I’m a personal trainer with 15-plus years in the game and this is the one thing nobody tells you about working out

A woman trains in the gym with her female personal trainer.

I've lifted and set down more dumbbells, and written and rewritten more lines of copy about fitness, than I've had square meals.

Yet, lately, I've come to realize there is one thing I wish I had known when I first started out: not every session will be perfect.