Running is one of the most popular means of getting fit for a reason: It gives you a whole body workout, almost anyone can do it, and the only gear you need is yourself.
Today is National Running Day, and in honor of the holiday, we've put together a list of the 12 most difficult running trails in the U.S.
Let us know if we missed any.
Double Oak Trail, Pelham, Ala.
Distance: 17 miles
The Double Oak Trail in Pelham, Ala., is a 17-mile loop covering not just beautiful, lush valleys, but many steep, uphill climbs.
The terrain is rocky and has many tree roots emerging from the ground, which make for a tough obstacle course.
Grand Canyon Trails, Coconino, Ariz.
Distance: 42 miles
The elevated temperatures and high altitude can make running along the trails in the Grand Canyon a bit perilous.
But the difficulty of the route is definitely made up for by the beauty of the Canyon views and the bragging rights afterward.
Olmstead Loop Trail at Auburn S.R.A., Cool, Calif.
Distance: 8.6 miles
The Olmstead Loop Trail climbs up and down a number of steep canyons and is laborious to maneuver, especially when the trail is muddy. The Olmstead Loop is the longest trail in the Auburn State Recreation Area, a park also known for the K2 training hill, where top runners train.
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