The same lifts that build muscle also build the mobility gains most people chase in stretching class.
If mobility is a goal, this is the most time-efficient answer the literature has produced.
TL;DR
Lifting through a full range of motion improves flexibility as much as static stretching — and builds strength at the new range on top.
What the study found
Morton's group randomised trained adults to full-range resistance training, static stretching, or a control. After 5 weeks, the lifting and stretching groups gained equally in hamstring and hip flexibility — but only the lifting group also gained strength through that new range.
How to apply it
Slow the eccentric phase and load the bottom range: deep squats, Romanian deadlifts to a strong stretch, push-ups, full-range chest flies. That builds mobility and strength in the same time slot. Save dedicated stretching for injury rehab or if you enjoy it.
Caveats
Very short-range partial reps still have their place for advanced lifters. But if flexibility is the goal, full ROM lifting is the highest-value option most people miss.
Effects of full range-of-motion resistance training on flexibility and strength
Morton SK et al. · 2011 · Journal of Strength & Conditioning Research
Trained subjects who lifted through a full range of motion gained as much flexibility as those who only stretched — and gained strength on top. End-range loading is the most efficient mobility lever.
Read the full paper