1 00:00:02,040 --> 00:00:07,080 Speaker 1: Welcome to brain Stuff from How Stuff Works, Hey, brain Stuff, 2 00:00:07,120 --> 00:00:10,559 Speaker 1: Lauren Vogelbaum. Here good news for people who use their 3 00:00:10,640 --> 00:00:13,720 Speaker 1: days off as they are intended to rest up after 4 00:00:13,800 --> 00:00:17,320 Speaker 1: a busy week. It turns out those compensatory zas are 5 00:00:17,440 --> 00:00:21,040 Speaker 1: far more beneficial than previously thought, according to a Swedish 6 00:00:21,079 --> 00:00:24,239 Speaker 1: study published in in April issue of the Journal of 7 00:00:24,280 --> 00:00:27,360 Speaker 1: Sleep Research. The study looked at more than forty three 8 00:00:27,400 --> 00:00:31,040 Speaker 1: thousand people who participated in the Swedish National March cohort, 9 00:00:31,200 --> 00:00:35,760 Speaker 1: which began in follow up for every subject continued until 10 00:00:35,800 --> 00:00:40,839 Speaker 1: they died, moved away, or December, when the study officially closed. 11 00:00:41,560 --> 00:00:44,440 Speaker 1: The researchers for the sleep study pulled relevant data from 12 00:00:44,440 --> 00:00:47,800 Speaker 1: the cohort questionnaire about basic sleep habits, like how many 13 00:00:47,840 --> 00:00:51,199 Speaker 1: hours approximately participants sleep on a workday night, as well 14 00:00:51,240 --> 00:00:53,600 Speaker 1: as how many hours they snooze per night on days 15 00:00:53,640 --> 00:00:57,000 Speaker 1: off of work. Response increments ranged from less than five 16 00:00:57,040 --> 00:01:00,760 Speaker 1: hours to greater than nine hours. Previous studies have shown 17 00:01:00,800 --> 00:01:04,160 Speaker 1: that people who consistently sleep too little short sleep is 18 00:01:04,160 --> 00:01:06,800 Speaker 1: defined as five hours or less a night, or too 19 00:01:06,880 --> 00:01:09,920 Speaker 1: much long sleep is nine or more hours per night, 20 00:01:10,280 --> 00:01:13,080 Speaker 1: have higher mortality rates than people who fall into the 21 00:01:13,080 --> 00:01:16,560 Speaker 1: Goldilocks zone in between getting just the right amount of 22 00:01:16,600 --> 00:01:20,160 Speaker 1: sleep every night. However, the authors of the study point 23 00:01:20,200 --> 00:01:22,720 Speaker 1: out that few, if any, of those studies have asked 24 00:01:22,720 --> 00:01:26,839 Speaker 1: participants to differentiate between week day and weekend sleep, which 25 00:01:26,920 --> 00:01:30,000 Speaker 1: makes a big difference, they wrote, in the current study, 26 00:01:30,360 --> 00:01:33,400 Speaker 1: because there are five week days and two weekend days, 27 00:01:33,680 --> 00:01:36,400 Speaker 1: it is likely that self reports of typical sleep duration 28 00:01:36,560 --> 00:01:40,400 Speaker 1: more strongly reflect weekday sleep. Thus, it is of interest 29 00:01:40,480 --> 00:01:44,520 Speaker 1: to investigate the relationship between weekend sleep duration and mortality, 30 00:01:44,800 --> 00:01:47,600 Speaker 1: as well as the different patterns of sleep duration between 31 00:01:47,720 --> 00:01:51,840 Speaker 1: week day and weekend sleep. When the researchers looked at 32 00:01:51,880 --> 00:01:55,240 Speaker 1: all of the data, findings were consistent with previous conclusions 33 00:01:55,360 --> 00:01:58,600 Speaker 1: of increased mortality if both week day and weekend sleep 34 00:01:58,640 --> 00:02:02,279 Speaker 1: are short or when both are long. However, they wrote, 35 00:02:02,600 --> 00:02:06,320 Speaker 1: when weekend sleep is extended after short weekday sleep, no 36 00:02:06,400 --> 00:02:10,000 Speaker 1: association with mortality is seen. We suggest that this may 37 00:02:10,040 --> 00:02:15,280 Speaker 1: reflect positive effects of compensatory sleep. Experts have long advised 38 00:02:15,320 --> 00:02:17,400 Speaker 1: people to get up at the same time each day, 39 00:02:17,560 --> 00:02:20,639 Speaker 1: even on weekends, as a long term strategy for getting 40 00:02:20,680 --> 00:02:23,920 Speaker 1: better sleep each night. The theory is that yo yoing 41 00:02:24,000 --> 00:02:28,360 Speaker 1: sleep habits disturb your circadian rhythms. Dr David Ding's was 42 00:02:28,480 --> 00:02:30,840 Speaker 1: not involved in this sleep study, but he's the chief 43 00:02:30,880 --> 00:02:33,720 Speaker 1: of the Division of Sleep in Chronobiology at the University 44 00:02:33,760 --> 00:02:37,720 Speaker 1: of Pennsylvania Perlman School of Medicine. He told Time Magazine, 45 00:02:38,160 --> 00:02:40,560 Speaker 1: the real question is whether there is in fact a 46 00:02:40,600 --> 00:02:43,800 Speaker 1: build up of deficit or biological changes that are gradual 47 00:02:43,880 --> 00:02:48,000 Speaker 1: over time, even though you get recovery sleep. So while 48 00:02:48,040 --> 00:02:50,160 Speaker 1: this study is great news for those of us who 49 00:02:50,200 --> 00:02:53,320 Speaker 1: like to sleep in on days off, many sleep experts 50 00:02:53,360 --> 00:02:55,639 Speaker 1: say more studies need to be done on this subject. 51 00:03:00,800 --> 00:03:03,440 Speaker 1: Today's episode was written by Alia Hoyt and produced by 52 00:03:03,440 --> 00:03:05,880 Speaker 1: Tyler Clang. For more on this and lots of other 53 00:03:05,960 --> 00:03:08,960 Speaker 1: topics that may or may not reinforce your current habits, 54 00:03:09,120 --> 00:03:22,720 Speaker 1: visit our home planet, how stuff works dot com.