New Study Shows Minimal Shoes Increase Leg and Foot Muscles

New Study Shows Minimal Shoes Increase Leg and Foot Muscles

A New Study From Harvard and PolyU Reveals Minimalist Shoes Make Your Legs and Feet Stronger, Decrease Chance of Injury

The public debate over minimalist shoes has been on a roller coaster for several years now, but perhaps not for much longer.

Although minimalist shoes for kids have been popular for several decades (we've made a business of it since 1985), the idea that adults—especially runners—could benefit from them erupted in 2009 with the publication of the book Born to Run. Runners began kicking off their shoes to hit trails barefoot and almost overnight every shoe company on the planet jumped on the bandwagon with a wide range of minimal designs.

All seemed well and good for minimalism until 2014 when Vibram, maker of the infamous 5-fingered toe shoes, lost a class action lawsuit after they were unable to support their advertising claims, which stated that their shoes improved foot health and prevented injury. The backlash of that verdict caused many people to flip their views on minimal footwear when headlines like these rocked the internet:

  • Proof Those 'Barefoot' Running Shoes Are BS
  • Barefoot Running Heads Into the Sunset
  • Time’s Up, Barefoot Runners. Make Way for Fat-Soled Running Shoes

That fallout was frustrating for a couple reasons. Firstly, Vibram didn't lose the lawsuit because their claims were proven false, only because they made a profit on claims that were not yet proven to be true, and this point was largely missed by the critics. Secondly, we've seen hordes of people coming through our shop who tell us their bunions cleared up, their hammertoes flattened out and their plantar fasciitis pain disappeared after switching to our shoes and throwing away their orthotics. It's hard to ignore that kind of response, and this new resentment toward minimal shoes may have scared away people who could have found relief for their pain.

We think the fact that our sales and customer base have continued to grow in spite of the Vibram lawsuit is a testament to the benefits of minimal shoes (we're currently in the process of moving to a bigger workshop to meet increasing demand). We've always taken the attitude in our shop that the pendulum will eventually swing back our way as research continues to emerge. Sure enough, every month we hear from more podiatrists, biomechanics and fitness trainers who tell us their clients are improving mobility and foot health after changing from conventional trainers to our shoes.

This month, a new study came out in strong support of minimal footwear, and one that may have saved Vibram from their lawsuit had it been published a few years earlier. Conducted by the Hong Kong Polytechnic University (PolyU) and Harvard Medical School, this study took 38 runners, men and women with a median age of 35, and put them through the ringer.


Dr Roy Cheung (left), Assistant Professor in PolyU’s Department of Rehabilitation Sciences, and Miss Wylie Tsang (right), participant in the research. Photo credit: The Hong Kong Polytechnic University

The subjects were separated into two groups: one group of 20 who trained in minimal shoes and another control group of 18 who completed the same training in conventional shoes. The minimal shoes contained no heel-to-toe drop and flat insoles with no artificial cushioning or support, whereas the conventional shoes featured a heel-to-toe drop over 5mm with added cushioning and arch support. Both groups followed the same transitional strength training regimen, which included calf and balance exercises. The participants were given MRIs at the start of the study and again after 6 months of training to measure the muscle volume of their legs and feet.

The results were stunning.

On average, the muscle volume of extrinsic foot muscles (between leg and foot) increased by 7.05% among the group that wore minimal shoes, and their intrinsic foot muscles (between heel and toe) increased by a whopping 8.8%! Furthermore, there was a correlation between the subjects' compliance to wear minimal shoes and the results, meaning that the more compliant people were to wear minimal shoes, the greater the muscle volume growth.

The volume of leg and foot muscles in the control group, who wore the conventional shoes, showed no improvement.

Infographic: What Makes a Good Minimal Shoe?

The research team concluded that the lack of artificial arches or mechanical support in the minimal shoes caused the intrinsic and extrinsic foot muscles to work and develop more. In other words, arch supports and cushioning from conventional shoes acted as a crutch that prevented foot muscles from working and strengthening. The minimal shoes, on the other hand, demanded more work, leading to more stabilizing muscles and strengthening of the foot/leg core system.

According to Dr. Roy Cheung Tsz-hei, who headed the study, runners in minimal shoes are less likely to suffer injuries because stronger foot muscles would lessen the impact on bones and tendons.


This isn't groundbreaking news to us—on the contrary, it's what we've heard for many years from experts in the field, including biomechanist Katy Bowman, MovNat founder Erwan le Corre, renowned running coach and author Phil Maffetone, paleo guru Mark Sisson and podiatrist (and Correct Toes inventor) Dr. Ray McClanahan. It is, however, the first time a major study has substantiated these claims on this scale.

We're not saying minimal shoes are for everybody. Even Born to Run author Chirstopher McDougal has always said there is no need to change to minimal footwear or barefoot running if you have no injuries or foot problems with your current footwear. If, however, you suffer from foot pain, knee pain or want a more natural, barefoot-like experience then we hope you'll consider the minimalist route before investing in expensive orthotics and heavily cushioned shoes. While that thick padding may ease your pain at first, this study suggests that such cushioning may only weaken your feet further in the long run.

One word of caution: if you decide to transition to minimalist shoes, don't rush into it! Most injures people develop from minimal footwear result from transitioning too quickly before properly adapting their feet. Check out our previous post for tips on a safe transition:

Tips for Transitioning Safely to Minimalist Shoes

Please note that we are shoemakers, not doctors, and cannot prescribe medical advice. Nothing we say is intended to replace the advice of your medical professional.

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  1. Sharon
    I don't need no stinkin study - my softstar shod feet are proof enough for me. but for my skeptical friends and relatives..can we get a link to the study?
  2. emily
    I had been running in zero drop running shoes for 4 years. No injuries. Recently decided to try some extra cushioning 4 mm drop (didn't sound like too much) Sauconys. Now 2 months later... I have tendonitis in one foot and can't run!
  3. Heather
    well, those Vibram 5 fingers are not really minimalist shoes. They are very confining and only work if you have "normal" feet. I once tried to fit a pair onto my feet and could have cried but laughed instead.
    Mainstream companies try come up with 'minimalist' footwear and running shoes but they will have some heel and toe spring, not flexible and are narrow. Even supposedly minimalist footwear companies can have very narrow sizing which is baffling. A healthy foot is fairly wide with spread out toes. My toes are nowhere near that, but soft star shoes have really been amazing for me. I cannot wear anything conventional. I love shoes and boots but can't wear them, so bit by bit my collection has been given to family and friends or sold on eBay! Biomechanically most shoes are a nightmare! I force my feet into rubber boots out of necessity but yuck.
    And of course you get stronger legs and feet with correct footwear! I have always walked a lot, biked, swam etc, but minimalist shoes make a huge difference and my too short achilles heels are actually finally stretching.
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