I'm not disputing that sports science is a significant factor in performance, but I wonder if the old time riders tended to have more sheer brute strength? Their physical build would suggest they did. There's also the thing that a lot of people don't like to talk about, the effect of doping on athletic performance. I've recently been reading about Armstrong's exploits, and one thing that stands out in pro cycling is that average speeds in major events like the TdF increased year-on-year by more than could possibly be accounted for by training & nutrition advances alone. Much of that increase must have been down to widespread doping, such as the use of EPO. I'm sure cyclists and other athletes have always consumed the type of food & drink they believed would help their performance, right from the beginning of sports, but the scientific advances in recent decades benefitted the dopers just as much as the clean competitors. Knowledge is knowledge at the end of the day.