Most of us know that we need a bit more sleep than we are getting. We push through the work week and then catch a few extra hours of sleep on the weekends without considering the long term effects this might be having on things like how long we live.
If you decide to make a lifestyle change and regularly get more sleep, you will have to re-prioritize activities with friends and family and even set new time boundaries at work. This is hard to do because you will be fighting a strong cultural influence that labels sleep-prioritizers as unproductive and lazy. There will be pressure from people who say things like “I will sleep when I am dead” and from people who believe statements like this one posted along a risky roadway in British Columbia:
Knowing how much sleep to aim for is also difficult. There are lots of anecdotes from vocal, and successful, people saying they sleep very little while there are relatively few prominent people announcing that they prioritize sleep above all else. Who is giving the best advice?
The quiet sleep-prioritizers are much closer to what sleep science prescribes when it comes to long term outcomes like how long you live. One of the most famous sleep researchers in the world, Dr. Torbjörn Åkerstedt and his research group, recently published a study using data from over 43,000 people.They found that for people younger than 65, regularly sleeping five hours or less or eight hours or more increased the risk of dying[1] compared to people who regularly slept six to seven hours everyday. The increased mortality rates in this study are consistent with previous large scale studies such as one from 2002 that used data from 1.1 million people ranging in age from 30 to 102. This study found that the best survival rate was for those who slept seven hours per night[2].
Sleeping seven hours everyday will keep you alive longer according to these two studies. But sleeping seven to nine hours will keep you performing better than sleeping less [3]. In other words, don’t believe the successful people who say you need to sleep less.
But what about catching up on sleep on the weekend to make up for missing weekday sleep? From a life expectancy standpoint, this seems to be Ok[1], you won’t shorten your life by sleeping a little less than seven hours during the week and then making up for it on the weekend. However, from a performance standpoint, your performance will suffer if you drop your sleep to less than six hours for a couple of nights[4].
The best advice, from science, is to try to get at least seven hours of sleep everyday with a few days of seven to nine hours of sleep for good measure. If you can’t match this pattern, then get at least six hours of sleep every day and sleep more on weekends.
References
[1] Åkerstedt, T., Ghilotti, F., Grotta, A., Zhao, H., Adami, H., Trolle-Lagerros, Y., & Bellocco, R. (2019). Sleep duration and mortality – Does weekend sleep matter? Journal of Sleep Research, 28, e12712.
[2] Kripke, D., Garfinkel, L., Wingard, D., Klauber, M., & Marler, M. (2002). Mortality associated with sleep duration and insomnia. Archives of General Psychiatry, 59, 131-136.
[3] Hirshkowitz, M., Whiton, K., Albert, S., Alessi, C., Bruni, O., DonCarlos, L., Hazen, N., Herman, J., Katz., E., Kheirandish-Gozal, L., Neubauer, D., O’Donnell, A., Ohayon, M., Peever, J., Rawding, R., Sachdeva, R., Setters, B., Vitiello, M., Ware, J., Hillard, P. (2015). National Sleep Foundation’s sleep time duration recommendations: Methodology and results summary. Sleep Health, 1, 40-43. For a summary of the recommendations see: https://www.sleepfoundation.org/press-release/national-sleep-foundation-recommends-new-sleep-times
[4] Dawson, D., & McCulloch, K. (2005). Managing fatigue: It’s about sleep. Sleep Medicine Reviews, 9, 365-380.