me takin an off every 4th day , i only do normal cardio like tread or ellipti and crunches on the 4th day.
i guess takin the 4th day off resistance training gives my body some time 2 heal . as shred isnt the only workout i do.
id also recommend others like me , im a lot bigger than i should be
to go with their own pace , intensify, modify , extend cardio n crunches etc.
the workout is a blast goes without saying . but the "20 min...." thingy is a publicity gimmik, to attract ppl who dont have enough time to spare.
do more if u like..... it s good. but listen 2 ur body dont hurt it. push it ... but know when 2 stop.