The Speed Bag Is a Highly Underrated Workout
by Rachel Fairbank from Lifehacker on (#5PNC0)
If you've ever walked into a martial arts gym, you're familiar with the rapid thud-thud-thud-thud-thud of the speed bag. That small, air-filled bag that hangs on a swivel may look innocuous-especially when set against the hulking presence of the bigger, heavier bags-but it happens to be a seriously underrated form of...