Sept. 25, 2000 -- The professor's life was out of whack. A busy woman, she was bushed by 8 or 9 p.m., but pushed herself to stay up working most nights till 11:30. Then came the aggravating part: "I'd be lying there till maybe 1, maybe 1:30, before I could finally fall asleep. The whole next day would be screwed up, performance-wise," says Pauline Rosenau, PhD, who is a management and policy science professor at three Houston universities.
Today, Rosenau quotes passages from the book that has become her health bible, The Body Clock Guide to Better Health. The book taught to unlock her own personal "sleep gates" -- those windows-of-opportunity for restful sleep that occur every 90 to 120 minutes each night. As it turns out she was showing up at the sleep gate at the wrong time: She is an "extreme lark," an early riser.
Rosenau was working against her body's own natural circadian rhythms. Now, she's taking her cues from them. She saves her early morning hours for intense mental work, and leaves newspaper reading for evening. Exercise has been shifted from mornings to evenings, and lunches are lighter, so she won't be sleepy in the afternoon -- and inclined to grab a cup of coffee. She goes to bed earlier than ever before, and wakes up early, too -- just as her circadian rhythms were directing her to do all along.
"It's the best I've felt in 10 years," she tells WebMD. "And it's not just feeling better ... it's productivity. I'm getting so much more done."
Most women grow up somewhat in sync with their biological clocks -- gaining a fine-tuned sense of when to expect monthly weight gain, moodiness, pimples. Get close to age 30, and that translates into the tick-tick-ticking of the biological clock.
The Body Clock takes a closer look at this internal clock, saying that a great body of research indicates that our biological rhythms -- both men's and women's -- are in a constant state of flux, adjusting every minute, every hour, says Michael Smolensky, PhD, the book's lead author.
It's based on a science called chronomedicine, which holds that this ebb and flow vastly affects your blood pressure, heart rate -- all manner of bodily processes and disease symptoms -- and can guide doctors to optimal treatment times, Smolensky tells WebMD.
"By paying attention to our body clocks, our body rhythms -- which includes 24-hour rhythms, women's menstrual cycle rhythms, and even annual rhythms -- we can achieve better health, we can understand the rhythm of alertness, we can better prevent and treat illness," Smolensky tells WebMD. "This biological clock controls when we're sleepy, when we're alert, when the symptoms of our diseases are going to be most and least intense. It will affect how we respond to medications in terms of their therapeutic efficiency and their side effects."
When Smolensky began researching the book, he found that scientific journals were full of relevant information. "There was so much information in the literature that people and doctors don't know," he tells WebMD.
Here are a few tidbits Smolensky and co-author Lynne Lamberg gleaned from their research:
- Most chronic illnesses in women worsen in the days just before a menstrual period. Also, the best time to schedule a Pap smear is near ovulation, midway between a woman's monthly periods; test results are most accurate then.
- Men produce more and faster-moving sperm in the afternoon, and having lots of speedy sperm boosts the odds of that one will reach the egg in the few days each month when conception is possible. For couples trying to conceive, several studies have shown that sperm counts are highest in spring and lowest in summer, and the late afternoon may be the best time for intercourse.
- Day 14 of a woman's menstrual cycle is a big one: ovulation occurs, conception is most likely, sexual fantasies and desires peak, orgasms are more intense, and the senses of vision and smell are more acute.
- If you're having dental work done, take note: anesthetics last about 32 minutes when given in the afternoon, as compared to only 12 minutes in the morning. Studies of patients undergoing root-canal surgery, tooth extraction, gum surgery, and other painful procedures show similar results.
- Taking aspirin and other non-steroidal anti-inflammatory drugs such as Advil with dinner or before going to bed is more effective in controlling the inflammation and pain of rheumatoid arthritis, a disease marked by inflammation in the joints. That's because the medication is in the tissues overnight and still there in the morning, when swelling is worst. Also, this reduces the potential side effects of these drugs, such as bleeding ulcers.
- The time of day you have diagnostic tests done or undergo medical procedures can alter the results. If you have asthma, for example, your airway function will vary over the day. It probably is best in mid-afternoon, and poorest in the early morning. If you routinely go for a checkup in the afternoon, your doctor may think your treatment is working fine. But if you go first thing in the morning, the severity of your illness will be more apparent.
- Blood pressure is often 20% higher in the late afternoon than in the morning. If you regularly have checkups in the afternoon, this could be telling your physician that your condition is worse than it really is.
- Glaucoma tests should be taken in the morning, when eye pressure is close to its highest.
- Some chemotherapies -- such as 5-fluorouracil, which is used to treat cancers of the intestinal tract -- are best tolerated and cause the fewest side effects when given by infusion while the patient sleeps at night. Other chemotherapies are best tolerated when given in the morning.
To truly embrace chronomedicine, says Smolensky, "physicians will need to abandon many of their current practices. They will need to throw out many norms by which they now evaluate patients. They will need to write in their charts not only what signs and symptoms they find, but when they find them. They will need to pay attention to the time of day they draw blood, and when they collect urine and other bodily tissues for diagnostic tests. They may even need to schedule tests at specific times of day or night."
In fact, chronomedicine can help people better cope with short-term illnesses such as colds and flu, episodic ones such as headaches and back pain, and persistent ailments like arthritis, high blood pressure, heart disease, cancer, and more, says Smolensky.
And "chronotherapy" -- medications developed in doses proportioned to match day and night symptom patterns -- is now replacing some standard single-dose medications. "The old 'take this medicine three times a day,' is obsolete," Smolensky tells WebMD. "In prescribing equal doses over the day, your doctor presumes that your need for medication is the same all day, and that a consistent amount of medication confers a uniform benefit at all times. That belief is wrong.
"If your symptoms wax and wane over the day, you need proportionately more medication to control them," says Smolensky. "Moreover, the way your body absorbs, uses, and excretes drugs varies over the day. The same dose of medicine may be too much at one time, and too little at another." Asthma and heart medications have been developed based on these principles.
Especially when it comes to dealing with chronic problems, like osteoarthritis, "it's essential that people learn to chart their own patterns, how their symptoms wax and wane," Smolensky says.
"When you know your own rhythms, when you're most functional, you optimize your quality of life," he says. "You get more things done, enjoy your social interactions more."
Correction: The original version of this story included the incorrect name of the book. It is The Body Clock Guide to Better Health. Also, co-author Lynne Lamberg's name was misspelled.