Are you unwell though? It's kind of a chicken and the egg situation, being unwell will make you physically inactive, but being physically inactive will make you unwell. I'll never discourage someone from making any type of positive change, no matter how small. But I'm not gonna let people make excuses for themselves because the truth is, you'll do it if you want to do it. No one else is gonna make it happen for you.

I work in IT with a ton of stereotypical older overweight men who never exercise and eat like crap. Four have passed away in the past couple years (one just last month), one just had heart surgery, one is in the ICU right now. I see what having a strenuous desk job can do to you. It's hard watching it and losing people you care about. Please take care of yourself, your health is everything. Any change you can make is awesome... just don't tell yourself there's anything stopping you (again, unless you actually have an irreversible condition).