Week Five: Made to Run

This week has been one of change. I've made changes to my training format and now I'm making a change to my blogging format. Last week, as Viv and I were running together, she said "it just feels so natural, like we were made to do this." And so we are. So I thought I would dedicate a blog to why we humans are such good runners.

The vast majority of animals are good sprinters, but no good over long distances. Humans are unique amongst primates in their ability to run long distances. Our closest relative, the chimpanzee, has a fast sprint but can only cover up to 100m. We are also unusual amongst mammals, and even cursors, who are mammals that are specialised for running such as horses. While many mammals may be able to outrun a human at a short distance, at a marathon distance the human can outrun almost all other mammals, especially in hot weather.

This is because the greatest physical challenge in endurance running is thermoregulation, or more simply, body heat. Most mammals cease running after short distances because they cannot cool their

African cave painting of runners

core body temperature fast enough to avoid hypothermia. Meanwhile the human ability to sweat and the upright organisation of our bodies mean we can run long distances at a fast pace even in hot, arid conditions.
So how did we get this way?

Fossil evidence suggests that these endurance running capabilities developed around two million years ago when humans were still ape-like creatures living on the plains of Africa. We were already bipedal walkers by this stage and had been for around four million years, and we were called simply Homo, not yet having branched into Homo Erectus (yes, I may be giggling a bit here).

There are several theories as to why we started becoming better runners. We had not yet developed tools, but were omnivores so it is possible we obtained meat by scavenging. In this case, being good runners would have enabled us to scavenge carcasses from lions after they were abandoned, but before they hyenas arrived. This is still a practice amongst modern hunter-gatherers in East Africa such as the

A Bushman kills at close range

Hadza in Tanzania.

Another theory suggests that we hunted animals by pursuing them for several hours, driving the animal to exhaustion and hypothermia. The hunter could then kill the animal safely at a close range as it would have no effort to fight back. This style of persistence hunting is recorded amongst many modern hunter-gatherer groups, most notably the Bushmen of the Kalahari. Yes, The Gods Must Be Crazy. Great film.

It was also around this time that we grew larger, which meant it would take longer for us to dehydrate. We also began to lose our body hair and started to sweat. The human sweats more per surface unit than any other animal. This sweat is released onto a near-hairless body in an upright position. The upright position means the torso is placed where wind speeds are higher and temperature is lower. This positioning combined with sweating and hairlessness makes for a wonderful cooling system that allows us humans to avoid the problems of over-heating and hypothermia that restrict other animals when running. Brilliant.

As a great man once said, "Baby, we were born to run!"

Okay, that's enough academia for now. Hope you enjoyed the change of pace. Here now is the summary of my running week along with stats:

Three days of rain this week made me think I should join a gym over the winter months. The operative word being 'thought'. Might just buy a raincoat instead. Due to the days of inactivity, I decided to lengthen my runs and go along the Eastlink Trail. It is full of hills, but very picturesque and potent with eucalypts. Time to start on longer runs methinks, going to go for endurance rather than distance-based goals. Just like our ancient ape-like ancestors :)

Mon - 4.59km in 00:33:21

Tue - work

Wed - rain

Thu - rain

Fri - hangover

Sat - 11.71km in 1:55:27

Sun - 8.37km in 1:18:37

If you want to know more about what I've said here, check out these resources:

• Persistance Hunting by Modern Hunter Gatherers by Louis Liebenberg
• The Evolution of Marathon Running: Capabilities in Humans by D. Liebermah & D. Brambie
• The Origins of Us [Documentary series] by BBC, presented by Alice Roberts, episode one
• Why We Run by Bernd Heinrich