I gave a talk at a local Running Room last week, where I opened by asking if anyone has tight hamstrings. Guess how many raised their hands. If your guess is about 90%, you’re right. I then asked half the attendees to lie on their backs while the other half observed. I instructed those on the floor to place their arms on the floor at their sides with palms facing up, and straighten their legs with toes pointed toward the ceiling. I then asked them to keep both knees straight and lift one leg up as high as they could.