Austin is home to a huge running community that trains hard and plays hard on the Boardwalk Hike-and-Bike Trail, a 10.1-mile path around Lady Bird Lake is the city's most popular running route. Bridges make it easy to run loops from a 5K to the full 10 miles. The Trail Foundation, a nonprofit trail steward, estimates that it's used by up to 15,000 people each day.