Trail running is an invigorating way to spend time outside – while increasing your fitness and clearing your mind you get to act like one of our primal ancestors, dashing through the woods.

Having the right shoe during that time outside is imperative. We talk to Colorado ultra runner Drew Gunn to get the lowdown on today’s trail runners.

“The main difference between a trail shoe and a road shoe is generally more traction,” Gunn said. That traction – from gnarly lugs like monster truck’s tires, with some added protection – goes a long way in adverse conditions.

Many trail shoes have a significant wrap fit to stabilize feet on uneven surfaces.

Minimalist shoes, or shoes with very little cushioning underfoot, will allow for a more natural stride, and not interfere with body mechanics. Merrell’s Trail Glove 3 is a leading minimalist style trail running shoe. At seven ounces each, these shoes feature a “zero drop” profile. While most running shoes drop heel to toe at least 7 to 12 mm, many of today’s trail shoes remain perfectly flat underfoot, hence, zero drop. Some say this can eliminate a long list of running injuries.

While zero drop and minimalist shoes are certainly popular with a growing sect of the running crowd, they can take some getting used to.

On the other end of the spectrum, maximalist shoes have ample cushioning, like running on a bed of marshmallows. Think full suspension mountain bike.

“The have a lot of cushioning and a lot of rocker,” Gunn said. Rocker is a curve in the shape of the shoe that allows it to roll forward.

Popular with technical trail runners and ultra runners, these squishy trail eaters are more precise than you’d think. They can also feature a zero drop profile, like Altra’s Olympus 2.0 , Hoka One One’s Speedgoat, with it’s deep aggressive lugs, has a rocker platform with 5 mm of drop heel to toe.

Gunn, a veteran of the infamous Hardrock Hundred Endurance Race, a grueling race through the Colorado Rockies with nearly 70,000 feet spent climbing mountain terrain, streams, snow, rain, lightning, wildly swaying temperatures and the most rugged trails on earth, likes something in between the two she types. But really, he said, it all comes down to fit.

“That’s the most important thing,” he said. “If somebody tried on a shoe and said, ‘that’s the most comfortable,’ then that’s the best shoe for them.”