While I fully agree that continuous improvement is a laudable aim and it is good for the mind and the body to try to perform as well as we can for as long as we can, there is no getting away from the fact that performance eventually degrades with age for all of us, albeit at different rates for individuals.


Yes, there can be periods of improvement over the (relatively) short-term in older-age due to a variety of reasons such as training, technique, will-power, taking something more seriously in older-age etc., but the reality is that the direction of the performance graph is steadily downhill - possibly with a number of blips depending on the individual.


I think the data given in this thread for running, cycling and swimming does help to answer the op's questions.


I know this may come over as negative but I really don't mean it to. In my view it is ultimately futile to try and compare current performance to that of ourselves decades ago but we should always try to be that bit better than we were yesterday. I do, even though I don't always succeed.


Those blips can be very satisfying.