Choosing Trail Runners

Understanding the Trail Runner

Since soft cushioning can lead to a turned ankle, most good trail runners depend on fairly stiff midsoles (dual- or triple-density EVA foam). The outsoles are rugged, (made from carbon or blown rubber, or a combination of both), and feature aggressive tread patterns.

Uppers are usually water-resistant and made from durable synthetic leather or nylon mesh materials. Toe-rands ward off rocks. Additional protection is usually provided by molded nylon flex plates in the forefoot (look for flex grooves in the forefoot outsole to enhance natural flex).

Support is also important and is delivered to trail runners by burly medial supports and beefy heel counters. The lacing system is generally advanced, offering a variety of means to get a snug fit.

Know Thy Feet

Three important factors to consider when making your choice are the size, shape and mechanics of your feet.

Foot size
You probably already know your shoe size. If you're not exactly sure or if one foot is larger than the other, it's best to have your feet measured with a Brannock device. (That's the flat metal thing with sliders that measure the length and width plus the toe-to-ball length of the foot.)

Foot shape
Next you need to know the shape of your foot. Do you have high arches? Are you flat-footed? Do you have a "normal" shape foot? (If so, you are in the minority!) Here's a simple way to find out. As you get out of the tub or shower, or step out of a pool, take a look at the footprint you leave on the bathmat or cement. The width of your footprint will suggest the shape of your arch and the way your foot moves as you run. Generally speaking, the wider and straighter the footprint, the lower your arch is. A very narrow, curved footprint (or one in which the ball and heel are not even connected) suggests a high arch. Somewhere in between these two is that so-called "normal" foot.

Running mechanics
Foot shape is closely related to its movement as you walk or run. Typically, as your foot strikes the ground heel first, it rolls slightly inward, flattening the arch to cushion the force. This inward movement is called pronation. Next, your foot rolls slightly to the outside, stiffening up and creating a springboard that propels the next step. The outward motion is known as supination.

Many people experience different levels of these sideways motions as they run. Many over-pronate, meaning that their feet are overly flexible and roll too far to the inside. This is commonly, although not always, true of people with low arches. These folks need extra support and motion control.

Some runners supinate (more commonly referred to in the footwear world as under-pronating.)This means they run on the outside edges of their feet, which in turn don't absorb much shock as they land. This is frequently the result of inflexible feet and high arches. The preferred shoe for this type of runner offers plenty of cushioning and flexibility. But how do you determine what sideways motion your foot makes? The answer is probably in your closet.

If you own a pair of "experienced" running shoes, check the wear pattern on the soles to see whether you over- or under-pronate or if your foot motion is normal. If the wear is centralized to the ball of the foot and a small portion of the heel, you have a normal amount of foot movement. Over-pronation is identified by wear patterns along the inside edges, while under-pronation is marked by wear along the outer edges.

Where You Run

Most trail runners have soft, grasping outsoles that wear quickly on pavement. They are perfect, however, for mountainous trails where you'll encounter steep angles, tight turns, and areas where a soft step is followed by a hard impact. Some shoes have outsoles more suited to dry trails while others are better for mud and goop.

Groomed Trail or Fire Road—Look for good traction, cushioning and stability.

Rocky Trails—Look for good forefoot protection, toe-rand, heel counter, dual density EVA midsole, aggressive tread.

Road and Trail—Look for a shoe with extra cushioning (gel or air) combined with good traction and a stable midsole, usually with dual-density EVA foam.

Slop, Mud and Rain—Think waterproof/breathable liners, water-resistant or wicking uppers. Spandex Lycra- and Gore-Tex®-type laminates are most often seen in these shoes. Also, look for a very aggressive tread with wide-spaced lugs to shed mud. Rather than cushioning, go for stability.

Dry conditions—Moisture-wicking shoes are key. You can go with extra cushioning, but keep in mind the trail type on which you commonly run.

The Shoe That Fits

In trail shoes look for a very secure fit in the heel and arch but with a bit more room in the toe. The way you tie your shoes can help in this area—keep the laces somewhat loose at the bottom and tight at the top of the foot. Trail runners should have a high scree collar around the ankles but a low heel tab at the top of the heel—the better to run down hills. Partially curve-lasted shoes typically provide the best fit for trail running. Learn more about getting the right fit.