For two years, the alarm went off at 5 AM. Every single day. No easing into it. A few articles about how successful people wake up early, a reset alarm clock, and the experiment began. In Saigon, where the routine took shape, 5 AM is already warm and the streets are already alive with people exercising in the parks. It felt like joining something. It felt like discipline.
And for a while, it worked. Writing happened before anyone else was awake. Two hours of focus before a daughter was up and before calls with family back in Australia about the websites they run together. The output was impressive. What wasn't immediately obvious was the slow, steady deterioration happening underneath.
By month eight, afternoon crashes became routine. By month fourteen, an inexplicable irritability had set in. By month twenty, more was getting done than ever before — and almost none of it felt enjoyable. None of these things got connected to the alarm clock. They got connected to not trying hard enough.
It took longer than it should have to understand what was actually happening. This wasn't discipline being built. It was sleep being systematically shorted by sixty to ninety minutes a night, and the consequences were being rebranded as character development.
What Chronic Sleep Restriction Actually Does
The research on this is not ambiguous. A meta-analysis by Lim and Dinges examining the impact of sleep deprivation on cognitive performance found significant impairments across multiple domains, with the largest effects on sustained attention. Effect sizes ranged up to large magnitude, with lapses in simple attention showing the most severe decline. The deterioration wasn't limited to people pulling all-nighters. Even moderate, chronic restriction — the kind you get from shaving an hour or two off your sleep for weeks or months — produces cumulative deficits that compound over time.
A separate comprehensive review in Neuropsychiatric Disease and Treatment found that sleep deprivation impairs attention, working memory, long-term memory, and decision-making. The prefrontal cortex, responsible for executive function and impulse control, is particularly sensitive to sleep loss. The review noted that consistently restricting sleep over time is more harmful than a single night of total deprivation, because the deficits accumulate without the person being fully aware of how impaired they've become.
That last part is the trap. You don't feel yourself getting worse. You feel yourself getting used to it. You adapt to the diminished state and mistake the adaptation for normalcy. In this case, more words were being written and worse decisions were being made about what to write. The mornings started earlier and the thinking grew less clear once work actually began.
The Cortisol Problem Nobody Mentions
Beyond cognition, there's the hormonal impact. Research by Leproult, Copinschi, Buxton, and Van Cauter found that even partial sleep loss delayed the recovery of the HPA axis, the body's central stress-response system, from its early morning activation. After partial sleep deprivation, evening cortisol levels were 37% higher than normal. After total sleep deprivation, they were 45% higher. The researchers concluded that sleep loss may accelerate the development of metabolic and cognitive consequences of excess cortisol.
Cortisol follows a natural daily rhythm. It peaks shortly after waking and drops to its lowest point around midnight. When you chronically cut your sleep short, that rhythm gets disrupted. A review in the journal Sleep Science and Practice found that sleep restriction increases late afternoon and early evening cortisol levels, and that chronically elevated cortisol correlates with cardiovascular disease, obesity, metabolic syndrome, reduced bone mineral density, and impaired cognitive function.
A 5 AM wake-up framed as "winning the morning" was, in reality, prompting the body to run a low-grade stress response that never fully resolved before the next alarm went off.
The Belief System Behind the Alarm Clock
What kept the experiment going wasn't the results. By the second year, the results were clearly diminishing. What kept it going was a belief system that equated early rising with virtue and rest with weakness. A very specific cultural message had been internalized: that the people who succeed are the ones who sacrifice comfort, that sleep is a luxury the ambitious cannot afford, and that if you're not uncomfortable, you're not growing.
This belief system is everywhere. It's in the social media posts about 4 AM routines. It's in the entrepreneurial culture that treats exhaustion as a credential. It's in the quiet judgment directed at people who sleep in, as though their schedule says something about their character.
But the research doesn't support any of it. A review in Sleep Science examining the relationship between sleep, stress, and metabolism found that sleep deprivation is associated with hyperactivity of the HPA axis, impaired glucose tolerance, and neuroendocrine dysregulation. The researchers concluded that sleep, stress, and metabolism interact bidirectionally, and that dysfunction in one system cascades into the others. Good sleep isn't a luxury. It's a regulatory mechanism that keeps everything else running.
What the research supports is that sleep is not the enemy of productivity. Sleep is the infrastructure on which productive cognition depends. Cutting sleep to gain hours is like withdrawing from the bank faster than you deposit. You feel
