I have had the Cardio Canine Belt/Leash system for several months and I never walk the dog without it.  Initially, I was interested in this system because I was suffering from lateral epicondylitis (tennis elbow) and every time my miniature schnauzer (Jazzie) took off on a regular leash, I suffered pain.  Obviously, we have worked with her and she is now much better behaved on leash, but with the Cardio Canine leash, I enjoy walking and multi-tasking.  I can drink my coffee while on our morning walks and it is no big deal when the cell phone rings since I have both hands free.  The belt comes with a handy pouch for extra bags or treats and the water bottle is great since we had already trained her to drink from a bottle.  Should the occasional bird or squirrel cross our path, I no longer cringe when Jazzie takes off since I have complete control of her from the center core of my body.  I highly recommend this great dog walking product and never leave home without it!