Leg day, arm day, ab day—but what about lat day? Lats are the largest muscles in your upper body and the core of any workout routine. Most people use the term lats, but the scientific name for the lat ...

Train all five major back muscles with this complete breakdown. From lats to erectors, get exercises, recovery tips, and programming insight for serious back growth.

“Back day” has become a staple of fitness social media, often framed through aesthetics alone.