Sleep experts are talking about the so-called “second wind” that can sabotage nights and push people awake in the middle of the night, and this piece walks through why timing matters and what to try instead. The focus is on how cortisol and melatonin interact, the practical bedtime window one naturopath recommends, and the confirmations and tips offered by a sleep physician. Readable, direct advice is paired with verbatim expert quotes to keep the science clear and actionable.
On social video, Ontario naturopath Kara Petrunick lays out a simple warning about late bedtimes and hormones. “If you go to bed between 11 p.m. and 1 a.m., you are doing a disservice to your hormones,” she said. That short statement is the jumping off point for a wider claim about how nights derail when sleep timing slips.
Petrunick frames the issue around two key hormones that govern sleep and wakefulness. “In the evening, cortisol should be at its absolute lowest, because it needs to allow melatonin to be at its highest to put you in a deep, restorative sleep. Cortisol and melatonin work opposite each other.” When those signals don’t line up, falling and staying asleep can become a problem.
She points to a late-night cortisol spike as the culprit that triggers awakenings and hunger in the night. “This spike will also cause a bout of hypoglycemia in the middle of the night, forcing you to wake up a few hours later,” she said. “So, the optimal time to go to bed is 10:30, to prevent the second spike.” She also recommends waking up around 6:30 a.m.
Dr. William Lu, a medical director at a California sleep company, confirms the phenomenon and frames it in physiology rather than willpower. “The ‘second wind’ happens when your body’s circadian rhythm and homeostatic sleep pressure are out of sync,” he told Fox News Digital. That mismatch can create a temporary boost in alertness even when you were tired earlier.
Lu explains the mechanics of that alertness surge in plain terms and connects it to everyday habits. “Even if you feel tired earlier in the evening, your body can temporarily become alert due to a natural surge in cortisol and core body temperature, often a few hours before your usual bedtime.” People who keep irregular hours or habitually stay up late are the ones most likely to notice this pattern.
Both experts land on routine as the most reliable fix: go to bed and wake at roughly the same times every day and stop feeding late-night alertness. Avoiding late caffeine, heavy meals and intense exercise too close to bed gives the body fewer reasons to spike hormones and stay wired. The idea is to let melatonin do its job without cortisol pushing back.
Lighting and screens also get called out because of their strong influence on internal timing. Dim the lights and limit screen exposure in the hour or so before bed, since bright light suppresses melatonin and can nudge your clock later. Adding a consistent wind-down practice like reading, meditation or gentle stretching helps link the end of the day with actual sleep readiness.
Lu sums up how to match behavior to biology with a focus on timing that supports deep sleep rather than fighting it. “The best time to go to bed to avoid the second wind is one that matches your body’s melatonin surge, promoting faster sleep onset,” he said. “This avoids the late-night alertness spike … and supports restorative deep sleep in the first half of the night, [which is] critical for cardiovascular, metabolic and cognitive health.”
