The Truth About High-Intensity Interval Training (HIIT)
What Is HIIT?Core principlesHave you ever sprinted up a hill, then walked down to catch your breath — and felt like you’d done a day’s work in ten minutes? That’s…
What Is HIIT?Core principlesHave you ever sprinted up a hill, then walked down to catch your breath — and felt like you’d done a day’s work in ten minutes? That’s…