I recently picked up a 70 pound canvas punching bag from a garage sale for $15. Not bad -- it had only been used a few times, so it's basically in new condition. New, a bag like this is about $70, so I got quite a deal on it.

I've never actually hit a heavy bag before now. All of my punching has been on punch pads held by people, or in the air -- shadow boxing and stuff. I've never hit an essentially solid object until now, and let me tell you - it's a completely different experience.

First things first: you really learn quickly how to keep yourself from punching incorrectly. If your wrists aren't aligned correctly with your two larger knuckles hitting square against the bag, you end up jamming your wrist on every heavy punch. Sucks. It took me a few times to figure out what I was doing wrong, and am now punching it fairly square each time. It's odd to think that I've never known that for all the years I've done martial arts. I'm used to hitting with sticks, or moving directly into grappling moves, so the idea of continually punching a bag is very new to me.

I don't quite have it down perfectly yet - I've identified a few things that I'm doing wrong after watching this video of myself punching the heavy bag.

1. I'm not extending like I should. Since I'm so used to grappling, I keep my arms close to keep from getting locked up. I'm pretty sure you're supposed to extend when you're boxing.

2. I'm not retracting my arms quickly enough after punching. All of my cross-punches are slow to return, which is bad. Very bad.

3. My footwork isn't completely accurate. People (myself included) have a tendancy to put too much weight on the forward foot when throwing a cross, leaving them off balance. I do good most of the time, but I can see times when my rear foot is practically off the ground, which is horrible.

Practice, practice, practice. Good stuff.