Cable

A dumbbell or a barbell both go slack at the exact point where gravity stops pulling on the weight — the arm nearly locked out, the hip nearly at the top — but a cable doesn't: it keeps pulling on the muscle through the whole range, from the first inch of the rep to the last. On the triceps pushdown, that means the triceps never gets a break inside the set, not even at the point where a barbell press would have already stopped demanding anything from it. The lat pulldown and the seated cable row use that same advantage for a back pull, and add another: a cable lets you change the angle of pull without switching machines, something a fixed bar can't do. That continuity comes with a double cost — there's no cable stack to carry out of the gym, and of the five it's the one that moves the least total load, so it isn't the tool for chasing a single maximum lift.