In their self-titled debut album, Arcade Fire, the 2103 Grammy winner for best album, sings "Sleeping is giving in."

It's a perfectly logical lyric because it succinctly summarizes the way many super-busy and super-successful people view anything more than the absolute minimum amount of sleep. To them, eight hours of sleep isn't really a necessity. It's an indulgence, a luxury, something you might allow yourself on a Sunday after the work week is done.You could even say that sort of a view is part of the American mindset, a part that probably helped make the country great yet a part that needs to change.I write that in part because of a recent Penn Medicine study published in the March issue of Neuroscience. It suggests that sleeping is not "giving in" or a luxury. In fact, this study suggests that if you see a weekday lack of sleep as something you make up for after the work week is done, you can be doing yourself physical harm.Sigrid Veasey, MD, associate professor of Medicine and a member of the Center for Sleep and Circadian Neurobiology at the Perelman School of Medicine at Penn along with researchers at Peking University showed that those who continually shortchange themselves sleep are probably killing brain cells.The study used mice to replicate chronic sleep loss in humans and found that the cause for the poor mental performance that often results from a lack of sleep comes from more than mental weariness. In the mice studied, neurons were far more likely to be injured during short-term sleep loss from extended wakefulness and these injuries created cell death, up to 25 percent more than those mice sleeping regularly.That's why chronic sleep loss could quite possibly kill brain cells in humans.When Veasey adds his research to prior human studies that have found elements like attention span do not normalize after sleep-deprived subjects have three days of recovery sleep, this cell-death-from-sleep-deficiency theory makes even more sense.But the Penn Medicine study isn't the only recent one linking poor health to a lack of sleep. Research performed in England and published in the International Journal of Obesity found 16-month-old children who sleep significantly less than what's optimal eat significantly more than what's normal at 21 months old.The age of the subjects seems particularly important. At such a young age, the subjects have not yet started eating for social reasons.The number of calories they consume a day should represent nothing more than need. And why those who slept less than 10 hours each night at 16 months old five months later need more calories than those who slept more than 13 is hypothesized to be the same reason why adults deficient in sleep eat more.Sleep deficiency seems to adversely affect the hormones in the body that help regulate appetite.In the aforementioned study, those getting significantly less-than-optimal sleep ate on average 105 more calories a day. Ironically, this number is virtually the same as the "extra 100" often written about that seemingly makes average-weight young adults overweight by early middle age.Now if your lack of sleep stems not from dismissing its importance but from your inability to achieve it, consider the results of the National Sleep Foundation's 2013 Sleep in America poll. In it, a correlation emerges between regular exercise and sufficient sleep, with more intense exercise proving to be better at achieving the latter.Strangely enough, both those reporting themselves to be non-exercisers and exercisers slept on average the same amount of time: six hours and 51 minutes. What differed dramatically, however, was the quality of the sleep.Only 39 percent of non-exercisers responded positively when asked if they get a good night's sleep "almost every night on work nights," yet 67 percent of exercisers responded that way. More importantly, "vigorous" exercisers those reporting as least 10 minutes of hard physical effort in the last seven days had far fewer sleep-related problems than non-exercisers.While 50 percent of non-exercisers reported waking up frequently during the night, less than 33 percent of vigorous exercisers claimed the same. While 24 percent of non-exercisers reported difficulty falling asleep "close to every night," 72 percent of vigorous exercisers reported "no trouble" falling to sleep and 69 percent claimed to have no problem falling back to sleep after waking for whatever reason.A final reason for those who find sleep illusive to muster the motivation to exercise comes from Max Hirshkowitz, PhD, and the chairperson of the NSF poll. He believes sufficient sleep does not cause you to want to exercise or exercise more, but rather the opposite: that exercising even on a day you're dragging from a lack of sleep makes it more likely that you'll get a good night's sleep that night.