Peak? After school rugby and social squash, I started running v modestly at 33 and all my PBs [5 miles to Marathon] except 5k (too short, too fast, too painful) were set in an 18-month period when I was aged 48-49.
Nessie, I'm short of succession planning. i.e. what I would do with 45-50- more hours a week to occupy. With a little less loading, I could still go on finding teaching fun. I need to gather more intel [hate that abbrev. ]