by Brian Metzler

Many of the new trail runners available this spring are light and low to the ground; some, though, are beefy and cushy. But all are geared at helping runners move more efficiently and with fewer destructive side effects.

How is that possible? Ultimately, the trend is about running with better form (foot strikes near the mid-foot and not at the heels) and less restriction. Up until recently, most trail shoes were designed with stiff midsoles, reinforced uppers, thick heels, pronation-control, and aggressive outsoles. Those designs were well-intentioned, but, collectively, they tend to restrict runners' feet and prohibit them from moving naturally.

The ultralight low-profile designs (from Salomon, Vibram, and Pearl Izumi, among others) provide greater proprioception—allowing the runner to "feel" the trail and let the foot adapt to the terrain. When the brain senses the characteristics of the ground—firm, slippery, sloped—it positions the rest of the body accordingly to preserve balance and momentum.

That's the deal with the minimalist shoes. The key to the freakishly rockered and lifted shoes (from Hoka One One and Tecnica), though, is a rolling midsole design that transfers downward impact into forward momentum. Instead of offering a more intimate connection with the trail surface, these shoes give a sensation of floating over the rocks, roots, and rubble underfoot.

Minimalist and rockered designs are important innovations with real benefits for the right users. But mind the transition to either type of shoe: Both feature considerably lower heel-to-toe slope angles, which means the foot is in a more level position. That allows for more natural movement of the foot, but, initially, it can strain the calf and Achilles. Start with short distances and move up gradually over weeks. You don't want to run 10 miles on day one heel striking in a shoe with no heel. Brian Metzler is the co-author of Natural Running: The Simple Path to Stronger, Healthier Running. velopress.com.

Minimalist

New Balance Minimus Trail

Running in these featherweight minimalists is like strapping wings on your feet. There's just enough cushioning and tread to protect your feet from hazards. And there's nothing to hold you back.

$100; 7.5 oz. (men's 9), 6.5 oz. (women's 7); newbalance.com

Low Profile

Saucony Peregrine

These easy-flexing midrange cruisers smartly straddle the fence between too much and not enough. They're light and have a low-profile design, but don't feel like slippers. Versatile enough for any type of trail.

$90; 9.7 oz. (men's 9), 8.2 oz. (women's 7); saucony.com

Rocker Runners

Hoka One One Mafate

Although almost cartoonish in appearance, these trail monsters—which have twice the surface area of a typical shoe—plow over rooty, rocky terrain the same way a rockered ski handles bottomless pow or 29er wheels eat up singletrack.

$169; 10.8 oz. (men's 9), 9.6 oz. (women's 7);  hokaoneone.com