A recent study reports
"Those who experience adverse childhood experiences may engage in the pursuit of muscularity to compensate for experiences where they once felt inferior, small, and at risk, as well as to protect against future victimization,"
I never been that worried about muscles but I have shown an obsession with martial arts, been studying since 7 have two black belts go ji and kempo a brown belt Japanese jujutsu two green belts judo and itf taekwondo.
The start was as an abused child I never wanted to be in the position where someone could hurt me again and I'd be defensless. I didn't associate muscles with protection from victimisation but having combative martial arts skills.
I rarely have had cause to use them outside of the dojo/ dojang but there have been moments. Did the amount of effort I put into being able to knock out grown men equal a worthy allocation of time. I think yes but I am sure others would disagree.