Running barefoot is hardly new. In 1960, Ethiopian runner Abebe Bikila ran the Olympic Marathon barefoot and, until the 1970s, most runners wore sneakers with a minimal amount of padding.
Kuegler says people are reverting to barefoot running for a number of reasons. For serious runners, there's the energy efficiency factor: when running fast, it helps not to be carrying extra weight. Casual joggers can run further and more comfortably by avoiding heel striking - that large, sudden collision force that leads to joint injuries and shin splints.
Barefoot running forces a technique improvement that can otherwise be hard to achieve.
If you compare the styles of someone running barefoot to someone in shoes, the difference is obvious. A barefoot runner lands on the front of the foot, under the body's centre of gravity, and pushes off from the toes. A runner in cushioned shoes usually lands hard on the heel, effectively stopping the momentum of the body. Take away the shoes and landing on the heel no longer feels comfortable or natural.
Kuegler says: "If you're in bare feet, the harder the surface, the lighter the landing has to be. People in minimal shoes learn a lot about the way they move."
Barefoot runners have to focus on their technique. Kuegler trains triathletes and says while most get help for their swimming and cycling, few have ever had any help to ensure they are running correctly.
"It's just one of those things people expect everyone knows how to do."
The world's fastest runners have a style similar to those running without shoes, whether they are shod or not, because the fore-foot landing style requires less energy to keep up the pace. Kuegler says changing to minimal, or no, shoes has improved his running speed.
But Kuegler cautions against immediately dumping your running shoes.
"Just stripping shoes off won't make a huge difference." It's important to ease into it and build strength in the calves and feet if a runner has always been a heel-striker.
The running without shoes motion requires lengthening of the leg muscles, which can take some getting used to.
Kuegler advises his clients to start with a 1km run in bare feet first, no matter how fit they are. "The muscles are stretching out and doing more work with every step. You're essentially using muscle that hasn't been used before."
It won't be comfortable at first. "If you take an injured runner and strip the shoes off and go for a run on a hard surface, they'll end up in more pain than if they just carried on. You must be cautious."
Kuegler says there is no shortage of information available for people thinking about switching to bare feet. They can turn to the internet, podiatrists and chiropractors. Barefoot running workshops are also held throughout the country.
Bruce Baxter, president of Podiatry New Zealand, agrees people need to be careful.
"It's not just a question of taking your shoes off, but whether your running is actually any better without shoes," says Baxter.
In many cases it is possible to improve posture and technique without removing your shoes entirely. And people with foot problems should be wary of ditching all support. "The most sensible thing to do is to be examined first," says Baxter.
