Working out

Hmm in my opinion, if your motivation to work out is the mental boost, I'd say go for an exercise or sport you might enjoy :) so it doesn't necessarily feel like a chore.

I agree with stefkal3x, I guess weight training should work?

idk what the best exercises are but i‘m also slim and have a fast metabolism. I did rowing tho for a long time and besides rowing we did a lot of weight training and also running for the endurance. And I actually gained some weight through building up some muscles but i must say that it was quite hard for me to build them up (probably bc of the fast metabolism). So maybe some weight training if that’s something for you? It can take a while tho until you see some results or maybe that was just me training 6 to 7 times a week while being a teenager who maybe ate a lot but maybe not the right stuff for so much training (being a vegetarian i probably would’ve needed some more protein). Also if you want to do it for your mental health it always should be some exercise you also kinda enjoy doing (I‘d personally choose running bc that helps me regulate best or if i‘m not up for exercise just taking a walk in the forest preferably helps me too already). But I guess as long as you don’t train too much (just listen to your body) it doesn’t really matter that much what exercises you’re doing. Sorry for the long text didn’t intend to write that much…

Strength. Anything weight training. Cardio 30 minutes max.