Is there such a thing as placebo sleep?

It is estimated that the average human will spent 36% of their life sleeping. If you lived to be 75 years old, 27 of those years will be spent sleeping. Sleeping is one of the most important human functions and a lack of it can affect our memory, increase impulsiveness, promote weight gain and add to stress levels.

A recent study looked at how placebo sleep affects cognitive function. Participants analyzed in the study were told that quality REM sleep constituted between 20-25% of their total sleep. One group was told that 28.7% of their sleep was in REM sleep and the other group was told that they were spending 16.2% in REM sleep during the night. The participants who were told that they had above normal quality sleep, 28.7%, scored significantly higher on the PASAT, a measure of cognitive function that specifically assesses auditory information, and the COWAT, a cognitive test of verbal processing ability, compared to participants who were told they had below average REM sleep.

The perception of how well you sleep might have an effect on how well you perform. Placebo sleep suggests that regardless of the quality of sleep, believing you had quality sleep can influence cognitive function. Talking of how tired you are can also negatively affect your ability to perform. 

Some tips for a good night sleep

• Sleep in a dark room that is slightly cool 
• Turn off all your technology (cell phones, computers, etc.) 
• Avoid consuming caffeine late in the day; ideally not after lunch 
• Seek out morning light. Sunlight in morning helps the body’s internal biological clock reset itself each day. 

Getting quality sleep helps you function properly throughout the day. It is recommended that adults, including the elderly get 7-8 hours of sleep. Teens should get 9-10 hours of sleep. Sleeping well is as crucial as eating a balanced diet and exercising regularly.

References from the SIRC Collection:

1. Al-Sharman A, Siengsukon C. Sleep Enhances Learning of a Functional Motor Task in Young Adults. Physical Therapy. December 2013;93(12):1625-1635.

2. Beedie C, Coleman D, Foad A. Positive and Negative Placebo Effects Resulting From the Deceptive Administration of an Ergogenic Aid. International Journal Of Sport Nutrition & Exercise Metabolism. June 2007;17(3):259-269.

3. BRACKO M. Sleep: THE Athlete's Steroid. IDEA Fitness Journal. November 2013;10(10):44-50.

4. Diefenbach K, Donath F, Roots I, et al. Randomised, Double-Blind Study of the Effects of Oxybutynin, Tolterodine, Trospium Chloride and Placebo on Sleep in Healthy Young Volunteers. Clinical Drug Investigation. June 2003;23(6):395-404.

5. Lloret-Linares C, Lafuente-Lafuente C, Bergmann J, et al. Does a single cup of coffee at dinner alter the sleep? A controlled cross-over randomised trial in real-life conditions. Nutrition & Dietetics. December 2012;69(4):250-255.

6. Yuuka H, Yoshiaki N, Takuro H, Sotoyuki U. The Effects of Different Intensities of Exercise on Night Sleep. Advances In Exercise & Sports Physiology. February 2014;20(1):19-24.