Rapid eye movement sleep, commonly known as REM, is the interval of sleep during which we dream. While in this phase, our eyes dart back and forth, other muscle contractions are inhibited, and the rest of the body becomes immobile and relaxed. According to the National Sleep Foundation (NSF), we spend about 25 percent of our sleeping time in REM. The phase recurs about every 90 minutes, and lasts longer later in the night. In addition to being associated with dreams, REM sleep appears to provide a restorative function for both the brain and body. It also supports optimal daytime performance, both mentally and physically.
This phase is such an important part of our consciousness that if REM sleep is disturbed one night, our bodies don't follow the normal sleep cycle progression the next night. Instead, we may slip directly into REM sleep and go through extended periods of REM until we "catch up" on this vital stage.
Sleep in general, and REM sleep in particular, can be negatively affected by a number of factors including drinking caffeinated beverages during the day, and taking medications such as certain diet pills and decongestants. In addition, most sleep aids – both prescription and over-the-counter – suppress REM sleep, as do many antidepressant drugs and the early morning nicotine withdrawal that wakes heavy smokers prematurely.
Having an alcoholic drink to overcome insomnia can also do more harm than good. It may help you fall into a light sleep, but it robs you of REM time.
The amount of exercise we get also has an effect on our sleeping patterns, as does our sleeping environment. During REM sleep, we lose some of our ability to regulate body temperature, which means that surroundings that are abnormally hot or cold can disrupt this stage of sleep.
The surface you sleep on can have an impact on both temperature and comfort, and for many people having issues with sleep, evaluating their mattress is a good place to start. (Yours may be past its prime if it is nine to 10 years old.)
New research also suggests that improved REM sleep is associated with a comfortable and supportive mattress. A Temple University School of Medicine study measured the sleep quality of 20 participants on their current bedding and compared it to how well they slept on a mattress designed with a sophisticated system of foam chambers for adaptive support: Simmons’ ComforPedic iQ sleep system.
On average, the participants fell asleep faster, spent less time lying awake and experienced increased REM sleep. Although the study was small, the results reflect a trend toward an integrative approach to sleep that I would like to see more manufacturers embrace.
I have endorsed the ComforPedic iQ sleep system and I believe the technology it uses promotes better quality sleep and increased REM. I donate all of my after-tax profits from royalties from sales of ComforPedic iQ directly to the Weil Foundation, a not-for-profit organization dedicated to supporting integrative medicine through training, education and research.
Andrew Weil, M.D.