I started programming professionally at 16. I ran my first mile at 46. I'm 62 now and have run quite a bit. There's a very good (IMO) podcast that is mostly interviews of runners over 60[0]. At least one of his early interviews was with a woman who also finishes Ironmans. Disclosure, I'll be interviewed a week from today, although I don't know when it'll be published.
[0] https://www.youtube.com/@RUNLONGAFTER60/podcasts