Negative Chin-ups
Chin-up negatives use only the eccentric (lowering) phase. You get to chin-over-bar with a step or jump, then lower extremely slowly. Negatives are among the most effective ways to build pull-up strength when you cannot yet complete a full rep.
Why they work
Muscle can handle ~20-40% more load eccentrically than concentrically. So even if you cannot pull up, you can control the descent—and that eccentric work drives powerful strength adaptations.
Execution
Get to the top chin-up position (chin over bar) with a step or jump. Supinated grip at shoulder width. From the top, lower as slowly as possible (goal: 5-10 seconds) to a full hang with arms extended. Step down and repeat.
Technical key
Do not drop or yank. The descent must be smooth through the whole range, especially at the end when arms are nearly straight (where many lose control).
Goal
3×5 negatives of 5+ seconds before attempting full chin-ups.