In more than a century of Olympic history, only world wars, by killing millions of people in their athletic prime, had previously caused this kind of stagnation.
So its return has inevitably raised the question of whether human beings are finally approaching the limits of physical accomplishment, after decades of unfulfilled predictions about such limits. Many athletes and coaches, and some scientists too, say the answer is probably yes.
To others, however, a less natural explanation is more likely. At least some of the record performances from the 1970’s and 80’s owe themselves to the miracle of drugs. Only now, after a decade of more effective drug testing, do athletes seem to be catching up to the steroid-aided results of the past, many Olympics watchers say.” (New York Times)