Eyes wide shut

Dear Lucy: I’m often seized by extreme sleepiness about one and a half or two hours after lunch. I’m usually much sleepier at this time of day than I am at midnight. I think many people share this experience. Unfortunately, many classes at MIT are scheduled in the afternoon, just at this “sleepy time.” Do you have any advice on how I can become more alert at this time of day? —Somnolent Sophomore

illustration of a person sleeping in the shadow of a large sundial

Dear S-squared: What a great question! You’re correct that many people share your experience of midafternoon drowsiness, and that includes Lucy. A midday nap is part of the daily routine in many cultures, and many scientists now believe that this afternoon “downtime”—which tends to occur between 2 and 3 p.m. for most people—is hardwired as part of our circadian cycle. In fact, it even coincides with a slight drop in body temperature.

Unfortunately, says MIT Medical Psychologist Xiaolu Hsi, this midday slump hits even harder if you’re already overtired, and “chronically overtired” describes most college students, especially at MIT. 

Not surprisingly, Hsi’s first suggestion for combating your two o’clock tiredness is that you try to get enough sleep at night. “If possible, this means seven to eight hours,” she says. “Try to peg your schedule to the hours of sunlight, especially when it comes to getting up in the morning,” she adds. “Staying up past midnight, and then sleeping late the next day, is not the best way to be effective in any area.”

Hsi also suggests eating a lighter lunch. Although the afternoon slump occurs whether or not one has eaten a midday meal, normal afternoon drowsiness may be exacerbated by a heavy noontime meal, as the body’s energy is diverted to the task of digestion. You might also want to go light on lunchtime carbs, since studies have shown that a high-carbohydrate meal, especially one that is also low in protein, tends to elevate serotonin levels in the brain, which causes sleepiness. “Taking a brisk 10-minute walk before an afternoon class is another way to make sure you start the class as fully alert as possible,” Hsi adds.

Finally, Lucy reminds you that one is never too old for a nap. Many studies have shown that the best way to deal with the midafternoon slump is not to fight it. Even a 10- to 15-minute nap can lead to several hours of improved alertness and productivity. And short daytime naps have been shown to be especially useful when you’re not getting enough sleep at night. Just keep naps to no more than 45 minutes—set an alarm—and don’t nap after about 4 p.m. Lucy would also add that midday naps are best taken before an afternoon class, not during! —Lucy

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