Imagine running with a view of the Pyramids of Giza or inside the valley of a dormant volcano. The new book 100 Runs of a Lifetime has a must-visit destination for anyone who loves a good run—no ...

For fitness enthusiasts who need a little cardio variety, HIIT (or high-intensity interval training) has long been a popular choice. According to a study in Biology of Sport, HIIT — which pairs short ...