My old pair of Salomon XA Pro 3D Ultra GTX Trail Running Shoes were incredible. They were waterproof, comfortable, and quite stylish (to an urban hiker like me). I wore those puppies into the ground. So when it came time to replace them, I decided to avoid the shops and order a fresh pair of this year’s model online.

The shoes haven’t changed much, except for one thing: the size! Seems the new model runs a bit bigger, and I’m feeling a little less certain about my purchasing decision. This has prompted me to spend (waste?) countless minutes (hours?) obsessively pouring over articles about shoes.

For active people like us, having the right shoe is paramount to avoiding injury. This is especially true for runners who put a lot of stress on their feet as they pound away the miles on the hard pavement.

Whether you’re a runner, walker or hiker, the specific shoe you get will depend on your purpose, but here are a things I’ve learned while inhaling the internet:

How much wiggle room?

There should be adequate “wiggle” room between the end of your longest toe and the front of the shoe. If you don’t have about a half-inch between your longest toe and the end of the shoe — approximately the width of your finger — try a larger size.

How much heel room?

For a good fit and good stability, your ankle should fit snugly inside the heel cup of the shoe with minimal slippage.

Do this heel check: With your feet in the shoe, it should be difficult for you to slip your thumb between your heel and the back of the shoe. If you can, your shoe may slip causing nasty blisters on the back of your heel.

Feel inside the heel for a hard material. That is the heel counter. That counter should fit just right to your heel, but not press against your ankle bone. If it does, over time you may get a blister on your ankle.

How wide?

Mayoclinic says that the side-to-side fit of the shoe should be “snug but not tight”. So what’s the difference between “snug” and “tight”?

CoolRunning says:

Trying on a shoe, you should feel like your foot is evenly distributed inside the shoe and is not left hanging over the side of the midsole Tie the laces the way you normally do.

If you have a narrow foot, check that the material at the base of throat of the shoes where the laces start does not bunch up.

What about arches and pronation?

Pronation describes the normal motion of the foot rolling slightly inward through the foot strike. Pronation is essential to shock absorption and forward propulsion. It’s when you overpronate or underpronate (supinate) that you need to be particular about your shoes.

Whether you pronate depends on your arch type. The three basic arch types – normal, flat and high – correspond to a degree of pronation.

What is my arch type?

To determine your arch type and pronation, you can do a simple “wet test” with a bit of water and a paper towel.

Dip your foot in water and step on a piece of paper towel or cardboard. Examine your footprint and compare it with the arch types above. If you can see most of your footprint, you probably have low arches. If you see very little of your footprint, you likely have high arches.

Sierra Trading Post also suggests you look at your shoes:

Another way to determine arch type is to look at the outsoles of your old running shoes, although this method is less reliable than the Wet Foot Test. If the sole is worn equally on both sides, you most likely have a normal arch. If you have a flat arch, the sole will show excessive wear on the inside. A high arch usually produces a sole with noticeable wear on the outside.

Quick Tip: You cannot determine arch type by looking at the wear pattern on the heel alone, although this is a common misconception.

Which shoe for which arch type?

Your arch type determines your shoe type.

Normal Arches

Stability shoes have light support features on the medial side and well-cushioned midsoles to help guide mild-to-moderate overpronation. Runners with a normal arch can also benefit from light stability features.

Flat Arches / Overpronation

Motion Control shoes incorporate extra stability features on the medial side to help control severe overpronation. Runners with a severely flat arch are well suited for these types of shoes.

High Arch / Underpronation

Cushion shoes are the most flexible and encourage pronation. They incorporate extra cushioning and shock absorption, and do not have stability or motion control features.

General Tips

• Fit your shoes to the largest foot.
• Try on shoes at the end of the day (or after a workout for athletic shoes) when your feet are the largest.
• Try shoes on with the same thickness of socks you intend to wear.
• If you use orthotics, try the shoes on with them.
• Your heel should fit comfortably with a minimum of slippage.
• Your shoes should be snug but NOT TIGHT.

Extra lessons

I eventually caved in and reordered my shoes a half size smaller. Now I’m left with a slightly used (and slightly expensive) pair of shoes that I can’t return. There are two things I’ve learned from this:

Suck it up and go to the shop. No matter how much you hate shopping, it’s worth going to the store to try on a few different types and sizes of shoe. And if you’re lucky, the salesperson will know their stuff and be able to help you determine your arches and the best shoe for your feet.

Don’t wear shoes outside unless you’re 100% sure that you want to keep them. If you have the slightest doubt, wear them in the house for a few days and if you’re still not sure return them and try something else.

And if you still can’t decide

Two words: Go Bare.

Shoe Resources Galore

• Walking shoes: Features and fit that keep you moving [Mayoclinic]
• A Running shoe guide for Dummies [Cool Running]
• 10 Tips for a Good Shoe Fit! [MedicineNet]
• How to Choose Running Shoes [REI]
• What shoe? [Ransacker]
• Running Shoe Guide [Sierra Trading Post]

And if you’re in the market for a pair of US size 8 trail running shoes, give me a shout!