The 4 Season Solution. Dallas Hartwig

mental, and social health, sleep is a key foundational element. In many cases, sleep eclipses food in importance. So, I hereby correct myself: optimal health really does start with sleep and the inherent rhythmicity that it is (or should be) built on.

      Our National Sleep Recession

      I remember being approached by a woman in her late twenties after a seminar a few years ago. Let’s call her Jill. She loved high-intensity interval training (HIIT) workouts, which involve short spurts of highly strenuous activity like sprinting, heavy lifting, or kettlebell routines. Research suggests that such workouts build lean muscle mass, increase metabolism, and are more efficient at improving fitness than working out at lower intensities for longer periods of time.¹ Jill’s enthusiasm for HIIT training was apparent—she did these strenuous workouts multiple times a day, six days a week. She was largely following a Whole30/Paleo diet, avoiding processed foods, artificial sugars, and grains, instead emphasizing healthy vegetables and complete protein sources. From her quick overview, however, it was clear to me that she was likely restricting her food intake too much.

      Here’s what was baffling about Jill. At a superficial glance, she was a lean, muscular woman. Many of her friends and passersby on the street admired her body, and used words like “badass” and “hardcore” to describe her. “Wow, you are so lean and cut,” people would fawn, “you inspire me to get off my rear and work out more.” But appearances were deceiving. When you took a closer look at Jill, she came off as tired, in the manner of someone who’s just pulled an all-nighter. Powered by caffeine and sugar, and deprived of sleep, most people who’ve stayed up look a little rough and haggard. They have bags under their eyes and a subtle slump in their shoulders. Jill certainly looked that way. Her skin also bore many hallmarks of someone who engaged in excessive amounts of high-intensity exercise. It was graying a bit and becoming prematurely wrinkled. I’d seen this a lot in my endurance training clients. The chronic stress of such intense workouts leads to ongoing cortisol release throughout the system, causing structural breakdown in things like collagen that keep our face and skin looking youthful and healthy.

      Like many competitive athletes I’d seen, Jill was prematurely aging herself. And not just superficially. Her hormones had become unbalanced and her menstrual cycle was irregular, which meant she had severe PMS symptoms that could have led to infertility. She also didn’t feel good on a day-to-day basis and relied on stimulants to power through those long afternoons at work. Hardly the picture of optimal health.

      When I asked her about her sleep, she seemed baffled: “What has that got to do with anything?” To get to her morning workout, she was rising before sunrise. She then returned to the gym during some of her lunch breaks, when she could get away, or in the evening. By the time she had finished and driven home and fixed a meal, it was already bedtime. Or it should have been. Jill had trouble falling asleep, and for good reason. Her intense workouts ramped up cortisol levels, putting her into a fight-or-flight state. From an evolutionary standpoint, such a state of readiness, hypervigilance, and stimulation was a perfect response when we needed to fend off hostile predators on the savannah, to run or fight for our lives. But it certainly isn’t optimal for a body preparing for sleep, and it prevented Jill from sleeping as much or as well as she might have.

      Even when confronted with these facts, Jill didn’t want to talk about her sleep or caffeine consumption. She wanted to know how much lower she should take her carbohydrate intake because she was struggling to move some stubborn belly fat. This is again something I’d noticed among distance runners and triathletes (and other recreational athletes): their arms and legs are muscular, sinewy, and fairly lean. But if you look closely, they often have a little pouch around their middle, a classic hallmark of excess cortisol release over long periods of time. Jill was sure she needed a dietary fix because at ten to twelve workouts per week, she simply couldn’t fit in any more training. Following her evening high-intensity training, she would often need a couple of hours to unwind, which she would spend under bright lights at home, either watching TV, surfing the web on her laptop, messaging friends on her phone, or, more typically, all the above in turn.

      She was layering stimulation on top of stimulation—news of her friends, the dopamine surges from smartphone notifications, the melatonin-reducing blue light from the Netflix show she streamed on her tablet. She would, eventually, drag herself off to bed, or fall asleep among her humming devices, collapsing more from sheer exhaustion than restful repose. Feeling tired but wired, it would generally be some time around midnight before she was falling into what she described as a relatively light sleep, with her alarm set for 5:00 a.m., ready to start it all over again.

      I wish I could say this was a rare and extreme example. But such stories are more common than you might think. The exact details vary—sometimes the story doesn’t involve getting up so early for exercise, but for a daily commute. Still, the overarching pattern is generally the same. Modern civilization is suffering through a massive sleep recession, with the CDC reporting that over one-third of US citizens get less sleep than the recommended seven hours each night.² In the early twentieth century, this wasn’t the case. Americans logged around nine hours.³ But along came artificial light, revolutionizing our economies and our sleep routines. Following the introduction and eventual ubiquity of the light bulb in the twentieth century and the rise of individual LCD screens throughout the twenty-first, our sleep has steadily declined.⁴ Now, we get up early and stay up late in a world that stays lit 24/7. The ethos of the city that never sleeps has spread to the entire modern world.

      Many of us offer up similar reasons for burning the LEDs at both ends of the day. There are not enough hours in the day to do all the things we want or need to do. There’s the daily commute, becoming ever greater as we choose to live farther away from our workplaces or are forced to for economic reasons, such as affordability of housing. Early in the morning or late at night might be the only space we get for me time, away from work or our often overstimulated kids. Our days and our time are so overscheduled that the moment anything extra falls in our lap, we need to borrow (read: steal) time from sleep. We routinely treat our sleep like a credit card in that we feel like we have money to spend, but in reality are barely keeping up the minimum payments.

      Is it really that bad, though? After all, recent evidence challenges the notion that our preindustrial ancestral cousins slept more than we postmodern humans do, and that we should be sleeping from sundown to sunup because that’s how Paleo man slept. UCLA researchers followed the sleep habits of three contemporary nonindustrial societies.⁵ Studying the few remaining societies that live without access to electric light, they reasoned, may illuminate current sleep trends. Absent artificial light and digital technologies, do we sleep longer and better?

      At first blush, the research appeared to indicate that these populations spent much more time sleeping than most people living in modern society—seven to eight and a half hours each night. However, further analysis of the data collected revealed that of this time in bed, only five and a half to seven hours was actually spent asleep. This is roughly comparable to modern postindustrial societies.⁶

      This research generated many commentaries and interpretations, the most obvious being that we can all relax—that midnight to 5:30 a.m. sleep routine you have is in fact perfectly normal. “The argument has always been that modern life has reduced our sleep time below the amount our ancestors got, but our data indicates that this is a myth,” said Jerome Siegel, leader of the research team and professor of psychiatry at UCLA’s Semel Institute of Neuroscience and Human Behavior.⁷ “I feel a lot less insecure about my own sleep habits after having found the trends we see here,” echoed lead author Gandhi Yetish, a PhD candidate at the University of New Mexico.⁸

      I can’t quite embrace that conclusion. The sleep patterns of these tribes seem to work well for them, but based on my work with hundreds of consulting clients, that same amount of sleep doesn’t seem to support healthy outcomes in different, more stressful environments. We industrialized humans burn the metaphorical candle at both ends… with a blowtorch. In the same way that doing a lot of intense exercise requires more nutritious food for full recovery, living a modern life of stress and overstimulation might require more sleep than if we were living like our electricity-free counterparts. Sleep of closer to