Whether you’ve boxed for years or recently threw on a pair of gloves for the first time, adding a punching bag to your home gym makes it easier to develop your speed, endurance, power and technique.

Charlene Washa bobs from side to side, alternating between left and right crosses into a punching bag. Her blood is pumping, each punch bringing on a rush of endorphins. The 65-year-old from Le Center ...