When I came home from a "family umbrella hike" (
) this evening and saw your message, it brought a smile to my face
Hope you won't mind my answering it here publicly, but climbing the Mont Blanc and then paragliding down and then doing the Athens marathon
surely I am dying to meet you now, you are such an inspiration. A shame you "just" get to do the marathon now because of the knee injury.
I am answering you here because there are many specialists and coaches here who may have more experience/useful info than I have about knees and your local trails, but from my limited knowledge, if I were in your position I would indeed do some trails gently to maintain my CV fitness, of course within the limits set by my doctor. One idea is to ascend Rigi fully or partly like you suggested, but using small, fast steps
(rather than big power steps which can stress the knee too; think of the analogy of super-small gears for climbs), and then descend by cablecar or train. Rigi is conducive for barefoot hiking/running too, if that interest you. I do plan to do a few hikes there with my son in the coming weeks, and will share with you any tips on the trails on that side of Rigi (never been that side).
As for me, I am more of a beginner in mountaineering, but I have some ambitious goals for next year, possibly Weisshorn, and at the very least the Matterhorn Hornli route, if I stay here till then. Indeed, this kind of 10-12 hour endurance activity is an excellent way to train for these big Alpine summit days, for the fitness part. As part of my pre-training, this summer I will be staying a few days at Fluhalp
hiking at up to 3500m, this place is advertised as the highest normal hiking region in the world, then after acclimatising do an easier 4000er like Rimpfischhorn with a guide. I haven't asked anyone to join me yet, so anyone reading thi thread: I will be happy to have suitable partners for these 1-3 days of high altitude hikes (I can do the 4000-er separately but you are welcome to join me here too, if you meet the requirements), I haven't thought of the dates yet, but it will probably be early July, or end of July to coincide with my birthday.
Coming back to this event, it is no problem if you let us know your ability to join later on; it might be an idea that you join us for the last ascent, join our EF Mountain Athletes Social (ok, I just coined the name now, surely we wouldn't do the Social at a bar in Zurich, no?) that way you don't need to descend at all. Don't worry about "possibly" slowing the group, it will be a social thing.
Wish you a speedy recovery,