I just did a 70 mile 6000ft ascent bike climb and took me 6 hours, which for me is slow. It tends to want to hurt the thighs, if I push too hard they get cramp. That was after a period when I focused on walking, and did 20 miles/day 2 weeks ago, which tends to stress that wee muscle on the outside of the calf bone.
I would have to do Triathlons to keep all muscles strong. Too much effort.
If I focus on one of them I can get for example the 70 mile ride down to to the 4hr30m - 5hr type.
Protein. Sleep. Repeat.