Welcome back to standard time, folks… did you remember to set your clocks back this weekend?
One more question: did you notice it was much easier to adjust to the time change this weekend than to the switch to daylight savings time in the spring? It seems logical, since we “gained” an hour of sleep on Saturday night. But even beyond that, this is the one weekend out of the year when the external clocks match most closely to our internal biological clocks.
Yes, we do have a biological clock — a part of the brain called the suprachiasmatic nucleus (SCN); its job is to keep track of the daily cycle of our body’s functions (also known as our circadian rhythm). Research has shown that for most folks, the SCN is actually set to a 25-hour cycle, which means that we have to reset it every day based on cues in our environment. That’s why it’s easier to stay up late, but harder to wake up earlier in the morning.
Up till about 200 years ago, our biological clocks mostly relied on the signals of sunlight to reset ourselves each day. With the advent of reliable timekeeping, we now go by a strict 24-hour day; with electric lights, we can give in to our tendency to want to stay up later, if we choose.
Use the “extra” sleep you got this weekend to honor your body’s natural circadian rhythm. Don’t complain about the early sunset, but rather use it as a signal to get to bed at a reasonable time — and enjoy the earlier sunrise these days. Sleep is one of the foundations of health, and most adults need around 7-8 hours per night. Getting adequate sleep helps not only with our daytime energy, but also with preventing diabetes, cardiovascular disease, and obesity.
This is a repost of an article that appeared in 2011.
