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Okay, I posted too soon about the sleep research, before I saw a couple of other interesting studies from the same conference (the 23rd Annual Meeting of the Associated Professional Sleep Societies).
First, an unexpected one from the Walter Reed Army Medical Center that found, contrary to expectations, that getting more exercise in a given day actually resulted in less sleep that night, and getting more sleep at night led to getting less exercise the next day. Very strange — but it sounds like the design of the study meant that they were looking more at correlations than cause-and-effect:
[Lead author] Dr. [Arn] Eliasson speculates that these findings may be explained by personality types: Individuals who are Type A (ambitious, active people during the day), may also be more hyper-vigilant at night and therefore sleep less; whereas people who are Type B (lower-key people who are less active) may have no difficulties falling or staying asleep. Another explanation may be that job and life stresses lead to busier days, more exertion and more calories burned but may interfere with sleep.
Second, an Australian study found that restricting sleep resulted in weight gain, even though the subjects were less hungry and ate less than when they were sleeping normally. More evidence, if any was needed, that missing sleep messes with the body and should be avoided.