During the early months of the pandemic, something happened to ER nurses that most people never saw.
Not the part that made the news. Not the exhaustion on the surface. Anyone could see that.
It was what happened when they got home.
I was working at a local university at the school of nursing at the time. The students weren’t just learning. Many were already working shifts. And the stories that were shared were consistent enough that I couldn’t ignore them.
These weren’t people who had never handled pressure before. They were trained for it. But nothing had prepared them for what sustained, unrelenting crisis mode does to a body that never gets the signal to complete the stress cycle.
The problem was that their bodies had learned to stay on high alert because the job demanded it, shift after shift, for months without a break in the pace.
Picture this. A female nurse in her early thirties. Twelve-hour shift and sometimes more in an ER that didn’t slow down in 2020. Triaging. Making fast decisions. Staying present for patients who were frightened and deteriorating. She wasn’t stressed in the way that word usually gets used. She was in a hyper-aroused state. Precisely, efficiently, necessarily on high alert. The job required nothing less.
She would get home and be alone.
Still in her scrubs, she sits on the couch because changing feels like one more thing, and she has nothing left for one more thing.
There was a routine. A glass of wine. Something on TV. A bath. They feel like relief, briefly.
Then she lies down.
Her chest is still tight. Her mind is still in the ER. She’s already running through tomorrow’s shift. She watches the clock move from midnight to 1am to 2am.
She’s back on at 6am.
This wasn’t one nurse. Studies from the first wave of the pandemic found that more than 80% of frontline nurses reported poor sleep quality, and nearly two-thirds screened positive for burnout and depression. Longer irregular hours and disrupted routines overwhelmed the recovery systems these nurses had relied on. See the NIH Literature here.
But here’s what those numbers couldn’t fully capture, and what nobody was telling these nurses at the time:
The exhaustion wasn’t the problem. The inability to move through the stress cycle was.
Stress is a physiological cycle with a beginning, middle and end. The body is designed to complete it. Most of what we do interrupts that cycle before it finishes.
Her body had spent months learning that hyper-arousal was the correct response to her environment. It was right. It kept her sharp when her patients needed her to be.
But no one had given her the tool to tell her body the threat was over.
The nervous system needs a cue.
And she didn’t have one.
What Exhaustion Without Recovery Actually Feels Like
Her story wasn’t unusual. And if you’ve ever lain awake exhausted and wired, it probably sounds familiar.
Most people assume that being tired enough will eventually override everything else. That at some point, the body just shuts down and sleeps.
That’s not always how it works.
When your nervous system has been in hyper-arousal for hours — genuinely required — it doesn’t switch off the moment you sit down. Your brain is still scanning. Still processing. Still running the patterns it spent all day reinforcing.
Your body kept you sharp when the job needed it. And it’s still going.
So you lie there, physically depleted, and your mind won’t stop. Conversations replay. You’re running through the next shift.
This isn’t insomnia in the traditional sense. It’s a nervous system that hasn’t received the signal to move out of hyper-arousal.
The Part Nobody Explains About Sleep
Sleep doesn’t start when your head hits the pillow.
It starts hours before — in the signals your body is either receiving or not receiving throughout the day.
Here’s the physiology. When you breathe too fast, too shallow, or through your mouth, which most people do without realizing it, carbon dioxide levels drop. CO2 is what signals your red blood cells to release oxygen to your tissues. Less CO2 means less oxygen reaching the places that need it.
The body reads this as a stress signal. It stays alert. The internal chemistry to support rest and restore hasn’t kicked in.
Patrick McKeown, author of The Oxygen Advantage, calls this chronic over breathing. In my work, it’s the pattern I see the most.
The breathing pattern you carried through your shift doesn’t automatically reset at 11pm. If you spent hours breathing in a way that kept your nervous system activated, your body is going to carry some of that into sleep.
The transition has to be created. Breath is how you create it.
What This Looked Like for People in High-Demand Roles
This pattern isn’t unique to healthcare. You may recognize it.
Exhausted but wired. Too tired to function, too activated to rest. Reaching for wine, screens, anything that felt like an off switch. Getting a few hours of shallow sleep and waking up feeling like sleep never came.
The problem wasn’t their routine. It was that nobody talked to them about how to change the internal signal.
Relief and recovery are not the same thing. A glass of wine creates the feeling of relaxation. It doesn’t change your CO2 levels, slow your breathing pattern, or give your nervous system the physiological message that the threat is over.
The Signal Your Body Needs Before Sleep
The nervous system is responsive to breath in a very direct way.
When you slow your breathing down — specifically when you extend your exhale and breathe through your nose — CO2 levels stabilize and oxygen delivery to your tissues improves. Slow nasal breathing with an extended exhale also directly stimulates the vagus nerve. That’s the pathway that shifts your body from activation into rest and restoration.
This isn’t a relaxation technique. It’s a physiological input.
For someone who has spent hours in a high-activation state, this matters more than almost any other wind-down habit. Not because it forces sleep, but because it gives the nervous system accurate information.
The day is over.
A Simple Practice to Try
Try five minutes of slow nasal breathing with an extended exhale.
Sit or lie down. Close your mouth. Breathe in slowly through your nose for four counts. Breathe out slowly through your nose or through your mouth as if you’re blowing through a straw for six counts. Let the exhale be easy, not forced.
That’s it.
You’re giving your nervous system new information. Over time, with repetition, that information starts to build. The transition into rest can become easier to access during hard days.
The Bottom Line
If you’re exhausted but can’t sleep, your body is still activated.
The good news is that breath is a direct line to the signal your body is seeking to complete the stress cycle. Try five minutes of slow nasal breathing to tell your nervous system the threat has passed.
That’s where recovery begins. The earlier in the day you send that signal, the less your body has to unwind before sleep.
If you’re curious about what it looks like to build this kind of recovery into a demanding day the Breathe & Refuel program is built around exactly that. You can learn more [here].
