Mod Request / WCIF - No muscle gain from yoga

I've asked elsewhere for this mod but had no replies. If it already exists; Great! If not, I will be incredibly grateful for whoever decides to make it, or perhaps tell me in very basic terms how to do it myself.. If it's not super hard, that is.

Basically I'm looking for a mod that removes the muscle gain from doing yoga and replaces it with weight loss, or just removes muscle gain. I find it kinda unrealistic that sims get mad weight gains from performing yoga. 

Thank you so much in advance for any responses to this topic!