Hell, at the end of the day they are just some old time weights for measuring sacks of grain etc that blokes in the market started lifting to show off how strong they are. Same as nunchucks etc are just agricultural tools that someone decided to hit his neighbour with so became a wepon. Then some know-it-all wanted to cash in and decided that it had to be used in a certain way and thaT he had the power of knowledge of how they had to be used. Just pick them up and swing, lift and throw them and they will make you stronger. If something hurts don't do that way again. Same as everyone wants to life tyres or flick ropes up and down on the ground now as if it has some magical quality. It's all about makeing the body work hard in a range of motions so to work all the body just like humans used to have to do just to hunt, gather food or earn a living. Get a spade and dig a bloody big hole and then fill it in again as fast as you can and you will get a good work out, it's just about making the body work hard. I love Kettle Bells but I can't see the point of getting too hung up on it needing special qualified instructors. As long as you uses some common sense any hard work will toughen the body up.