How lagging muscles get prioritized
Weak-point training, sometimes called bringing up a body part, concentrates extra attention on a muscle group that has fallen behind the rest of the physique. The usual levers are higher training frequency, more weekly volume directed at that area, and scheduling it earlier in a session or week when energy and focus are highest. Training a lagging part first means it receives the best effort rather than the leftovers.
The premise is that muscle responds to a sufficient and progressive stimulus, so reallocating volume and freshness toward the weak area can narrow the gap over time.
The tradeoff with overall recovery
Adding volume to one area usually means holding or reducing it elsewhere, because total recovery capacity is finite. Pushing extra frequency without managing fatigue can stall progress or raise injury risk, so the strategy works best when it is balanced against the rest of the program.
Muscle development is also constrained by genetics and individual structure, so some imbalances respond faster than others. This is general educational information about training concepts, not individualized programming advice.