Adding weight or loosing weight, it is 80% about your diet. If you want to be stronger, go to the gym.

I have recently lost 20lbs without changing my diet at all.
I got a dog (4 year old shiba inu) and walk her 3 to 4 times a day. That is the big change.... I do run with her a bit..we also chase some wabbits together... but she is as lazy as me...
I also sail about 10 days a month... the trap is my prefered (and only) situp I do, Raising the mast is the only "lifting" i do... sheeting in is my upperbody workout... and rum makes it all hurt less...