Running in barefoot shoes: What really happens to your body?

Wondering what happens to your body when you lace up barefoot shoes? Physiotherapist Michael Tichov from FyzioGO takes a look at what science says about running in barefoot shoes.

Thinking about switching to barefoot shoes, but not sure what to make of it? You’re not alone — enthusiastic runners on one side, sceptical orthopaedic specialists on the other, and a pile of half-truths on social media. Some say running “barefoot” is a return to what’s natural. Others warn it’s the quickest route to injury.

Physiotherapist Michael Tichov from FyzioGO puts it plainly: over the last fifteen years, science has done a huge amount of work on this topic, and it gives us fairly clear answers to most questions. Researchers have tracked how foot strike changes, how joints are loaded, how the foot muscles work, what the injury risks are, and how running efficiency shifts. And the conclusion? Barefoot shoes are definitely not a miracle fix that solves everything for you — but at the same time, it’s hard to ignore that the findings are consistent, and runners who manage the transition with good technique and gradually do genuinely benefit. So let’s look at what we actually know.

How does running mechanics change?

Running in barefoot footwear isn’t just about the shoes. It’s mainly a different way of loading your feet — and, by extension, your whole body. When you take a runner who’s spent years in cushioned shoes and put them on a thin sole, their technique almost always changes. And science describes exactly how.

1) Foot strike shifts from heel to midfoot or forefoot

In conventional running shoes, around 75–90% of runners land on their heel. It’s natural — the thick cushioning under the heel allows it and, in a way, encourages it. But once that cushioning is significantly reduced, heel striking suddenly feels uncomfortable, and within a few steps your body will ask for a change.

Barefoot runners naturally move towards a midfoot or forefoot strike. And that has a major impact on what happens in your body with every step. Changing your foot strike doesn’t remove impact forces, but it significantly changes how they build up:

the rate at which impact enters the body drops markedly — the more slowly the impact travels through the body, the less it stresses it
load shifts more towards the calf muscles and the Achilles tendon
the knee is loaded less, but the foot and ankle do more work

That reduction in impact loading rate is one of the most important factors in preventing running-related pain — especially shin and knee pain, which are exposed to lower forces in barefoot running.

2) The muscles of the foot switch on

Barefoot shoes don’t guide the foot, support it, or otherwise “help” it. That may be their biggest advantage — your foot simply has to do the work itself. Measurements of muscle activity confirm this, showing:

greater activation of the small muscles of the arch
a better ability of the foot to absorb impact thanks to its own stabilisation
overall strengthening of the foot in regular users of minimalist footwear

This is why some physiotherapists see barefoot shoes as a training tool. The foot simply has to work. And that brings us back to the well-worn saying: “barefoot shoes are a gym for your feet”.

3) Strides get shorter, cadence gets higher

The last change may not be as obvious — but it has a big influence on your overall movement. Switching to barefoot naturally shortens your stride length and increases your steps per minute. This brings:

lower braking forces with each landing (when the foot lands, using the foot leads to a smoother distribution of forces and avoids a hard impact that travels up into the upper body)
smoother movement
often less energy loss on landing.

So the changes in running mechanics triggered by barefoot shoes are real and well described. But what happens next — inside your body? A different foot strike and a different step rhythm directly affect what’s happening in your muscles, tendons and bones in every training session. And that’s where it’s decided whether barefoot running helps you — or harms you.

What happens to muscles, tendons and the arch?

When you start running in barefoot shoes, it’s not just your foot strike that changes. The biggest transformation happens deeper — in the structure of the foot itself, the arch, and the calf complex. Science already has a fairly good idea of what’s going on there.

1) Knees get a break and the ankle becomes more stable

One of the most commonly mentioned benefits of barefoot running is relief around the knees. That’s no coincidence — by changing your foot strike, most of the load is redirected into the foot and calf, which naturally reduces load on the knee and hip joint. That’s why many runners who have battled knee pain for years feel noticeable relief after switching to barefoot shoes.

Interestingly, even though greater forces pass through the ankle in barefoot running than in a conventional shoe, the entire lower limb is paradoxically more stable. The ankle deviates less side-to-side, moves in a more solid line, and load is transferred more effectively into the calf muscles. The result is better overall stability of the lower limb.

2) The small muscles of the arch get stronger

Barefoot shoes don’t support the arch — so all the muscles in the foot have to do their job fully. Research shows:

greater activation of foot muscles when running and walking in barefoot shoes
increases in muscle strength and size after regular use
better arch stability and less tendency for it to “collapse”

A 2014 study even demonstrated a measurable change in arch height after just six weeks of training in barefoot shoes — precisely because the muscles that support the arch became stronger.

