Olympic runners could run more economically by just taking off their trainers, say researchers at Northumbria University.

In new research, Dr Michael Wilkinson found that when runners who always wear shoes run barefoot they immediately alter their gait to that characteristic of habitual barefoot runners, and also use less oxygen during barefoot running compared to running with shoes at the same speed. This indicates greater running economy which is an important determinant of distance running performance, especially in elite runners.

Habitual barefoot runners have a distinctive running gait -- using mid-foot landings, shorter stride lengths, faster stride rates, and less time in contact with the ground. They are also known to hit the ground with lower impact force and loading rates than runners who land on the rear foot in trainers. This cushions the force of landing, avoiding the discomfort associated with striking the ground heel-first common in runners who wear shoes.

In the study, a mix of 18 recreational and highly trained runners participated in a six-minute moderate running task both barefoot and in shoes on separate days. During the runs, oxygen uptake was measured to assess energy expenditure and gait was analyzed using digitalized video footage.

The runners reduced their stride length and ground contact time, increased their stride rate and, on average, used less oxygen during barefoot compared to shod running at the same speed, indicating greater economy. The 6% improvement in economy was the same as that previously reported after a nine-week training program for shoe-wearing runners, who also enjoyed a 3% improvement in running performance.

The results suggest that, by ditching their trainers, athletes new to barefoot running adopt a running style similar to experienced barefoot runners and enjoy an immediate and likely beneficial increase in running economy.

Dr Wilkinson is an expert in the physiology of exercise and a barefoot runner for more than six years, completing the Great North Run barefoot in 2011. He said: "There's a difference between shod and barefoot running gaits that comes about from feeling the ground. The sensory feedback when running barefoot encourages runners to put their feet down more gently in an attempt to avoid the impact forces that would cause discomfort and are also linked to injury.

"We saw a significant saving in energy from taking off running shoes. There were also mechanical differences in the foot strike pattern, with those who usually strike the ground with their heel first when they run with shoes, altering their pattern and striking the ground with the more cushioned mid-foot instead when barefoot."

Previous studies have found that populations who habitually run barefoot report a low prevalence of lower-limb injury, suggesting that plantar-sensory feedback (being able to feel the nature of the terrain and adjust the force your feet apply to the ground) plays an important role in safe running.

Dr Wilkinson and his colleague Phil Hayes will disseminate their research and the science behind barefoot running benefits to athletic groups in the North East this month.

Dr Wilkinson added: "Running barefoot is a hot topic in both running and scientific communities at present. High profile scientific studies have been popularized by the media reporting potential benefits of running barefoot for injury reduction and performance improvement.

"However, there is much misinformation being broadcast on the internet and in running magazines about barefoot running, little of which is based on current evidence from scientific investigations.