Running shoes soles explained

October 16 2018

Now that summer has been and gone, that all too familiar British weather is right around the corner. The colder months means that it’s the perfect time to take a look at an important, yet often overlooked, part of your running kit — the soles of your shoes.

Much like the tread on your car’s tyres, each pattern on a sole of a running shoe is designed for a specific purpose. After all, you wouldn’t drive a hatchback in a muddy field. Likewise, super-grippy shoes won’t do you much good when you’re running through the city streets.

Running shoe grip explained

There are two main sources of grip: friction and traction.

Friction comes from how much contact area a shoe has, and is great for running on roads or rocky terrain. Shallow lugs have more contact area with the ground, which makes them more suited to these surfaces. If you’re running on softer ground, then you’ll want to choose deeper lugs. Their tapered ends have less surface contact, but dig deep into grass and mud to give you greater traction.

Lug depth

You should make sure the lug-depth of your shoes is best suited to you and your running style. Boggy runs suit about 8.5mm lugs, while 3.5mm lugs are better for the traditional road and park runs that most of us enjoy. If you like to mix it up, choosing lugs of around 6mm offer a bit of contact area combined with the ability to dig in if you need.

Material

A softer rubber on the outsole of your shoes will tend to have better traction on damper surfaces, but be less durable than its harder equivalents. Most of us tend to face a mixture of surfaces though, so a sole with very soft rubber will wear down quite quickly.

Pattern

Lugs will lose their effectiveness if the outsole gets caked in mud. Wide spacing between the lugs means less mud and fewer stones will be picked up. This will also help prevent you from carrying too much extra weight.

Lug direction 

The direction of the lugging is important if you’re a hill runner. In the forefoot of some shoes, the lugs face backwards, whereas in the heel all the lugs dig in and face forwards. When you run uphill the lug direction means they will be able to pull back against the hill so you can push yourself up. While on the downhill, the different direction helps you brake. 

The Road-to-trail

Lugs

Shallower grooves are best for running on Tarmac and more uneven ground 

Pattern

Having plenty of teeth on a shoe helps ensure a wider contact area

The all-rounder

Lugs

6mm of depth is a middle ground for trail shoes, giving you the best of both worlds

Pattern

Packed lugging will leave you comfortable on less tricky trails 

The rocky trail

Outsole

More durable material is needed on rocky terrain than for muddy ground

Pattern

Multi-directional lugs can provide added traction, especially on hills 

The one for mud

Lugs

Deeper teeth mean the shoes can dig further into mud to find some firmer ground

Spacing

Big gaps between lugs help stop stones and mud from being collected

Whether it’s a rocky trail or the running track, research your route to find out which shoes are right for you. When you’ve decided on your style, take a look at our full range of men and women’s trainers.

Once you’ve picked out your perfect pair, take a look at our 9 top tips for upping your running game.

Visit the England Athletics website for more help and advice on running and keeping fit.