Shelbyfv,
I am 68 and you are correct, but my desire to still be the most efficient does involve things like marginal gains. For me dropping two pounds and having a bit more energy is a big marginal gain at my age. And I don't envision my riding like I did 35 years ago. A single century is possible with some help, but a triple is out of the question. I am doing wishful thinking if I thought I could do a lot of miles at my point in life. But a reality thing is what I am trying to do. I want to keep involved in this sport which I love, and sometimes it may just be here in the forums. Smiles, MH