We’ve Got Rhythm

Biorhythms

Our lives are partly governed by potent, persistent, cyclical forces of body and mind. It can be useful to know about the biological rhythms that influence our actions and emotions, the better to understand and make prudent choices for ourselves.

There are three main types of biorhythms, based mainly on their frequency: (1) Circadian rhythms occur roughly once every twenty-four hours (circa one day); (2) Ultradian rhythms occur more frequently than daily; and (3) Infradian rhythms happen to us less often than daily. Let’s take a look at what we know and hypothesize about these natural patterns that partially direct our feelings and behaviors.

The sleep-wake cycle is guided by circadian rhythm: We automatically begin to feel sleepy at about the same time every night, and we start to stir and awaken around the same time each morning. Many people maintain regular bedtimes (even on the weekends). And everyone has experienced waking up from sleep just before one’s alarm clock is set to go off in the morning. Our biological clocks know how to tell time. One ramification of this is the phenomenon of “jet lag”. If you fly across a few or many time zones, you throw off that natural sleep-wake cycle; e.g., travel from NY to Alaska means a change of four hours, so 9:00 p.m. will feel like 1:00 a.m. (past your normal bedtime?) upon arrival, and the next morning you might feel like getting up at 8:00 a.m. Eastern time, only to find no one else awake at that hour (4:00 a.m. Yukon time). It may take days to adjust to the differences in daylight, social conventions, and business hours of a new location. In the meantime, research has linked errors in judgment, fatigue, accident proneness, headaches, mood disruption, and other ill effects to jet lag. More common than bona fide jet lag due to travel is disruption of the sleep-wake biorhythm via sleeping in on the weekends. If you typically arise at 7:00 a.m. for school or work, but stay in bed until 11:00 a.m. on Saturdays and Sundays, you are in for a rude awakening on Monday morning: it may feel as though you’ve just flown to Alaska and back. No wonder some refer to the start of the school/work week as “Black Monday”; it’s hard to get up and get going with energy and lucidity. Self-induced jet lag may be avoided by following one simple (but perhaps objectionable) guideline: Sleep in each weekend morning no longer than one hour past your normal weekday wake-up time.

Another circadian rhythm we may notice is that which influences digestion and elimination. People who are “regular” tend to go number two at about the same time each day. Science has told us not to be alarmed if our bowel movements occur more or less frequently than daily, but know that it’s not strange to be a creature of toileting habits. Physical energy and mental focus may also fluctuate on a roughly daily basis. Some people, for instance, are “doves” who feel most alert and productive in the mornings, while other folks (including many teenagers) are “owls” who seem to concentrate and perform best during evening or nighttime hours. Morning classes in school may truly be challenging for somnolent adolescents, just as some in the working world find it hard to rev up their brains in the morning and prefer to get more tasks done during the hours of darkness. Others, of course, like to get up before dawn to attack the chores of the day nice and early.

Ultradian rhythms likewise affect our daily lives. The most prominent example is the sleep/dream cycle which proceeds through several stages: (1) you turn off the lights, settle down, perhaps experience little muscle twitches, and drift off to sleep with alpha brainwave patterns; (2) your heart rate slows, your body temperature drops, and the theta brainwaves include sleep spindles; (3) you sink into deep sleep characterized by delta brainwaves, low blood pressure and breathing rate, muscle relaxation, and physical restoration as you lie relatively motionless with little cognitive activity; and (4) you phase into essential REM (rapid eye movement) sleep during which your breathing is shallow, dreams are most vivid, and body is relaxed and immobilized. REM sleep is necessary to process the events of the day and to replenish our brains to be ready for the next day’s experiences. REM precedes a lighter moment of sleep, one during which we might awaken with dreams fresh in mind, ready to roll over to a new posture before resuming the cycle that lasts approximately 90-110 minutes. What few people realize or think about is the fact that the sleep/dream cycle continues, albeit weakly, during the day. About every ninety minutes, therefore, we are more likely to feel distracted and daydream for a few minutes. When you read a page of a book or other text, then realize that you failed to process and comprehend what you just read, you need not feel mentally feeble; you simply succumbed to the natural drive to daydream a bit (akin to REM sleep). When you’re speaking and your listeners suddenly erupt into yawning fits or staring episodes, it need not be due to your being boring but rather, instead, to the time in their sleep cycles when they naturally space out. Consequently, the best advice is to take breaks. When you feel groggy or foggy, it’s time to get up, move around, stretch, have a drink of water, and then return to task.

Some other Ultradian rhythms have low-key effects. For example, studies have shown that we tend to breathe primarily through one nostril more than the other, and that dominance shifts every 90-120 minutes. Our stomachs need about that same span of time to empty their contents of a meal, with digestive processes following suit. Our appetites tend to fluctuate accordingly. Have you ever wondered why you can get up from a big meal and soon experience a case of “the munchies”? Your stomach may be full, but your body and brain suggest that your mouth wants to taste a snack. For weight management, and overall health, it is suggested that you fight your way past that episode, secure in the knowledge that your longing for food will subside in just a few minutes—before returning to mind about 90 minutes thereafter! Shifts in thirst, urine production, oxygen consumption, and brain wave patterns likewise occur multiple times each day.

The most well-known Infradian rhythm is the female menstrual cycle. About every twenty-eight days, post-pubertal (and pre-menopausal) women may experience premenstrual syndrome (PMS), more or less intensely, followed by their periods; ovulation ensues about two weeks thereafter. Women (and perhaps their significant others) may choose to prepare for, and adjust to, that natural cycle. Might men experience a similar cycle as that of women? Men tend to complain of sexual “need”, feeling “horny”, and elevated sex drive periodically—more often than monthly. Sexual fluids may accumulate and fantasies might increase in frequency and intensity, helping to explain sexual requests/demands, susceptibility to pornography, and periodic “wet dreams” (nocturnal emissions). Hopefully, sexual harassment or predation does not surface. Men should be aware of their biorhythmic tendencies and “cool their jets” as appropriate.

An Infradian rhythm that occurs even less frequently, and may range from subtle to intense, is that associated with changing seasons. Some people suffer debilitating depression during their winter doldrums, or seasonal affective disorder (SAD). Research suggests that the problem stems from mal-illumination, a shortage of natural daylight in winter when we have fewer hours of daytime available and the weather may be too cold and forbidding to encourage outdoor excursions. The most commonly prescribed remedy is light therapy—daily, short-term exposure to artificial sources of either bright or full-spectrum light. Better yet, dress for the wintry weather and spend more time outside. I suspect that everyone, to a greater or lesser degree, experiences some measure of the blahs and blues during the shorter days of fall and winter versus the lengthening days of spring and warm sunshine of summer. Winter walks and sports (e.g., skiing, snowboarding, sledding, skating, snowballing) help to maintain our fitness and keep our spirits up. Moods lighten with enlightenment!

We’ve got rhythm. Our bodies and minds keep tempos in sync with biological processes, environmental cues, and cyclical patterns. It pays to understand and harmonize with those natural forces in the interest of self-regulation and emotional well-being.