Sleep can affect weight, memory, says book
Humans spend one-third of their lives sleeping, yet 65 percent of Americans are sleep deprived, says sleep expert James Maas, co-author of the new book "Sleep for Success! Everything You Must Know About Sleep but Are Too Tired to Ask" (AuthorHouse).
But just one extra hour of sleep per night can greatly improve a person's mood, alertness, health and productivity, says Maas, professor of psychology at Cornell.
In the book, co-authored by Cornell graduate student Rebecca S. Robbins '09 while she was an undergraduate, Maas presents the latest scientific research on sleep, much of it conducted in his Cornell sleep lab, where he recently studied the sleeping patterns of 450 Cornell students.
Maas and Robbins wrote the book with significant help from Sharon Driscoll '12 (while she was a sophomore); Hannah Appelbaum '06 (now in graduate school in social work at Emory University); and Samantha Platt '10 (now in physician assistant school). They are all featured on the book cover and work as part of Maas and Robbins' consulting firm, Sleep for Success, giving presentations on sleeping better to Fortune 500 companies, preparatory schools and such groups as the New York Jets and Orlando Magic.
Their presentations and the new book report such findings as:
- The best predictor of longevity is not exercise or nutrition, but quality and quantity of sleep;
- Most people overestimate the amount they sleep each night by nearly one hour;
- If you fall asleep within five minutes, you are sleep deprived, since the fully rested person takes 20 minutes to fall asleep;
- Women sleep less soundly with a partner than men do; perhaps that's why some 23 percent of American couples sleep apart;
- Every additional hour of sleep reduces a child's risk of obesity by 9 percent;
- One drink of alcohol on six hours of sleep has the same effect on one's ability to drive a car as three to four martinis on eight hours of sleep;
- The best time to exercise is between 5 and 7 p.m. to enhance the depth of nighttime sleep.
Maas' recent studies on high school and college students support the idea that the circadian rhythm of the teenage brain is set to fall asleep at 3 a.m. and wake up at 11 a.m., yet most high school and college students get 2.5 hours less sleep per night than recommended. Grades in high school and college are directly related to sleep length as evidenced by the increase in students' G.P.A. and other measures in studies Maas has conducted.
The book also includes two tests to help the reader determine how well they sleep, the costs of sleep loss and research findings that link poor sleep with colds, flu, unhealthy skin, weight gain, diabetes, heart disease and cancer, as well as stress, anxiety and depression.
In the second half of the book, Maas offers strategies for getting a healthy night's rest -- from the best and worst bedtime snacks and the ideal bedroom environment to tips on purchasing the perfect pillow and mattress and taming a snoring partner (such as tying a tennis ball to the back of his or her nightshirt to keep the snorer on his/her side and less prone to snoring).
The book also includes advice on sleep tips for teens, seniors, shift workers, athletes and women who are pregnant or going through menopause as well as time-management advice to combat stress, tips for managing jetlag and guidelines on sleep medications.
Maas has been teaching Psychology 101 at Cornell for 47 years, with an enrollment of 1,600 students some years, giving him the record for having taught more than 65,000 students in his Cornell career.
- It takes one hour of sleep to pay for every two hours of wakefulness. Thus, the ideal amount of sleep is eight hours per night.
- Even if you fall asleep and wake in the same position, chances are you've tossed and turned as many as 60 times during the night. Movements mark the transition periods between sleep stages. Only in REM sleep is there no movement.
- Sleep deprivation costs the United States $66 billion annually in lost production, accidents, illness and premature death.
- Drowsiness and fatigue are responsible for approximately 80,000 car accidents per day in America. These crashes result in an estimated 1,500 fatalities and 71,000 injuries each year.
- Stress is the No. 1 cause of insomnia; 65 percent of Americans say stress disturbs their sleep.
- High school and college students are the most pathologically sleep-deprived population in the nation -- 86 percent of teens don't get enough sleep. Thus, teens are 71 percent more likely to drive drowsy and/or fall asleep at the wheel compared to other age groups.
- After 17 to 19 hours without sleep, brain activity is similar to someone with a blood alcohol content of .05 (.08 is the legal limit for intoxication).
- In REM sleep, the previous day's events are solidified into permanent memory traces, and sequences of learned skills (like a new golf swing) become muscle memories.
- Sleeping longer than six hours per night helps in memory retention, but it takes eight hours to fully incorporate learned material. Thus, getting a full night's sleep after studying for an exam, rehearsing a presentation, or learning a new set of skills is most beneficial.
- If you sleep eight hours, you'll dream three to five times, spending about 100 minutes in your theater of the night. Dreams occur about every 90 minutes during sleep and last from nine to 30 minutes or more.
- People who are extroverted seem to remember more of their dreams than those who tend to be more guarded and introverted.
- Staying in bed longer can actually keep you from gaining weight. The less sleep you get, the less efficiently your appetite-regulation system works.
- The ideal room temperature for sleep is 65 degrees Fahrenheit. The ideal naptime is 20-90 minutes.
- The weight of mattresses doubles every 10 years due to dust mites so be sure to invest in a new one every decade. Stick with 100 percent cotton sheets for their absorbent and breathable quality.