By Brian Metzler

1. Make sure the shoe fits your foot

How a shoe fits your foot is still the most important element of choosing what to put on your feet. The key is finding a shoe that fits the shape of your foot – the length, the shape and the volume – and the best way to do that is to try on several pairs at a specialty running store before you buy. “If you don’t have a good fit, you don’t have anything,” says Kris Hartner, owner of Naperville Running Company in suburban Chicago. “It’s an individual process because every shoe brand and model will fit slightly differently. The best way to find out what works is to try on several models.”

Generally speaking, you’ll want the fit to be snug in the heel and midfoot or arch area, but otherwise it should fit or adapt to the specific size and shape of your feet. If you have a wide foot or narrow ankle, you’ll quickly learn that different brands of shoes have slightly different interior shapes and volumes. One of the new characteristics to emerge over the last several years is the idea of a roomier toe box. Having that extra room not only gives your toes a bit more wiggle room, but it allows your transverse arch in your forefoot to flex properly, allows your big toe to remain straight and un-compromised, and provides room for the other toes to splay out naturally, both of which contribute to your performance (i.e., better control and agility, more power, and greater range of motion) and the long-term health of your feet.

2. How much cushioning is enough?

How much cushioning do you need in a shoe? That’s been a hotly debated topic in recent years, especially as max cushioning shoes have become such a popular trend. Studies have shown that running in shoes with less cushioning can provide more stability and reduce injuries, and yet there is plenty of reason to believe that shoes with more cushioning tend to feel better on your feet over the long haul. Still, it’s a very personal question and one only you can really answer. Part of it comes down to personal preference, but part of it is based on performance aspects, too. The lower your feet are to the ground, the more you can engage a proprioceptive sense of how your feet need to move over various aspects of terrain – for example, getting precise footing while cornering or running at a fast pace on a road or track or running over a rocky section of trail.

Does that mean sacrificing comfort and some protection for nimbleness and agility? Yes, it might. On the contrary, if you’re wearing a highly cushioned shoe, you’ll have more protection and comfort but the proprioceptive connection with the ground will be a bit more vague. Also, while speed is most efficiently derived from slightly firmer shoes or cushioned shoes with firm plates, it doesn’t entirely mean that softer cushioning means you’ll run slower because so many new midsole foams are more responsive with high energy-return characteristics.

3. Do you need support?

For decades, excessive pronation was a four-letter word in the running industry. The natural but sometimes extreme inward-rolling of a runner’s ankle and foot upon impact with the ground was believed to be the cause of numerous injuries and therefore shoe designers and running stores took it upon themselves to try to slow it down or stop it with slightly supportive stability shoes or more restrictive motion control shoes. While excessive pronation certainly contributes to many common overuse injuries, it’s not the only factor, and trying to reduce or eliminate it with running shoes tends to only cause more challenges. Supportive running shoes are generally heavier and more constrictive and also work counter to a runner’s natural and preferred path of movement. Limiting that natural movement can actually increase the negative effects of impact forces.

The modern approach to building shoes is to allow the body to run the way it prefers. The best shoes for you will let you run as efficiently as possible with the least muscular effort. To some extent, that means shoes that allow the foot to move as there was no shoe, but with just enough of the necessary cushioning and protection. So instead of impeding the natural motion of the foot, ankle, and lower leg, shoes should embrace that motion or allow that movement to naturally transition through the gait cycle.

4. What is a shoe’s heel-toe offset and why does it matter?

Shoes with a lower heel are another modern approach to running shoes spurred by the recent storm of change. For years, running shoes were built with a steep forward-leaning ramp angle, meaning the bottom of the heel is significantly higher than the bottom of the forefoot. Typically, that offset – often called “heel-toe drop” – has been in the 10mm to 12mm range. But to better mimic a foot’s natural movements in the spatial environment of running, shoe brands developed models with much lower heel-toe offsets. Essentially, a lower heel-toe offset (and thus, a considerably less chunky heel component) will help reduce the need to overstride and run with a heavy heel-striking gait. While some shoe brands claim lower ramp angles (or zero-drop shoe geometry) can reduce injuries, that hasn’t really been proven or disproven. However, many people believe that a lower heel-toe offset—in the 4mm to 6mm range—can contribute to improved running form and reduce overstriding. You should definitely ask about the heel-toe offset of specific shoes while you’re at a running store or dig for the information online. If you decide to transition to lower heel-toe offsets, do it slowly.

“You don’t have to go all the way down to zero, but running in shoes with a slightly lower ramp angle will help you keep your foot strikes closer to your body,” says Jay Dicharry, a Bend, Oregon, physical therapist, noted running form guru and author of “Anatomy for Runners” and “Running Rewired.” “Ultimately, running in lighter shoes that have a lower heel will help you run with better mechanics.”

For example, Dicharry says, if you’ve been running in shoes with a 10-12mm drop, consider gradually going down to the 4mm to 8mm range when you buy your next pair of shoes. Some runners will be able to eventually transition down to the 0 to 4 mm range, but doing so too quickly – in other words, buying shoes with a lower drop and running a lot of miles or fast workouts – can lead to soreness, strains, and injuries to your feet, calf muscles, and Achilles tendons.

5. Flexibility vs. Rigidity

Generally speaking, the more flexible a shoe is, the more your foot will be able to move naturally with its preferred movement path over any type of terrain. When you run barefoot on soft surfaces, your feet don’t have to make adjustments for the variables of a shoe (i.e., the added weight, the cushioning, the structure, etc.). In other words, if the shoe isn’t impeding the natural movements of your foot, your brain can focus on balancing and propelling your body as you move through the terrain. But let’s face it, whether you’re running down a city street or running on a dirt path, you wear shoes for protection under your feet and at least a little bit of cushioning to soften the ride. With a flexible shoe that allows good range of motion, you’ll have maximum control and agility both in your typical running gait and amid the precise and unique movements necessary to conquer trail terrain, corner at faster paces on pavement, run up or down stair steps, and execute hill workouts. However, most modern marathon racing shoes with carbon-fiber propulsion plates (and some modern trail shoes with propulsion plates) are excessively rigid to maximize energy return from cushy midsole foams. That’s great, but the rigidity can lead to greater instability in your gait and movement patterns up your kinematic chain from your feet to your hips, Dicharry says. He adds that it’s probably not a good idea to wear carbon-plated shoes several days a week.

6. Durability and protection

If you are a trail runner, you’ll want and need your shoes to be durable and protective. The more rugged and technical the terrain, the more durability and protection you’ll want. Those factors come partly from the materials of a shoe and partly from the design of a shoe. Key durability-enhancing materials and features to look for include a protective toe bumper, a full-length rubber outsole, reinforced sidewalls, a mesh upper that’s been enhanced by thin thermoplastic polyurethane (TPU) overlays, and maybe even a flexible rock plate sandwiched in the midsole. (Modern shoes with rigid propulsion plates also offer underfoot projection, but rock plates can also offer flexibility.) There are some trade-offs to consider, though, because the features that provide durability and protection typically add additional weight. For example, if you have a shoe with more cushioning or thicker outsole lugs, it might offer plenty of protection without a rock plate. Similarly, a shoe with a wider toe box won’t need as much of a toe bumper because your toes won’t be quite as vulnerable.