3) The Achilles tendon and calves work much harder

A midfoot or forefoot strike shifts significantly more load into the calf muscles and the Achilles tendon.

This comes with both positives and risks:

better elasticity while running (your body learns to absorb impact better and foot strike and roll-through become smoother)
the tendon system gradually strengthens
tendons become more elastic and work better like a “spring”
with a rapid transition, the Achilles tendon almost always complains
there’s a risk of overload or soreness where the tendon meets the heel

Calf muscle soreness often appears — that’s normal, but you can’t overdo it. It’s like typical muscle soreness after a gym session. Your body simply needs time to adapt.

4) The arch starts working better

The arch of the foot works like a natural spring. In barefoot footwear it has to work more, because the cushioning isn’t taken over by a thick, shock-absorbing sole.

Study results show:

improved ability of the arch to “work” on landing,
better control of pronation (the natural inward roll of the foot that helps absorb impact and adapt to the ground)
strengthening of the plantar fascia (ligaments and connective tissues on the underside of the foot).

But watch out for one thing — ligaments and tissues adapt more slowly than muscles. A 2017 study confirms that barefoot shoes have a positive effect on the arch — but only in people who transition gradually and slowly.

5) Structural changes in bones

Overloading the small bones in the forefoot is the best-known risk of switching to barefoot too quickly. A 2013 study described that in runners who transitioned too fast, early signs of stress reactions appeared in these bones — without an actual injury occurring. The problem wasn’t barefoot shoes themselves, but the speed of the transition.

Bones adapt more slowly than muscles, which is exactly why gradual progression matters so much. The good news is that patience pays off — bones that gradually get used to the new load can increase their density over time and become significantly more resilient than before.

6) Your feet start sensing the ground better

Heavily cushioned shoes smooth out a lot — impacts, instability, uneven ground. But at the same time, they take something important away from your feet: information about the surface you’re running on. Barefoot footwear changes that.

This leads to:

better perception of the surface and terrain
faster corrections with each landing
better ankle stability
reduced risk of sprains in more experienced barefoot runners

This effect is often underestimated in discussions about barefoot shoes — yet it’s one of the biggest benefits, not only for running but also for everyday walking.

How to transition to barefoot running gradually

All the changes described above have one thing in common: they take time. Here are a few tips to help you manage the transition without unnecessary aches and pains.

Start slowly. Don’t begin by wearing barefoot shoes for your usual training run. For the first few weeks, use barefoot as an add-on — a walk or an easy jog in the park. Your body needs weeks, not days, to adapt.

Choose the right shoes. The key parameters are zero drop, a sufficiently wide toe box, and a thin but functional sole. Most importantly, the shoes must fit brilliantly. Beginners may benefit from shoes with a slightly thicker sole or a removable insole — it makes the transition more gradual.

Listen to your body. Mild fatigue in the calves or feet is normal. Sharp or long-lasting pain in the Achilles, the forefoot, or elsewhere is a signal to slow down. The difference between healthy adaptation and overload is usually how quickly you increased your volume.

Look after your feet. A great helper is a massage ball— regularly rolling your foot over the ball releases tension in muscles and tissues. Just a few minutes a day is enough, for example in the morning after getting up or in the evening before bed.

To sum it up — switching to barefoot is a bit like learning to run again. Not because you’ve forgotten how, but because your body has to rewrite movement patterns it’s built over years. A different foot strike, different joint loading, muscles working differently, a different step rhythm. Together, it creates a completely new style of movement. And like any new skill — it takes time, repetition and gradual progression. If you respect that, there’s a good chance barefoot running will bring the benefits you’re looking for: stronger foot and arch muscles, less load on the knees, better ankle stability, and overall more natural movement.

Article author: Mgr. Michael Tichov

An active sportsperson and physiotherapist who lives by the motto “a healthy mind in a healthy body”. His focus is on physical exercise, whether that’s sports training or therapeutic exercise aimed at helping people get rid of chronic pain. You can find more physio tips on the FyzioGo Instagram.

The article is based on findings from the following studies: Lieberman et al. (2010) — foot strike kinematics and reduced impacts; Daoud (2012) — injury incidence across different strike patterns; Bonacci et al. (2013) — movement pattern changes during transition; Ridge et al. (2013) — risk of bone overload; Miller et al. (2014) — changes in arch height; Roper et al. (2016) — metabolic load on the calves; Hollander et al. (2017) — long-term effects of minimalist footwear on the foot arch.