You’ve been hitting the gym consistently, following your workout plan to the letter, and pushing yourself through every rep. In the beginning, the results were exciting—visible changes in the mirror, ...

Building muscle remains one of fitness culture’s most misunderstood pursuits. Despite countless hours spent in gyms across America, many people struggle to see meaningful changes in their physiques.

A. Fluorescent immunostaining of PDGFRα, showing mesenchymal progenitors, laminin surrounding skeletal muscle, and AR. Arrows indicate mesenchymal progenitors expressing AR, arrowheads indicate ...