Wow its true your arms do matter when running. Maureen Roben, a running coach here in Denver, and I have been telling runners for years “your arms make a big difference” when you run. Now there is some scientific evidence to support our views.
Right here in our own back yard researchers at University of Colorado Boulder looked at the energy efficiency of runners with different arm positions during running. The runners were asked to run with arms at their side, behind their back, arms crossed over there chest and fingers intertwined behind their head. The results showed, as the scientists had expected, that the volunteers used the least energy and were most efficient when they ran normally, their arms swinging at their sides. With each change in arm position, their efficiency dropped. Holding their arms behind their backs required 3 percent more energy than running normally; draping them across their chests used 9 percent more; and parking them on their heads demanded 13 percent more energy.
How does this translate to you and your running? Remember your arms help propel you forward. Take some time to pay attention to what your arms are doing. I suggest on your warm up do a drill that will get you thinking about where and what your arms are doing. The one I like that best is at a slow running pace move your arms so that your hands are going from your hip up to chest level and back. Practice that for 300 meters or so. Then play with moving your arms faster and slower and see how that affects your pace.
Your arms can really impact your pace so practice perfect and start paying attention!