> I do feel that 30 year old me would definitely be in better shape to chase kids around.

Can confirm that starting at 30 makes it relatively easy to keep up. Still not early enough though. Wish I’d started at 25.

It’s mostly a matter of effort though. You’ll become very good at it out of sheer need if you genuinely want to keep up. In far better shape now than I was at 30, mentally and physically.