appropriate rest days?

skpresley20

today was supposed to be my second rest day. At my mom's and she has an elliptical, was thinking about doing a little exercising even though it is my rest day. If I DO workout, then that means originally tomorrow starts my new week of exercising and I would have worked out for 6 days in a row. Is it bad to only allow your body 1 day of rest after 4 days of hard cardio and weight lifting just to jump back into 6 days of the same thing? how often do you take a rest day and for how long? Especially want to know how weight lifters do their rest days