Check out the weekly text article by Mr. Majid Koozehchian titled "Using Chains May Improve Your Strength and Conditioning." "In recent years, strength training with unconventional objects has become popular (1). One unconventional method that has gained recognition by elite athletes is adding chains to the end of conventional barbells. There are many claims that this type of training can improve strength and power above those achieved by traditional free weights (2)."