Hi! I apologize in advance if this has already been discussed...I've got PUB and PLB on DVD on order, but like many others I've been thinking of ordering a video to tide me over...lol...and have been thinking about Boot Camp...my question is this: I'm an advanced exerciser, but I've never even used a medicine ball in a workout...do I really want to start with an 8-pounder as is used in the video, or should I start out with a lower poundage? Thanks.