I like to hike, a lot, but I just do not understand this:
Outdoor adventurers call this pastime speed hiking. It combines the muscle-building benefits of altitude gain with fast-paced aerobic activity, which keeps heart rates high. Fast hikers usually wear lightweight footwear and hydration backpacks and minimize what they carry. Most trips are done in a day.
(New York Times [1])
If all you want is the exercise, buy a treadmill.
H/T: Breitbart [2])