really lift your arms at least, since they are "attached" your equipment and performing the bending (sorry for the wording) but I don't know how much (in general) it would represent in percentage of body mass– KestrelPanicCommented Oct 15 at 12:21
1 Answer
Pull-ups and lat pull-downs differ significantly in mechanics and muscle recruitment patterns.
In pull-ups, the entire body is engaged as a single unit. Your core, shoulders, back muscles, and even legs work together to stabilize the movement. This additional engagement increases overall muscle recruitment.
Studies also show that Closed Kinetic Chain exercises like the pull-up (where one extremity of the body is fixed while the rest of the body moves) lead to higher motor unit recruitment compared to Open Kinetic Chain movements (such as lat pull-downs), resulting in more efficient muscle contraction.
In some machines the pulley ratio could also introduce mechanical friction. It seems on the machines with 1:1 ratio (only 1 pulley, so the weight on the stack is close to "true" weight) friction is almost negligible but it can be more noticeable on machines with more pulleys.
