This finding is important because it affects a significant number of middle-aged people, who comprise the majority of the work force, said Dr. Carrier.
Middle age is a turning point for sleep.
Some sleep patterns have already changed significantly by the time an average adult reaches age 30. Dr. Carrier and her colleagues tracked sleep patterns in 110 healthy study volunteers 20 to 59 years of age, and found that sleep changed dramatically between the 20s and the 50s. They found that, with age, people go to bed and get up earlier, sleep less, wake up more during the night, have more light stages of sleep and fewer deep stages. The biological clock regulates the timing of our psychological and physiological functions so that they are in tune within the individual and with the environment. For example, it will tell your body when it is time to go to bed and when it is time to be awake.