During her colourful career as a track and field athlete, Zola Budd was as famous for her eccentric habit of running barefoot as she was for turning her back on apartheid South Africa.
Now, scientists have found that running without any footwear could in fact be better for your legs than jogging in trainers, because it encourages the use of a different set of muscles as well as a different gait that avoids repeated heavy impacts between the feet and the ground.
Wearing modern trainers encourages heavy "heel-striking" between the back of the foot and the ground, whereas barefoot running makes people more "springy" and less likely to hit the ground hard with their feet, it is believed.
The researchers found that running in bare feet – which was until relatively recently in human evolution, the natural way to run – may give better protection against the sort of repetitive-impact injuries caused by striking the ground with a force equivalent to several times a person's body weight.
A study which compared barefoot runners with those who ran in modern trainers found that heel strike was less likely in those who did not wear running shoes. Barefoot runners were more likely to land on the front part or ball of the foot, and they adjusted their leg and foot movements so that they landed more gently on the ground, the scientists found.
"People who don't wear shoes when they run have an astonishingly different strike. By landing on the middle or front of the foot, barefoot runners have almost no impact collision, much less than most shoe runners generate when they heel strike," said Daniel Lieberman, professor of human evolutionary biology at Harvard University.