does it have to be weighted to work your core abs and all that fat burning jiffo? i just bought mine off uk ebay (im sure there will be a huge more variety on us) and it was only £3.50 (abouts $7 ) and weighed 230g i dont think that will be heavey enough to work it if you need weight... it is one where you clip it together so wen i get i will add water or sand (Puncezilla
) or maybe even pebbles? i dunno but if i do need weight ( i have no problem keeping it up (i use my friends sometimes) so if you only need a weighted one for that then thats fine) so how much weight for an extremly fat burn calorie destroying ab strenghening ....
.... workout? thanx