By Renan Abagat, Physical Therapist
STRETCH Wellness Newsletter
This JOI Rehab Newsletter is focused on sleep related topics. How much sleep do you really need and tips on how to improve your sleeping habits are discussed in this issue.
It has been an age old adage: how many hours of sleep do our bodies need to recuperate so we can wake up the next morning refreshed and ready to face what the day brings? As the demands of life increase in number and complexity, let us look at the effects of temporary and chronic sleep
deprivation. It may surprise you to learn that sleep deprivation, for whatever reason, can significantly affect your health, performance and safety.
According to an article by Michael J. Breus, PhD, sleep deprivation in the short term decreases alertness and performance. Reducing nighttime sleep by 1 ½ hours could result in 32% decrease in alertness. Sleep deprivation can impair memory and cognitive ability as well as disrupt our relationships with others secondary to mood changes.
According to the National Highway Traffic Safety Administration (NHTSA), drowsy driving is responsible for at least 100,000 accidents, 71,000 injuries and 1,550 fatalities each year. Decreased alertness can lead to a two-fold increase in risk of sustaining an occupational injury. Untreated sleep disorders that cause chronic sleep deprivation can lead to:
- high blood pressure
- heart attacks
- psychiatric problems (including depression and mood disorders)
- mental impairments
- fetal and growth retardation
- disruption of bed partner’s sleep quality
- poor quality of life
How much sleep do we really need?
The longest sleep restriction study was done by David Dinges and Hans Van Dongen at the Sleep and Chronobiology Laboratory at the Hospital at
University of Pennsylvania. This study suggests the lack of sleep affects our ability to sustain attention as shown by the Psychomotor Vigilance Task (PVT). This measures the sustained attention that is vital for our day to day activities. The study showed that those who had 8 hours of sleep hardly had any attention lapses and no cognitive declines over the 14 days of the study. Those who had 4 hours of sleep and 6 hours of sleep showed a steady decline in sustained attention with each subsequent day. Although the 4 hours of sleep group performed far worse, it is interesting to note that the 6 hour group also consistently fell off-task. By the sixth day, the 6 hours of sleep group experienced five times as many attention lapses as they did the first day. So, if 8 hours is ideal and 6 hours puts us at risk, what about 7?
A study by Gregory Belenky to see the effects of odd numbers of sleep hours showed that those who slept for 7 hours each night had slower response time to the P.V.T. and continued to decrease for 3 subsequent days before stabilizing at lower levels than when they started. The study by Dinges also showed that some people who need 8 hours of sleep will immediately feel the effects of a single night of 4 hours of sleep while others can handle experience several 4 hours of sleep a night before a decline in performance is noted. However, there is a small portion (5% or less) of the population that for whatever reason can maintain their performance with five or fewer hours of sleep. Before you reach for that next cup of coffee to wake you up during the mid-afternoon work hours, think about ways you can get enough sleep the next night. Sleep not only keeps us beautiful on the outside, but most importantly from the inside as well. It can enhance of:
- improve our memory
- cognition and relationships
- keep us safe
Sources: Sleep Habits: More Important Than You Think, Michael J Breus PhD. WebM
If you are interested in scheduling an appointment at JOI Rehab for physical therapy, go to: JOIonline.net or call 904-858-7045https://www.joionline.net/stretch/April2012WellnessNewsletter.pdf