Hi
Depending on what level you are doing, with SS or SS+ it is recommended not to exercise, as mainly due to the low calorie intake and you are sort of "fighting" what you are trying to achieve, i.e people (including myself may i add) stick to this diet because of the results, however when you exercise, your body builds muscle and retains an awful lot of water, so "weightloss" is reduced dramatically, also because of the diet the muscle cant repair itself as quickly as it would normally!
Hope this helps - so to answer your question, put your feet up, watch a bit of tele, dont cheat and watch the weight come off!!