Regardless of what you're training for, this short session will help improve your lactate threshold.
We asked a few elite runners who frequently do both.
They've made their name in ultras, but they're leaving the trails behind for one day in Boston.
The California race had a loaded field that overcame wet and muddy conditions.
Here are 5 men and 5 women to keep an eye on at the North Face Endurance Challenge Championship on Saturday.
After an epic trail run on the Kauai coast, Sage Canaday goes through everything he takes with him.
Two-time Olympic track runner Leo Manzano is now training in maximalist shoes.