The expression you can't outrun your fork has hit me hard. I'm up 30lbs since I started running a decade ago, some of it's muscle, but most is I just need to eat better.
It’s for sure my diet. I eat alright, but really suck at dieting, which is why I took up running nine or so years ago. It was great at first and I lost 70lbs but now I’ve gained at least 40 of that back and still running a lot.
I just didn't gain weight all of my life until my 40s no matter what I did, so I think that's just y/our biology.
From what I've been hearing lately, exercise might not cause you to lose much weight. There was a kurzgesact video giving a vulgarisation about it anyway, so take that as you will.
But exercise is still really really good for you, especially your mood. Just don't count on it alone if you have other body goals
There's a new theory going around that we age stepwise at 44, 60, and 78. Plus/minus a few years, individually, because biology is fuzzy.
And exercise isn't very good for weight loss. There's about the same calories in a 15 minute run as a 12 oz beer or a 30 gram "serving" of potato chips.