The Importance Of The Heavy Bag

Out of all of the training equipment out there, which is the most important? I say the heavy bag. Many people feel that pad work is the most important. The big bag helps you develop power, speed, and endurance. The constant resistance of hitting the bag makes you strong and explosive. You have to incorporate movement, defense, etc. in your bag work and not just go through the motions. Here I am on the bag. http://www.youtube.com/watch?v=pcoQJL331CM