Ive talked about exercise a few times on the forum…I'll cut and paste what I've explained…. But it's up to you….just know that exercise builds muscle which weighs more than fat…so dont freak out by the numbers on the scale of you exercise…because the numbers could increase even though you're still losing body fat…here are my comments from the forum:

"When people ADD exercise/working out to the Detox phase, that definintely changes
their results as exercise can stimulate hunger and cause you to build muscle
mass, which weighs MORE than fat. So, you notice that I dont include exercise
as MANDATORY in Phase 1 during the detox phase. In the DEM System, we purposely
made "get moving" (being physically active) the third phase so we
could focus people on changing their eating habits. What you eat is 3 times more
important for weight loss than working out.  So, it's up to the
individual to decide if they want to incoporate exercise and how this effects
their results on the DEM System. At best, light walking is good during the
Detox phase, but by exercising you could actually be LOSING body fat but
gaining muscle mass and the scale WILL show O POUNDS LOST as muscle
weighs more than fat.  So, you could actually be losing body fat but the scale
wont' show it as you are ALSO gaining muscle mass by working out.