You walk into a sports shop to buy some running trainers and, five minutes later, you've heard about pronation, drop, carbon plates, responsive foam and “dynamic stability”. You walk out feeling like you need a lab to choose a pair of shoes.
You don't. Research in recent years has made this conversation much simpler, and the factor that matters most is one you already have: comfort. In this guide we explain what really counts, what's mostly marketing, when to change your pair and the part no shoe can fix.
What the science says: comfort comes first
For decades, the rule was this: you look at your gait, and if your foot “rolls inwards” (pronation), you buy a motion-control shoe. It seemed logical, and it's still how many shops sell them.
The problem is that when it was measured, the link did not show up. Reviews pooling several trials with thousands of runners found no convincing evidence that choosing shoes by foot type reduces injuries. It has not even been shown that pronation alone causes the injuries it is usually blamed for.
What research has pointed to is simpler: choose the pair that feels comfortable when you run in it. Researchers call it the “comfort filter”. Your body is better at feeling what suits it than a general rule made for everyone.
This doesn't mean a gait analysis is useless. It can help you see whether there's something to work on in your technique or strength. It just shouldn't be the only reason you pick one model over another.
Box words, explained
Even if comfort calls the shots, it's worth understanding what you're being sold. These are the features you'll find on almost every spec sheet.
| Feature | What it is | What it means for you |
|---|---|---|
| Drop | Height difference between heel and forefoot, in millimetres | A high drop (8 to 12 mm) is the most common. A low drop puts more work on the calf and the Achilles tendon: if you switch, do it gradually |
| Cushioning | Amount and type of foam in the sole | More foam is usually more comfortable over long distances and on tarmac. There's no evidence that, on its own, it prevents injuries |
| Stability | Reinforcements to limit foot movement | Useful if you feel more secure with it. Not mandatory if you overpronate |
| Weight | Grams per shoe | Lighter pairs are for fast paces and tend to last less |
| Carbon plate | Rigid plate inside the sole | Built for racing. For beginners, it's money badly spent |
| Trail sole | Deeper lugs and grippier rubber | For dirt, packed sand and trails. They wear out quickly on tarmac |
If you're a beginner, the shoe you need almost always has the same profile: an everyday training model, with moderate cushioning and a normal drop. It's the most versatile category and the most forgiving of mistakes.
How to choose in the shop, step by step
A good choice is made with your feet, not the catalogue. Take these steps with you.
- Go at the end of the day. Your feet swell over the day and they swell when you run too. A shoe that fits snugly at 10:00 can pinch halfway through a run.
- Bring the socks you run in. A thick or thin sock changes the fit more than you'd think.
- Measure both feet. It's normal for one to be slightly bigger. Buy for the bigger one.
- Leave room at the front. With the shoe on and laced, there should be roughly a finger's width between your big toe and the tip. On downhills your foot slides forwards, and that's where black toenails come from.
- Check the heel. Your heel shouldn't lift when you walk. If it does, the problem may be the model, not the size.
- Run, even if it's just in the shop aisle. Walking isn't enough. If you can, compare two or three models side by side, without looking at the price or the brand, and pick the one that feels most natural.
- Be wary of “it'll stretch”. A running shoe should be comfortable from day one. If it pinches in the shop, it'll pinch at kilometre five.
Where you'll run changes the choice
The question often missing in the shop is this one: where are you going to run?
If you mostly run on tarmac and pavement, like people who run the seafront between Buarcos and Figueira da Foz, a road shoe with moderate cushioning is the most sensible choice. If you run on dirt tracks, hill paths or dunes, a trail sole gives you more grip and better protects your feet from stones.
And if your running happens within a workout, that is, short blocks mixed with squats, jumps or lifts, then you're no longer looking for a pure running shoe. A very high, soft sole can give you little stability when you've got a barbell in your hands. For that case we've written two guides: which shoes to wear for CrossFit and when it makes sense to have two pairs.
How long do running shoes last?
The figure most used by manufacturers is between 500 and 800 kilometres for an everyday training model. Lightweight and racing models often fall below that.
It's a range, not an expiry date. People who weigh more, run more kilometres a week or run on uneven ground wear the foam out faster. People who run little and on even ground can go further.
Rather than counting kilometres, look out for these signs:
- the sole has smooth patches or is worn down to the foam;
- the foam in the sole has deep creases on the side;
- the shoe leans to one side when you put it on a table;
- you've started feeling new pain in your legs or feet without having changed your training;
- the pair feels “hard” and no longer gives you the comfort it used to.
Is it worth having two pairs?
If you run several times a week, it may be worth it. A study of amateur runners in Luxembourg, published in 2015, found that those who rotated between more than one pair of shoes had an injury risk about 39% lower. The most likely explanation is that varying the stimulus spreads the load across different structures. It's one study, not a law, but it's a good reason not to throw out your old pair the day you buy the new one, if it's still fit for short easy runs.
What no shoe will do for you
This is the part shops don't usually tell you: most running injuries have more to do with how much and how you train than with what's on your feet.
The most common causes are well known:
- Increasing volume too quickly. Going from two to five runs a week, or doubling your distance from one month to the next, is the fastest way to end up with knee or shin pain.
- Always running at the same pace. Mixing easy days with harder days gives your body time to adapt.
- Lack of strength. Strong legs, hips and core cope better with thousands of strides.
On that last point, the evidence is among the strongest there is. A meta-analysis published in 2014 in the British Journal of Sports Medicine, which pooled trials across several sports, concluded that strength training cut sports injuries to less than a third, and overuse injuries by almost half. No foam, however good, comes close to that.
In practice, this means two strength sessions a week, with simple, well-executed exercises: squats, deadlifts, lunges, calf and core work. Add some joint mobility work for your ankles and hips, and you have the best protection a runner can buy. If you're not sure how to fit all this into your week, our article on how many times a week to train will help.
Quick summary to take to the shop
- Choose based on comfort when running, not on your foot strike type.
- To start, an everyday training model, with moderate cushioning and a normal drop.
- Buy at the end of the day, wearing your own socks, and leave a finger's width of space at the front.
- Choose by the surface you run on: road, trail or mixed training.
- Change pairs between 500 and 800 km, or sooner if the sole and your body tell you to.
- Remember that strength protects you more than any shoe.
Run better with stronger legs
Many Revolution members started out as runners. They came because they wanted to stop being in pain, run faster or simply have more strength for life, and in the CrossFit classes they found the strength training their week was missing, with a coach correcting their technique and a group pushing them on.
If you run and have never done proper strength training, your first class at Revolution, in Buarcos, is free and needs no experience at all. Tell us you're a runner, and the session is adjusted to you. We have classes all day, from 06:30 to 21:00: see the timetable, check the plans on prices, with no small print, and book your class through contacts.
Bring your running shoes. We'll tell you if they work for today's session.
