08/09/2022 | News release | Archived content
Whether you're just getting home from a night on the town or you simply got a jolt of energy winding down on the sofa, few things are more frustrating than your body giving you a sudden burst of energy right when you're winding down to drift off. This irksome occurrence is known as catching a second wind.
"A second wind refers to the phenomenon when a person stays awake longer than their usual bedtime, causing a temporary boost in alertness," says Wendy Troxel, Ph.D., author of "Sharing the Covers: Every Couple's Guide to Better Sleep." You essentially miss your body's ideal or familiar sleep window," she explains, "which makes it very difficult to fall asleep, even after extended periods of wakefulness."
If you regularly stay up past your bedtime, whether planned or not, you may be pretty used to second winds by now. One way to turn things around is to better familiarize yourself with your body's wake maintenance zone (more on that in a moment). Getting to know this aspect of how your body functions can help you become one with your circadian rhythm and get the full night's sleep you need to function at your best.
The master clock in our brain that coordinates our body's various biological rhythms, including our sleep or wake cycle, is called the suprachiasmatic nucleus, or SCN. It's a control panel influenced by diet, exercise, habits, hormones, and light. Changes in light in our environment are processed by our eyes, which send direct messages to our master clock, which sets our cycles of alertness and sleepiness.
When there's more light - cue sunrise - the brain sends an alert that it's time for the body to produce more cortisol, a hormone that's best known for its role in biological stress response, but is also a key player in stimulating wakefulness, especially first thing in the morning.
Our cortisol levels are highest when we wake up, then gradually decline throughout the day. They hit their lowest levels right around bedtime - just as your eyes are reporting to your SCN that it's getting dark, and time to amp up melatonin production, resulting in feelings of sleepiness.
As your circadian rhythm is doing its thing, so is your homeostatic sleep drive: "The longer you've been awake, the more your sleep drive increases," Troxel says. "This is indicated by the buildup of a chemical in the brain called adenosine."
Adenosine accumulates in the brain during wakefulness, eventually inducing physiological sleep. While you're snoozing, the brain washes away the adenosine buildup so that come morning, cortisol levels can do their thing, helping you feel refreshed and ready to rock.
Of course, life has a way of going awry and sending your sleep/wake cycle off the rails. This is where bonding with your wake maintenance zone can really come in handy.
"The WMZ refers to the fact that in the early evening hours, just prior to the release of melatonin, the circadian drive for sleep is actually very low - serving to maintain wakefulness at a time when sleep drive is quite high," Troxel says.
It might seem counterintuitive for this to happen just as it's time to unwind, she adds, but the WMZ keeps you awake in the early evening to enhance the likelihood of obtaining roughly 16 hours of extended wakefulness during the daytime and eight hours of consolidated sleep at night.
However, sometimes life interrupts our biological rhythm and sleep cues, whether from stress elevating cortisol levels, screens suppressing melatonin production, or activities giving us social jetlag. When that happens, our bodies end up receiving instructions to stay awake instead of climb into bed, which brings on the second wind.
"A second wind is usually caused by a flux of dopamine in the brain," says Nicole Avena, Ph.D., associate professor of neuroscience at Mount Sinai School of Medicine in New York. "Dopamine counteracts the sleep-enacting hormone adenosine, keeping you awake for longer."
Dopamine preventing sleep can be triggered by multiple things, including:
Revenge bedtime procrastination, or the tendency to delay your wind-down routine even if you know you're ready for bed, has also become a prominent reason why people miss their sleep window and experience a second wind.
According to the CDC, the circadian clock is most sensitive to light about two hours before your usual bedtime, so keeping lights on past this point could amplify your second wind. To encourage your body to feel sleepy:
Troxel recommends families set up a central charging station where everyone retires their phones at night, so that phones aren't in bedrooms. "Your phone can recharge overnight, just as your body can recharge with sleep," she says.
Some examples of simple snacks that are packed with magnesium include:
"Sugar gives us energy - and that's the opposite of what we need to fall asleep - so avoid nuts that are honey-roasted or caramelized, as well as high-sugar oat bars or yogurts," Avena says.
Avena recommends 4-7-8 breathing: Breathe in for four seconds, hold your breath for seven seconds and breathe out through your mouth for eight seconds. Repeat for three to four rounds at a time.
When you finally do feel sleepy again, that's your cue to go to bed. "It will take as long as it takes and the less you stress about it, the sooner sleep will come," Troxel says.
"To avoid the night 'slipping away' and a second wind kicking in, set an alarm for bedtime too," Troxel says. "The bedtime alarm should be set at least an hour before your desired bedtime as a signal that it's time to start winding down and avoiding activities that are too stimulating." Think: work, exercise, heavy convos, doomscrolling.