Washington: A new study has raised doubts over the minimalist running shoe movement, which may have prompted people to ditch their running shoes.

Researchers at the University of Colorado in Boulder evaluated 12 barefoot runners on a treadmill sporting lightweight shoes or nothing but lead strips taped to their bare feet.

The results were surprising as the researchers found that running barefoot provided no physiological benefit in efficiency.

In fact, runners used 4 per cent more energy per step when running barefoot, the Discovery News reported.
"Running barefoot offers no metabolic advantage over running in lightweight, cushioned shoes," the researchers concluded in the study.

Earlier studies have suggested that running barefoot is easier as there is no added weight.

But that thinking does not take into consideration every variable, including the cushioning that shoes provide.

If people are not wearing shoes, the researchers believe, their legs absorb more of the impact of running, causing them to work harder.

"What we found was that there seem to be adaptations that occur during the running stride that can make wearing shoes metabolically less costly," Jason R. Franz, who led the study, told to daily.

The "barefoot" runners in reality wore thin socks to maintain hygiene and safety, and the shod runners wore Nike Mayfly lightweight shoes.

"There is some evidence that shoe design characteristics other than mass may influence metabolic cost," the authors wrote.

"Thus, we selected this running shoe in particular because it has some cushioning but no other features such as medial posting/arch support or various other motion control elements," they added.

The study has been published in Medicine 'n' Science in Sports 'n' Exercise.