Is there a reason for not joining a gym? I don't work out at home because I would 1) Destroy the garage floor (It's concrete slab), and 2) buying all of that equipment just doesn't seem cost effective.
The unpredicted benefit is that you will socialize. I hate dealing with people in person, but even I have formed a few friendships at the gym. Like-minded people who are "outside of the rest of your circle" can be valuable connections, especially as we age. I do not know your age, but I'd like to think that if you are retired, you are older than myself, and I am already seeing advantages to cultivating multiple social circles, small though they may be.
The unpredicted benefit is that you will socialize. I hate dealing with people in person, but even I have formed a few friendships at the gym. Like-minded people who are "outside of the rest of your circle" can be valuable connections, especially as we age. I do not know your age, but I'd like to think that if you are retired, you are older than myself, and I am already seeing advantages to cultivating multiple social circles, small though they may be.