Originally Posted by
wphamilton
....Can we keep improving, but less and less, asymptotically approaching some line, where does that line move with respect to age? Beats the heck out of me, but I suspect that that also is a very individual thing.
You can bring your fitness to a peak (your peak) with a training program over 10-12 weeks.
Essentially intervals are stressful and sometimes us old guys are just not that motivated to suffer to that extent.
So how much can we improve our individual fitness? Depends on how hard we want to work and unless you're racing you're probably not going to be that motivated.