One number is hard to ignore. In a 2021 study, people who spent six months doing everyday activity in minimal footwear increased their foot strength by an average of 57 percent.
Most barefoot-running advice is about form, shoes, and injury. Far fewer pieces mention the one change researchers can actually put a number on.
Your foot muscles get stronger, and the effect is bigger than most people expect. Here’s what changes, by how much, and what it takes.
The muscles most shoes let you forget
Your foot has its own set of small muscles, and cushioned shoes do a lot of their work. They absorb force and control motion, so the intrinsic foot muscles end up contributing less than they’re built to.
These muscles matter more than their size suggests. The abductor hallucis, the flexor digitorum brevis, and others help stiffen and spring the arch on every step, as the team behind the 2021 Scientific Reports study describe.
When they’re weak, more of that load falls on passive tissue like the plantar fascia. That is one reason foot strength keeps turning up in research on running injuries.
Take the support away, even part of the time, and the muscles start working again.
What the numbers actually show
A 2022 review of nine controlled studies put rough figures on it. Foot muscle size rose by about 7 to 11 percent, and strength climbed anywhere from 9 to 57 percent, once people spent time in minimalist shoes or barefoot.
The 2021 study sits right at the top of that range:
- Foot strength rose about 57 percent on average after six months of daily minimal-footwear activity.
- People who had used minimal footwear for years tested about as strong, so six months seems to reach most of the benefit.
- The change was measured with instruments, not reported as a feeling.
To put 57 percent in context, that’s the kind of gain you might expect from months of targeted strength work. Here it came mostly from changing what was on people’s feet.
Barefoot or minimalist for foot strength
Minimalist shoes and fully barefoot are points on one path, not rival camps.
Both build strength. The studies that measured these gains used minimalist shoes, barefoot time, or both, and every one of them beat staying in cushioned shoes.
Minimalist shoes are usually the easier on-ramp. They hand your feet most of the work while still covering the sole, which matters on pavement and in the cold.
Fully barefoot asks a bit more, a bit faster, on safe surfaces. It also tests skin and tissue that haven’t been challenged in years. The choice between barefoot and minimalist is less about which is better and more about how much load you can handle now.
You may not need a separate routine
Here’s the practical surprise. A 2019 study found that simply walking in minimalist shoes built foot muscle about as well as doing dedicated foot-strengthening exercises, according to the Brigham Young University researchers.
Both groups gained size and strength over eight weeks.
The group in regular shoes didn’t.
The walkers weren’t handed a workout, either. They just spent more of the day in the minimalist shoes, which is the appeal for most people: it folds into something you already do.
That said, shoes are a tool, not a treatment. If you have foot pain or something like plantar fasciitis, that’s a conversation for a physical therapist, not a shoe swap. This is general information, not medical advice.
Strength comes with a speed limit
The same muscles that get stronger can also get overloaded.
Tissue adapts on its own schedule, and that schedule is slower than your motivation. Bone is the slowest of all.
In one 2013 study, runners who switched to minimalist shoes over 10 weeks showed more bone-marrow swelling in their feet than those who didn’t, a sign the load had outrun the adaptation. There’s more on that evidence in our look at what the research says about minimalist shoes.
The benefit is real. It’s just a reward for patience:
- Add minimalist time in small doses, starting with walking rather than running.
- Keep early runs short, and let soreness settle between them. Our transition guide lays out a slower ramp.
- Treat sharp or joint-deep pain as a stop sign, the way you would with any running injury.
Conclusion
The clearest benefit of barefoot and minimalist running isn’t speed or perfect form. It’s stronger feet, and the research can put a number on it.
You don’t have to run a step to start. Walking in less supportive shoes is enough to begin building the muscles.
Just let your feet set the pace of the change, not your enthusiasm. Stronger feet are earned over months, and once they’re there, they tend to stay.