Sleep.
Sleep drives everything else: your recovery, your appetite, your mood, your progress in training. Here we answer the real questions (how many hours you need, how to get more deep sleep, when to stop caffeine, what to do when you wake at 3 a.m.) with straight answers, numbers from the research, and what you can change tonight.
Screens before bed: is blue light really bad for sleep?
Bright evening light does delay sleep, but the mental stimulation of screens matters just as much. What actually works for better nights, without gadgets.
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Caffeine and sleep: when to stop drinking coffee before bed
Caffeine has a half-life of 5 to 6 hours, so a 4 p.m. coffee lingers well into your evening. Why to cut it off 8 to 10 hours before bed, and what that changes.
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Deep sleep: how to get more of it
A cool bedroom, fixed sleep times, daytime exercise, an early caffeine cutoff: the levers that really boost deep sleep, and the ones that do nothing.
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How many hours of sleep do you really need?
7 to 9 hours for most adults, but the real answer depends on you. What the data actually says, and how to find your own sleep need in just two weeks.
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Everything the journal explains, the app tracks automatically, on your own data. The iOS beta is open to a small circle.
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