Joybuy Insights

Choosing size 40 trainers: a practical guide to comfort, style and use

When you search online for size 40 trainers, you’ll quickly find dozens of styles for men and women. However, the same EU size doesn’t tell you everything. A running shoe may fit differently from a casual trainer, while a leather style will have less give than one with a mesh upper. Popular terms such as “extra comfort”, “performance fit” and “sustainable” are only useful when you know which product specifications they refer to.

This guide will help you compare men’s size 40 trainers, women’s size 40 trainers, running shoes and styles for everyday wear objectively.

Three common trainer-buying mistakes

1. Relying on EU size alone

EU size 40 is a good starting point, but the foot length associated with that size can vary between brands and styles. For example, the product information for the adidas Supernova Stride 2 gives a foot length of 250 mm for size 40. The adidas Adizero Boston 13 lists approximately 256 mm for size 40. You may notice this difference on longer walks or runs.

So always check:

  • the size chart for the specific style;
  • the stated foot length in millimetres or centimetres;
  • whether the style is intended for men, women or both;
  • whether you have enough room around your toes.

2. Wearing casual trainers for intense training

A flat sole and sturdy rubber outsole can be comfortable for walking, everyday wear or skateboarding. That doesn’t automatically mean the style is suitable for running. Size 40 running shoes usually have different features, such as a mesh upper, cushioned midsole and construction designed for repeated movement.

Vans Old Skool, Vans Authentic and Converse PL Vulc Pro OX styles are better suited to casual wear or light skating. For running training, styles such as the adidas Runfalcon 5, Supernova Stride 2 or Adizero Boston 13 are more relevant to compare.

3. Underestimating materials and care

Leather, suede, canvas, synthetic materials and mesh all respond differently to rain, dirt and everyday wear. Suede can give your trainers a smart look, but it needs a suitable brush and protector. Mesh is generally breathable, but can be harder to clean in specific areas.

Check the care instructions. Many styles in this selection are not machine washable. Manufacturers usually recommend wiping them with a damp cloth and allowing them to dry naturally, away from direct heat.

Important specifications for size 40 trainers

Foot length and fit

Measure both feet at the end of the day, wearing the socks you’d normally use. Note the length of your longer foot and compare it with the size chart. For sports styles, make sure you have enough room around your toes; a fit that’s too tight can become uncomfortable when you’re moving.

Laces help you adjust the fit. According to the product description, the adidas Supernova Rise M ATR has an adjustable lacing system and a padded insole. These are features you can check, but overall comfort still depends on the shape of your foot.

Midsole and cushioning

A soft insole or midsole can feel comfortable for everyday walking. For running, it’s worth looking at the specific construction. The adidas Runfalcon 5 lists a Cloudfoam midsole and OrthoLite insole. According to the product information, the Supernova Stride 2 uses a Dreamstrike+ and EVA midsole.

These terms describe the components used; they don’t guarantee that a shoe will be equally comfortable for everyone. If you mainly do speed or intensive running training, you could compare the adidas Adizero Boston 13. This style lists Lightstrike Pro, ENERGYRODS and a Lighttraxion outsole with Continental Rubber.

Upper, sole and grip

Mesh and textiles are worth considering if you want a lighter feel. Leather, suede or synthetic leather are often easier to style for streetwear. A rubber outsole can provide grip, but the tread and the surface you’re walking on also matter.

  • Size 40 casual trainers: consider the material, weight, walking comfort and care requirements.
  • Size 40 skate shoes: look for a sturdy sole, good grip and protection around your foot.
  • Black size 40 trainers: practical for everyday wear and less likely to show visible discolouration.
  • White size 40 trainers: easy to style, but marks show up more quickly.
  • adidas size 40 trainers, Vans size 40 trainers and Converse size 40 trainers: always compare the size chart for the specific style, rather than relying on the brand alone.

Recommended styles for different types of wearer

Suitable for: Beginners on a budget
Adidas Runfalcon 5 size 40

Adidas Runfalcon 5 GRESIX/CBLACK/FTWWHT IE8819 40

Why it suits this type of wearer: This style is designed for everyday training, treadmill use and an active routine. Its mesh upper and Cloudfoam midsole make it a practical choice if you’re looking for one pair of sports trainers.

How this style avoids the pitfall

The product information names specific materials and components, rather than relying on vague claims about comfort. Be sure to check the size chart before ordering.

Key benefit & features

Mesh upper, Cloudfoam midsole, OrthoLite insole and Adiwear outsole, according to the product description.

Suitable for: Shoppers looking for premium quality
Nike Dunk Low size 40

Nike Wmns Dunk Low HM9655-001 40

Why it suits this type of wearer: This women’s style is made for fans of a recognisable streetwear design with a low profile. The black-and-white colourway is easy to pair with everyday outfits.

How this style avoids the pitfall

The product description specifies a leather upper, padded collar and rubber outsole. It isn’t a running shoe, so it’s best suited to casual wear.

Key benefit & features

Leather upper, padded collar, cushioned insole and rubber sole with a pivot circle, according to the product information.

Suitable for: Specific activities & intensive use
Adidas Adizero Boston 13 size 40

Adidas Adizero Boston 13 M CBLACK/CARBON/CBLACK JS4941 40

Why it suits this type of wearer: According to the product information, this style is designed for intensive training sessions and race preparation. It’s therefore better suited to runners than to someone looking for everyday trainers.

How this style avoids the pitfall

Its intended use and construction are clearly described. Before buying, check that the running style, surface and fit are right for how you plan to use it.

Key benefit & features

Lightstrike Pro midsole, ENERGYRODS, breathable textile and a Lighttraxion outsole with Continental Rubber, according to adidas.

Other styles to compare

For a retro everyday style, take a look at the New Balance 574 size 40. According to the product information, it combines a suede upper, mesh lining, rubber outsole and padded midsole.

If you’re after a skate-inspired look, compare the Vans Hylane VN000D1JBRO1 Brown 40 or a Vans Old Skool. The Hylane has a suede and synthetic upper, cushioned insole and rubber treaded sole. For a simpler black style, the Vans Authentic VN000EE3BLK1 is an option with a textile upper and rubber outsole.

The Converse PL VULC PRO OX size 40 has a low profile, suede upper and vulcanised rubber sole. This makes it an interesting option for everyday wear and light skating, but not necessarily for long running sessions.

Looking for more options?

We’ve put together a complete, up-to-date list of products that meet these strict selection criteria and current European safety regulations.

Frequently asked questions about size 40 trainers

Is size 40 the same for every brand?

No. The fit and stated foot length can vary between brands and styles. So compare the size chart for the style you’ve chosen, and also check the width, toe room and shape of the shoe.

How long do size 40 trainers last?

Their lifespan depends on use, the surface you wear them on, body weight, care and materials. A pair worn every day will wear differently from one you rotate with other shoes. Where possible, alternate between pairs and let any moisture evaporate naturally after wearing them.

Can I use ordinary trainers for running?

They may be comfortable for short walks or light activities, but ordinary casual trainers aren’t specifically designed for repeated running impact. If you run regularly, choose a style whose product information states that it’s intended for running or training, such as a Runfalcon, Supernova or Adizero style.