Some of us feel that sleep is a luxury. Demanding jobs mean getting up early, and for some of us going to bed early feels like you've lost the day, so we compensate by sleeping less. But is that good enough? The oft-cited optimal level of sleep for an adult is the magic eight hours. However, individuals vary in their sleep needs from as little as five hours to as much as ten hours per night. Feeling drowsy during the day might mean you're not getting enough winks, so how can you tell if you're sleeping too much or too little?
A recent study conducted at the University of Westminster has concluded that there are people who are at their best and who are ready for action first thing in the morning, and another group who just cannot do mornings well. This may seem obvious, but why are some people early birds, and others night owls? The group who were awake early in the morning was found to have higher levels of cortisol, a stress hormone, than those who prefer to sleep in. The results of this study indicate that there may be a physiological difference between early risers and late sleepers. The difference in cortisol levels may also contribute to different temperaments between the different sleep groups. Those who awaken early in the morning, tend to be busier and more concentrated, but are also angrier and have less energy at the end of the day than their late-rising counterparts. In late-riser group, people are more likely to be relaxed and less busy. Cortisol is a hormone known to affect both mood and concentration. While it's hard to specify an ideal time to get up in the morning, if you're feeling stressed there is an increased chance you'll feel better if you add an extra half an hour of sleep to your night.
What about the effects of sleep deprivation? It is well known that sleep deprivation can be dangerous, especially if you are driving or using heavy machinery. The effect on driving may be as dangerous as driving under the influence. Not sleeping enough can also suppress your immune system and increases your perception of pain.
Most scientists believe eight hours of sleep is a safe amount and is enough to function comfortably. If you're alert during the day, then chances are you're sleeping enough. However if you feel a dip during the day, then even a 10- or 15-minute nap can make a big difference in your concentration and performance. If you can't get enough sleep on a certain day, you can always make it up afterwards. Sleep longer by going to bed earlier, sleep in on the weekend or even take a nap to help to replenish the sleep debt left. In general, however, try to have a regular sleep schedule to keep your body as rested and ready-to-go as possible.