Why do my muscles ache the day after a big workout?

This post has been updated. It was originally published on July 31, 2017.

Ever woken up the day after a workout and wondered what you did to deserve such pain?

I’m talking about muscle soreness. That pain can stem from several sources, and understanding what’s behind yours will help you best remedy it—and find ways to potentially prevent it in the future.

Why is my body in so much pain after a day at the gym?

“There’s muscle soreness that could be due to, say weight training, which can cause what we call delayed onset muscle soreness, which is kind of a…