The 30 miles took me over 400 miles so far this year in 2 months + 2 days and on checking on my return this wasn't far short of the 530 miles I ran in total in the 4 years 2018 - 21. The four years included 102 races and I won my category in 30% so I wasn't just walking round with the sweepers. However in those 4 years I cycled 9700 miles which presumably helped me keep reasonably fit with little damage to my knees.
So my general suggestion is that if you aspire to do Wasdale at 90 years cut out fellrunning and all that knee damage, apart from actual races, and do more bike riding.
