How effective is wearing weights? -I use to go to school wearing ankle weights, I'm not sure how effective it was. -I'm interested in wrist weights but not sure if its better to just practice w/ a heavy racket. -Body weights? I'm not sure if this exist, but if I wore a body weight vest, what advantages/damages exist? Also, would wearing weights daily, all day, do more harm than good? Maybe you would just have to start little first than maybe you can support heavier weights w/o killing yourself? Any info/opinions on wearing weights would be appreciated.