In 2013, Asics set up a treadmill ahead of the New York marathon to see how long people could keep up with the pace of the leaders. In British journalist Ed Caesar points out that endurance running is one of the comparative advantages of humans.
Late-race surges now have runners covering five-kilometre stretches at or quicker – a pace that that would once have won Olympic gold for the five-kilometre track event.Antipodean running buffs will appreciate that Caesar acknowledges two training traditions originating in our part of the world.New Zealand's Arthur Lydiard advised his runners to cover vast distances at a steady pace, while Australian running coach Percy Cerutty advocated brutal sprints, including up Portsea's sand hills. Kenyan runners eat a simple diet of ugali (made from maize flour) and local vegetables.They sleep a lot, and spend hardly any time in the gym or cross-training.In breaking the world record in 2007, one runner lost 10 per cent of his body weight.Another compares the sensation of running a world-beating marathon to holding your hand in a bowl of hot water while the temperature rises. Being born at altitude makes your lungs more efficient, while slender limbs help dissipate heat. Marathoners have always clocked up serious miles, but the leading Kenyan runners are pushing the limits out further, covering around 200 kilometres a week.
That means two or three sessions a day, typically on rough roads.
Today's top marathoners are often former 5k and 10k champions; Caesar describes them sprinting so fast in training that they would sometimes overtake his 50cc motorcycle.
In the early 1980s, I watched Rob De Castella running a race through the middle of Sydney.
At one point a teenager on the nearby path tried to run alongside him.
The kid was sprinting at top speed, but couldn't keep up with Deek for even a hundred metres.
Watching top marathon runners on television, it's easy to forget how blindingly fast they are.