I like walking too. I got an insane amount of exercise yesterday just by power walking in the sun/heat. It was a 40 min power walk, but I underestimated the time, distance, and heat. (I only wanted to do about a 25-30 min slow walk, but for some reason, I decided to power walk.) I was sweating like a pig, even with a hat on to block out the sun. TONS of sweat dripping into my eyes. It was pretty gross... not gonna lie. But I didn't regret it.

I would try water aerobics, except I have a skin condition on my back that I'm embarrassed about. So I'd look pretty awkward if I wore a shirt in the water to cover it... and even worse in a wet suit. lol. It's a great idea, though. I used to loooove swimming. Very relaxing and requires a lot of strength because of how resistive water is.

I'm only 27, so I guess I'm not as "mature" as you're probably talking about, but I would have no problem doing water aerobics or anything that. I couldn't care less about the ages of people who do them or the "dorkiness." Exercise is exercise. If people want to make fun of it, then fine. Enjoy being a couch potato or enjoy limiting yourself. If you say you don't like something without even trying it, then you're missing out on something you may really like.