The Value of Sleep

The primary focus of previous research has been to identify correlates of sleep quality. A wide range of factors have been investigated that, for ease of description, can be grouped into three clusters. First, there have been a handful of investigations of the correlation between perceived sleep quality and PSG-measured sleep parameters. These studies have included older female normal sleepers,8 older adults with insomnia, young adult good and poor sleepers, and individuals with unipolar depression. The consensus to emerge is that poor sleep quality estimates are associated with reduced Stage 1 sleep and more Stages 3 and 4 sleep.

“Sleep is a cornerstone of weight management because of the impact it has on your hormones that control how you burn fat, how you store fat, and how you’re maintaining muscle. The better your hormone balance, the better your weight management. —Jillian Michaels, The Biggest Loser Trainer Getty Images

While sleep requirements vary slightly from person to person, most healthy adults need between 7 to 9 hours of sleep per night to function at their best. Children and teens need even more. And despite the notion that our sleep needs decrease with age, most older people still need at least 7 hours of sleep. Since older adults often have trouble sleeping this long at night, daytime naps can help fill in the gap.

The broad aim of this study was to conduct a detailed and systematic investigation of the subjective meaning of sleep quality among individuals who met DSM-IV-TR diagnostic criteria for insomnia, relative to a group of normal sleepers. This is an important gap in the literature as the majority of previous research that has attempted to systematically examine sleep quality has been conducted with individuals who are normal sleepers.

Lying awake is frustrating, he adds, and can lead to anxiety and continued sleep problems. To avoid it, reserve the hour before bed for relaxing activities—that means no work emails or computer time. If that doesn’t do the trick, try changing up your sleep schedule so you go to bed later, when you actually feel tired.

Insomnia and normal sleeper groups were recruited from January to July, 2004 via flyers posted around the city and referrals from primary care physicians. Of the 208 individuals who responded to advertisements, 152 did not take part due to falling outside the inclusion criteria (n = 30), (n = 6), difficulty with the English language (n = 4), insufficient time (n = 48), sleep disturbance being attributable to a medical or psychological problem (n = 7), and not able to be contacted (n = 57). 

Second, other studies have investigated the association between sleep quality and the subjective perception of sleep parameters. The results suggest that sleep quality is associated with subjective estimates of the ease of sleep onset, sleep maintenance, total sleep time and early awakening. In addition, restlessness during the night, movement during sleep and anxiety, tension, or calmness when trying to sleep have also been reported to be associated with sleep quality. Moreover, perceived depth of sleep is important with less perceived light sleep and more perceived deep sleep being associated with higher sleep quality.

“Sleep is a cornerstone of weight management because of the impact it has on your hormones that control how you burn fat, how you store fat, and how you’re maintaining muscle. The better your hormone balance, the better your weight management. —Jillian Michaels, The Biggest Loser Trainer