Technique
Grip Width And The Trade-offs It Sets
Hand placement changes the distance the bar travels, the joint angles under load and which muscles contribute most, and no single width is optimal across all of those.

Grip width is treated as a preference and is closer to a mechanical decision. It changes several variables simultaneously, and each points toward a different width.
Wider grips shorten the distance travelled
In a press, a wider grip reduces the distance between the start and finish of the bar, because the arms describe a shorter arc.
Less distance for the same load means less mechanical work per repetition, which is why competitive bench pressers use the widest grip the rules allow.
That advantage is specific to moving maximal weight, and it does not follow that a wide grip is preferable for building the muscles involved.
Joint angles shift with the hands
Moving the hands outward increases the angle between the arm and the torso, which changes the demand at the shoulder and the contribution of the chest relative to the triceps.
A narrower grip keeps the elbows closer and increases the range through which the triceps work, at the cost of a longer bar path.
Neither is universally safer, though very wide grips place the shoulder in a position some people tolerate poorly, particularly with a history of shoulder complaints.
Pulling movements follow the same logic inverted
In a pull-up or a row, a wider grip reduces the range through which the elbow flexes and increases the demand on the muscles that adduct the arm.
A narrower grip allows more elbow flexion and a longer pulling range, which increases the contribution of the biceps and the range the back muscles work through.
Because the range differs, comparing performance between widths is comparing different exercises rather than measuring the same capacity.
Wrist and elbow position is often the deciding factor
Grip width determines the forearm's orientation and how much load passes through the wrist at an angle, which is where many pressing-related wrist complaints originate.
Elbow discomfort in pressing frequently improves with a modest change in width, because the change alters the line of pull on the tendons involved.
Since these effects are individual, a period of a few weeks at an adjusted width is more informative than any general recommendation.
Consistency again matters more than the exact setting
Small changes in width between sessions make performance comparisons meaningless, because the exercise itself has changed slightly each time.
Using the bar's markings to fix a position removes that variability at no cost, and it makes any deliberate change in width interpretable.
Choosing a width for a stated reason, then holding it for a block, produces information that random variation never will.





