I am on the three day get lean program, and wondered why there are exercises for calfs and forearms in every workout. This is not a complaint, just a curiosity...

For all of my initial programs (Get Lean, General Fitness, Strength and Power etc) each muscle group is worked twice per week, once a little harder and once a little easier. If you are on the 3 Day Get Lean Program you will have the forearms and calf training on Workout #1 and #2 but not on #3. Working each muscle group twice per week is one of the best ways to achieve overall development. If you worked a muscle only one time per week it would be hard to create enough stimulus for that muscle to respond. Unless you were a very advanced lifter and trained so hard you needed to rest for a whole week before training that muscle group again, which some people can do! Also, training a muscle group more than twice per week is usually not the best thing to do unless it is something to do with the leg muscles. Then, if the work out is not overly intense you could be ok by training, say, 3 times per week on your legs. But, again, training each muscle group twice per week is the best way to go!