video transcript

Roger Kram is running to confirm that his theory is correct. He says that people who believe running barefoot is more efficient than running with shoes...are wrong. Kram, the director of the locomotion lab at the University of Colorado and doctoral candidate Jason Franz, have recently completely the most detailed study to date comparing barefoot running to running with shoes. The pair monitored the breathing of 10 experienced barefoot runners in their lab while they wore lightweight running shoes and compared those results with the readings taken when the runners were tested barefoot. (SOUNDBITE) (English) JASON FRANZ, DOCTORAL CANDIDATE, UNIVERSITY OF COLORADO, BOULDER, SAYING: "We measured the rates of oxygen being consumed and carbon dioxide being produced while these runners were running on our treadmill. And we could quantify the metabolic cost of the runner for all of these conditions." Running shoes are an added weight to a runner. More weight should result in the runner going slower or burning more energy to keep the same speed. But Kram and Franz found that their test subjects were running 3 to 4 percent more efficiently when wearing the light weight shoes. (SOUNDBITE) (English) JASON FRANZ, DOCTORAL CANDIDATE, UNIVERSITY OF COLORADO, BOULDER, SAYING: "Three to four percent is a considerable difference in metabolic cost. It is noticeable. In terms of a competitive runner who wants to run faster with less effort that 3-4 percent savings is important." Roger Kram says the cushioning in the sole of a running shoe is the key. The cushioning reduces strain on the leg muscles which offsets the added weight of the shoe. (SOUNDBITE) (English) ROGER KRAM, DIRECTOR OF THE LOCOMOTION LAB AT THE UNIVERSITY OF COLORADO, BOULDER, SAYING: "Some people feel that putting anything between their foot and the ground is a bad thing, that it reduced their ability to sense the ground and while I agree that it does reduce your ability to sense the ground it also means that when you have some material there, you have some cushioning that you don't have to use your muscles as hard to soften the impact." The researchers want to conduct further studies to find the perfect cushion to weight ratio for that perfect run. They also want to take a closer look at the track. ROGER KRAM, DIRECTOR OF THE LOCOMOTION LAB AT THE UNIVERSITY OF COLORADO, BOULDER, SAYING: "One idea we have is that you can create an ideal running track that might be faster than existing tracks and that would be if the track provided cushioning than the competitors could run barefoot or with even lighter shoes that just has spikes and nothing else and they could run more efficiently and maybe run new record times. " Kram admits there's no chance of a new track in time for this year's Olympic Games in London, but he does have advice for the competitors - find the lightest shoe possible and let the cushion do the rest. Ben Gruber, Reuters.