Hi, Bambu! Your body definitely needs rest, and regularly. A lot of people who get lots of exercise, will give different body parts rest and work other areas on a daily basis. From what I've read and noticed, the difficulty of your workouts can make a difference how much rest you need - i.e. a very strenuous leg muscle workout could take up to 3 days to recover from, so for the next few days, legs should do no more than light walking or spinning without resistance, but upper body could do some work....
My general approach is to have a plan, but listen to my body. If my planned rest day is Wednesday, but I feel tired on Tuesday, I'll swap them. Different people need different amounts of rest, but almost every advice I've ever read is to take at least one whole day off a week. I've also recently read to have a recovery week every 4 weeks, with lighter exercise than usual.
Hugs and butterflies,
~T~