In the last column I talked about how humans are better at long-distance running compared to sprinting in practice.
Many animals are much faster than people when they sprint, clocking in at speeds that are two to three times faster than our Olympic sprint champions.
However, people can compete with the best long-distance animals at moderate speeds and even have been able to outrun and catch deer and zebra in open terrain and hot temperatures. First nations hunters needed to bring home sacred hides that were not be pierced by arrows, so they would chase these animals over hundreds of kilometres and over many days of hunting, running them to exhaustion.
So we know that people have done this as part of their cultural practices. But are there any remnants of evidence in our bodies that would indicate that we evolved to be great ultra-endurance runners? And if so, is this just a natural ability that came about as an outgrowth of walking upright or is it because we specifically did a great deal of long distance running as we evolved?
To answer this, let’s look at the skeleton.
It turns out that walking and running impose different demands on the bones and muscles. Running generates forces that can be as much as three to four times greater than walking. If we compare the surface area between the bones of the hip and knee we see that the joint surfaces are larger when compared to our nearest relatives in the ape family, and this comparison carries on to other running mammals when adjusted for overall body size.
Larger joint surface areas are required to dissipate the higher forces generated when running, so we did a great deal of running to survive as we evolved.
The bones of the legs pose an interesting puzzle. Longer, more massive bones and muscles that humans have provide a greater ability to run than other primates, but it would normally cost more energy to move these larger limbs. So we have adapted a number of energy-saving measures to counteract this. The thigh bone (femur) is certainly long, but the bones of the lower leg and foot are smaller relative to body size than other primates and running mammals. For example horses and other ungulates have much longer and more massive ankle, foot and toes which are drastically reduced in humans. All the bones from the knee joint to the ground are foot bones – ungulates essentially run on their toes and toe-nails.
Humans have five per cent less foot mass than chimpanzees, who require more massive feet for gripping and climbing and not for long distance running.
This reduction in human foot mass doesn’t make walking any more efficient, but it does produce substantial energy savings for endurance running. Humans also have a narrower pelvis compared to other running mammals which makes us less agile (agility is important for sprinters to catch prey or avoid being caught), but better long-distance runners. It’s like the difference between a vehicle that has a wider wheel-base, or “track”, that is more manoeuvrable, and one with a longer wheel-base that is less manoeuvrable, but tends to sustain forward momentum more efficiently.
All these adaptations in bone structure when compared with our ancestors and cousins in the ape family as well as other sprinting and endurance animals show fairly strong evidence that we evolved to be much better ultra-endurance runners as opposed to sprinting animals and this running ability adapted separately from walking.
I personally find the fact that we are evolved endurance runners very inspiring and motivating because if our ancestors were ultra-endurance athletes, that means that we should not be perturbed about going out for a 30- or 60-minute run each day.
Endurance running is in our bones – figuratively and literally. There is even more evidence for endurance running in humans that shows up in our muscles, tendons, and heat regulation systems.
More on that next time.
Kerry Senchyna holds a bachelor of science degree in kinesiology and is owner of West Coast Kinesiology in Maple Ridge (westcoastkinesiology.com).
