Melody
Exercise was my "vitamin" back in the 80's when I was struggling as a single mom, working full-time, and being the sole caregiver for two elderly parents. It gave me the stamina I needed to be able to throw in a social life as well.
The added benefit was it gave me an outlet after particularly frustrating/hard days at work. I could silently "beat up" whoever or whatever caused the frustration without anyone getting hurt. If it happened to be a problem with a co-worker or patient, I could go into work the next day and feel good without having to brag about my victory. As a result, I got along fine with everyone at work.
Having something or someone else accomplish a task for you isn't as personally satisfying as accomplishing the task yourself.