The Importance of Sleep Regularity

Scientists and researchers are learning more about the critical role sleep plays in our health, but getting that information to the public is challenging. Here’s an example: in 2023, the National Sleep Foundation assembled an expert panel of 12 sleep and body clock scientists from major universities and hospitals (Harvard, Oxford, Monash, UT Southwestern, Northwestern, and others). The panel reviewed 63 studies on the effects of regular and irregular sleep schedules on health, mood, and performance.

• They focused on two big questions:

  • Is keeping a regular bedtime and wake time important for health and performance?

  • If you do not get enough sleep on workdays, is sleeping longer on weekends or days off helpful?

They published their results in the journal Sleep Health. Here’s what they concluded:

1. Regular sleep times matter

• People whose bedtimes and wake times jumped around a lot from day to day tended to have worse health and performance than people with more regular sleep.​

• Across 54 studies, increased “sleep timing variability” (irregular sleep) was linked to:

  • Higher risk of heart and blood vessel problems, including cardiovascular disease.

  • More metabolic problems, such as higher blood sugar, more body fat, and higher chances of metabolic syndrome and diabetes

  • More inflammation in the body, which is related to many chronic diseases.

  • Worse mood, more depression, more stress, and even higher suicidal thoughts in some groups.

  • Poorer thinking and attention, lower academic performance, and worse daily functioning.

2. Irregular sleep was not good in any study

• Among all the studies reviewed, irregular sleep was either neutral or harmful; none showed that irregular sleep was good for health or performance

• In some long‑term studies, each extra hour of fluctuation in sleep timing was linked to notably higher risk of metabolic syndrome and heart events.

3. Catch‑up sleep can help if you are short on sleep

• Many adults (including seniors) get less sleep than they need on workdays or busy days.

• In people who slept too little during the week, getting 1–2 extra hours of sleep on weekends or days off (“catch‑up sleep”) was linked to:

  • Lower risk of metabolic syndrome.​

  • Better markers of inflammation (for example, lower high‑sensitivity C‑reactive protein in those who usually slept 6 hours or less

  • No extra risk of death compared with people who regularly slept enough, while people who stayed short on sleep every day had a higher risk of death.

4. But catch‑up sleep is not perfect

• Catch‑up sleep does not fully erase the harm of chronic sleep loss; it may take several days to recover even from one hour of missed sleep each day.

• Sleeping late on days off can delay your internal body clock, making it harder to wake up early again on the next workday or appointment day.

5. Support your body clock

• Get morning daylight (even 15–30 minutes walking or sitting near a bright window) at about the same time every day to help keep your internal clock steady.

• Keep the evening calm and dim: lower lights, avoid bright screens right before bed, and follow a relaxing routine (reading, gentle stretching, or quiet music).

6. Work with your health team

• If you have trouble falling or staying asleep, or if you feel very sleepy in the daytime, talk with your doctor, especially if you have heart disease, diabetes, mood problems, or memory concerns; these conditions are closely linked to sleep health in older adults.

• Ask your doctor or a sleep specialist how to:

  • Safely regularize your sleep schedule if you are on medications that make you drowsy.

  • Screen for sleep disorders such as sleep apnea or restless legs, which can disrupt sleep even when your schedule is regular.