The lack of sleep has many side effects that affect your day to day life and your future health, from fatigue and loss of concentration to the possibility of not feeling like a person without having your caffeine fix. In general, sleeping in a little longer sometimes, of course, can be good for you, it allows you to catch up on some shut-eye and allows your body to relax. We spend up to one-third of our lives asleep. It’s important to remember that sleep is just as important as eating a healthy diet and getting enough exercise. The desire to spend more than 8–9 hours sleeping is rather tempting but it’s important to remember that sleeping more can, in fact, increase tiredness.