If you're looking to conserve more energy while running, the key could be to simply swing your arms more. A new US study has discovered that effective arm swinging can reduce a runner's metabolic losses by as much as 13 per cent. (As an added bonus, it also makes you look like Robert Patrick in Terminator 2.)
Whether you're participating in a long-distance marathon or fleeing from an axe-wielding maniac, there's a pretty good chance that you swing your arms while you're running. It turns out this isn't just human habit -- in addition to assisting with balance, swinging your arms also expends significantly less energy.
To test the impact of arm swinging on the metabolic cost of running, researchers from University of Colorado recruited 13 running enthusiasts from the community to use a treadmill in a variety of running styles. The participants' oxygen consumption rates were measured as well as the amount of carbon dioxide they exhaled. They found that the upper body movement caused by arm swinging decreased the metabolic cost of running.
This was due to each runner compensating for the loss of their counterbalancing swinging arms by increasing the amount that they swivelled the upper body. Whether they were consciously aware of it or not, each runner compensated in a very similar way by increasing the amplitude of their torso rotation.
"In summary, we find that arm swing reduces the demand for net metabolic power during human distance running," the report concludes.
"We also find that when arm swing is restricted, subjects increase the peak-to-peak amplitude of both shoulder and pelvis rotations, which likely explains the greater demand for net metabolic power. Our data suggest that actively swinging the arms provides both metabolic and biomechanical benefits during human distance running."