Quetion about chains?

I will try to answer this question as simple as possible. The purpose of Bands and Chains is to provide Variable Resistance, or a constant amount of resistance throughout the entire range of motion or lift. Nautilus machines were based on this principle of variable resistance, the idea was to take out the easy part of the lift due to leverage, for example during a squat as the athlete ascends from the bottom position the lift naturally becomes easier due to leverage. Bands and Chains eliminate making an exercise easier due to leverage because as the athlete ascends from the bottom squat position, links of chain will come off the floor or the band will stretch which will make the exercise harder instead of easier. I know a powerlifting friend of mine who currently trains his son for AAU powerlifting. He trains almost exclusively with bands and chains and his son does currently hold the AAU Bench Press record.There are strength coaches who swear by this type of training and otheres such as Boyd Epley in his book "The Path to Athletic Power" discourages band and chain training, he feels that if a lift slows you down then it will make you less explosive. There is a good article by Bryan Dermody assistant strength coach at Iowa and his views about Band chaining. It can be found (http://www.momentummedia.com/articles/tc/tc1306/bands.htm)
I hope this helps.
Gary
www.athleticpe.com