Although many people end up waking later and retiring earlier during the cold, dark months, thereís no real biological need for getting extra sleep during the winter. Thereís more variation in sleep needs among individuals than there is in a single individual between seasons. That is, some people naturally need more sleep than others need in order to function optimally, and that number doesnít change with the seasons.
Even though our body clock is triggered by light and dark, our sleep needs donít correspond exactly with the length of the days. Think about it: in Scandinavian countries where there may be only a few hours of light per day in the winter, people donít suddenly need eighteen or twenty hours of sleep per night. Likewise, in the summer when there are only a few hours of darkness, people arenít suddenly able to get by on only two or three hours.
The imbalance of light and dark is a prime culprit in the development of seasonal affective disorder (SAD), a wintertime malaise characterized by fatigue, depression, and weight gain. Sound familiar? Itís no coincidence that treatment for SAD commonly includes light therapy to reset and regulate the bodyís circadian rhythms.
If youíre already getting your optimum amount of sleep, you donít need extra just because itís winter. But if you regularly donít get enough, feel free to fight the freeze by staying snug in your bed as long as possible.