Most people live very hectic lives and they don't get the rest or sleep that they need. If you are training hard then you need rest to recharge your batteries. There was an article in the 1970 Ironman Magazine written by Arthur Jones the creator of Nautilus workout machines. Arthur Jones basically took some of these bodybuilders in and told them to sleep and rest for the next 3 nights and days.
Most bodybuilders overtrain.
By simply resting the bodybuilders were able to get their muscles to recuperate and grow. Apply the following rules to your routine to make your muscles grow. Keep vigorous activity on your days off to a minimum Take a week off after 6 months of steady training If you get the rest you need your muscles will grow.