Will anyone ever run a two-hour marathon?

Thirty years ago, scientists calculated that the fastest possible marathon, in perfect conditions and with the perfect athlete, would be 1 hour 58 minutes. And we’re getting close. This September, Kenyan long-distance runner Eliud Kipchoge (below) set a new world record of 2:01:39 at the Berlin Marathon – a race ideally suited to fast times because of its flat course, few corners, and typically good weather conditions. Sports physiologists think that the two-hour limit could be broken in the next few decades, as a bigger talent pool of runners, plus advances in training technology, create ever more ideal combinations of athlete and running conditions.