This is maybe the crux of the matter, you say "Moderate exercise does not count as stress, but regular vigorous, high-impact exercise does."Ludwig wrote:To return to the point: my understand is that, in general, anything that places stress on the body accelerates the ageing process. Moderate exercise does not count as stress, but regular vigorous, high-impact exercise does.
Well, that's pretty subjective. These days I can run 5 miles in 45 minutes with my heart rate only around 150. That can only be described as moderate, I can easily hold a conversation. Five years ago I wasn't fit enough to run 5 five miles without stopping even at maximum effort with a heart rate close to 200, it would been beyond vigorous.
One man's moderate is another man's vigorous.
Are your definitions of moderate and vigorous relative to your experience of life? Or of the African hunter gathers who evolved the bodies we're currently using for us? I suspect even keen amateur runners in the UK, those clocking up 20-40 miles a week say, would be considered positively sluggish in comparison to the amount of miles our ancestors clocked up.
In the last few generations out of tens of thousands of generations our physical activity has crashed catastrophically. Our bodies are not evolved to spend 10+ hrs a day sitting down. It is far more likely we are evolved to spent 10+ hrs a day on our feet, walking and running. Even keen amateur runners in the UK still spend a lot of time sitting down and only run for a few hours a week - that's nothing compared to our evolutionary history.
Sure, I expect there is a level of activity that damages the body over time. I just think it very high, 100 mile per week territory (which is still only 2hrs running per day). This distances even keen amateurs clock up are considerably below this.
