A new meta-analysis published in the Journal of Strength and Conditioning Research looked at lifting vs. stretching programs to see how they compared when it comes to flexibility.
36 articles were reviewed, which included just under 1500 subjects, and showed that resistance training probably improves flexibility to a similar degree as stretching alone. “Probably” is doing some heavy lifting in that sentence, as the included studies vary significantly by design and subsequent statistical analyses doesn’t make this claim a slam dunk to fellow nerds.
Still, these findings corroborate another recent meta-analysis of the topic. Of note, this other meta found that lifting increased flexibility as much as stretching, except if the lifting was calisthenics. Sorry, bodyweight kings.
Overall, these findings provide more support that lifting increases flexibility in the range of motion trained. Whether it’s better than stretching is less clear due to study design, but it doesn’t appear to be significantly worse. My personal feeling is that most dedicated flexibility training that isn’t used for allowing someone to be active, e.g. desensitization, is a poor use of training time. I think people place far too much importance on flexibility as a marker of health and/or fitness.