Why Our Feet Sweat – And Why Good Footwear Matters
How the foot’s natural moisture release affects the climate inside your shoes – and the role materials, fit, and footbeds play in keeping it balanced.
Sweaty feet are something we all know – because foot moisture affects not only comfort and the way a shoe feels, but also your health and even athletic performance. Especially under intense physical strain, foot sweat can become a real problem – leading to slipping inside the shoe or even painful blisters.
What many people don’t know: the feet are among the most active sweat zones in the human body. In this article, we explain why – and how the choice of materials, fit, and manufacturing quality in footwear can make a real difference.
The Sweat Glands of the Feet
The skin is the largest organ in the human body – and it’s filled with millions of sweat glands. The hands and feet are especially densely populated. A simple test with latex gloves proves the point: as soon as the skin’s ability to breathe is restricted, the hands quickly become moist.
This effect is even more pronounced on the feet: the soles contain around 370 eccrine sweat glands per square centimeter – even more than the palms, which have about 360.
These glands serve a vital function: they release moisture to regulate body temperature. Sweat is more than 99% water – and its evaporation on the surface of the skin creates the desired cooling effect. At the same time, moisture improves grip on both hands and feet – for example, when gripping an object or walking barefoot on smooth surfaces.
The Amount of Moisture Our Feet Actually Release
Even under moderate conditions and average activity levels, the feet release a surprising amount of moisture: around 250 ml of sweat per day comes from the soles alone. That equals roughly 10.4 ml per hour – for both feet combined.
Over the course of an eight-hour day, that adds up to more than 40 ml per foot – which is more than two shot glasses. And during high physical activity, this number can increase significantly.
What This Has to Do With Footwear
Since our feet are often enclosed in shoes made from materials with limited breathability, they can overheat. To counteract this, the body boosts sweat production to regulate temperature.
The result: a humid climate inside the shoe – accompanied by discomfort, increased odor, and the risk of moisture buildup softening the skin. Especially during sports or long-distance runs, this can lead to friction and blisters.
Why Materials and Fit Are So Important
When buying shoes, it’s essential to ensure that the feet have enough room and that the materials used are both high quality and breathable. Feet need to breathe – and that’s not just a figure of speech.
Unfortunately, the reality often looks quite different: many shoe manufacturers choose less breathable materials for cost reasons. In addition, fashion-driven design choices – such as pointed toe shapes – often leave the feet with too little space.
Genuine leather is often praised as a cure-all for sweaty feet and a healthy shoe climate. But this only applies to high-quality, untreated leather – because not all leather is created equal. Many shoes use inexpensive leather sourced from low-wage countries, often processed under questionable conditions. These materials may contain harmful chemical residues that can be absorbed through the skin. And they don’t just affect the wearer – but also the people involved in the production process, and ultimately the environment.
The same concerns apply to shoes made from synthetic materials. Here, too, manufacturers often rely on low-cost, inferior components that may be contaminated with substances harmful to skin and health.
A Better Shoe Climate Starts With Responsible Materials
Fortunately, there are alternatives: vegetable-tanned, toxin-tested leathers produced sustainably in Europe – ideally under strict regulations in Germany. These leathers come from responsible production, with untreated, open-pore surfaces that allow the foot to breathe and absorb moisture naturally.
One of the most rigorous certifications in this area is the IVN seal issued by the International Association of Natural Textile Industry (IVN). It evaluates not only the product but the entire supply chain – from animal welfare and tanning to wastewater management.
That’s why we use only vegetable-tanned, toxin-tested lining leathers certified by IVN – in all bespoke Vitallo shoes as well as the leather-lined ready-to-wear models from VitalloFlex.
There are also safe, skin-friendly alternatives among modern functional fabrics and synthetics. This is especially important for performance shoes, where feet are under high stress and particularly sensitive to material properties.
That’s why we follow the same principle in our textile linings for all Runnertune and VitalloFlex sport models – all of which are fully certified according to the strict Oeko-Tex Standard.
You can learn more about the materials we use here.
The Footbed – A Key Factor in Shoe Climate
As mentioned earlier, the sole of the foot is one of the most active sweat zones of the body – with the highest density of sweat glands anywhere. That places special demands on the interior of a shoe – especially the footbed.
Many common solutions – from simple insoles to foam-based inserts – are unable to absorb moisture effectively.
Typically, these footbeds consist of:
- Upper material (e.g., leather or textile)
- Adhesive layer as a bonding agent
- Footbed base (usually made of soft foam)
The problem: the adhesive layer acts as a moisture barrier. It prevents sweat from reaching the base layer. And even if it did, most conventional plastic foams aren’t able to absorb moisture in the first place.
Climatocork – For Greater Comfort
That’s why we developed Climatocork: a unique footbed system based on cork – a renewable raw material – combined with a breathable top layer made from either vegetable-tanned leather or skin-friendly performance textile.
To allow moisture to pass freely into the cork, the top layer is not bonded to the footbed base. This is made possible by a specialized manufacturing process developed in-house. This creates a skin-friendly, comfortable climate inside the shoe.
The benefits at a glance:
- High moisture absorption thanks to unbonded, breathable top layers
- Natural cushioning without synthetic foams
- Thermoregulating effect – ideal in heat and cold
- Skin-friendly, toxin-tested materials
Learn more about the development and function of our Climatocork footbed – and why cork is the ideal material for it – in this Journal article.
Responsibility for Health and the Environment
In the end, it’s simple: conscious choices lead to more comfort, better health, and greater well-being – while also supporting responsible practices for people and the planet.
For us, a healthy shoe climate is no coincidence. It’s the result of premium materials, intelligent design, and innovative production methods.