Most people know the feeling of an adrenaline rush: your heart pounds, your breath quickens, and your focus narrows. That’s your fight-or-flight response, an ancient survival system that evolved to protect you from danger.
But while fight-or-flight was essential for escaping predators, modern life is full of triggers that can keep this stress switch stuck on. The result? Anxiety, fatigue, poor digestion, and nights where you feel wired but can’t fall asleep.
Here are five key reasons you might be living in fight-or-flight more often than you realise, and what you can do about your acute response to stress, like supplementing with Genius Sleep.
1. Constant Digital Stimulation
Every ping, buzz, and notification is a tiny jolt to your nervous system. Your brain evolved to respond to sudden signals in the environment as possible threats, the rustle of an animal in the grass, for example.
Today, that same mechanism reacts to your phone vibrating. With dozens or even hundreds of alerts daily, the brain interprets a constant stream of “threats” and keeps cortisol high. Add in blue light exposure at night, and the nervous system never gets the memo that it’s safe to rest.
Research shows that heavy smartphone use is associated with increased stress, reduced focus, and disrupted sleep. This doesn’t mean you need to ditch technology, but managing your digital load is essential.
Reset tip: Set boundaries with screens: schedule “notification-free” blocks during the day, and power down devices at least an hour before bed to improve your acute response to stress.
2. Unresolved Stress and Worry
Unlike a predator attack, which ends quickly, modern stressors are rarely short-lived. Financial pressures, work demands, or ongoing relationship conflicts create a steady stream of cortisol in your body's stress response system.
The fight-or-flight system wasn’t built for chronic activation. When stress lingers, the body stays in survival mode, impairing digestion, weakening immunity, and making it hard to relax.
Over time, you may stop noticing the tension because it feels normal, but your nervous system is still braced for danger. This “silent stress” often shows up in subtle ways: jaw clenching, shallow breathing, or difficulty winding down at night.
Reset tip: Externalise your stress. Journaling, talking with a trusted friend, or working with a therapist can help the body register that the danger is being addressed, not bottled up.
3. Poor Sleep Patterns
One of the clearest signs of a stuck fight-or-flight response is struggling with sleep. High evening cortisol disrupts melatonin production, making it harder to fall asleep. And even if you do nod off, the quality of rest is often shallow, with frequent waking because of acute response to stress.
Unfortunately, poor sleep worsens stress the next day, creating a cycle: stress prevents sleep, and lack of sleep makes stress responses stronger. Over time, this can lead to what scientists call “hyperarousal insomnia”, when the brain simply can’t downshift into rest.
Reset tip: Keep a consistent bedtime and wake-up time, even on weekends. Build a pre-sleep ritual that signals safety: dim lighting, gentle stretches, or calming tea.
4. Sedentary Lifestyle (or Over-Exercising)
Movement is one of the best ways to “burn off” the stress hormones released during fight-or-flight. But if you spend most of the day seated, those hormones linger in the bloodstream, keeping the stress cycle alive and worsening your acute response to stress.
On the flip side, pushing too hard with high-intensity exercise every day can also backfire. The body interprets overtraining as another form of stress, keeping cortisol levels high and recovery low. That’s why many athletes struggle with fatigue, poor sleep, and stalled progress when balance isn’t maintained.
Reset tip: Aim for balance. Gentle daily movement, like walking, stretching, yoga, helps shift the body into rest-and-digest. Layer in more intense workouts a few times a week, but give yourself recovery days.
5. Nutrient Depletion and Lifestyle Imbalance
Stress doesn’t just affect hormones, it also drains nutrients. Magnesium, B vitamins, and amino acids are burned through more quickly under pressure. Without these building blocks, your body struggles to calm the nervous system and produce neurotransmitters like serotonin and GABA, which promote relaxation.
At the same time, lifestyle imbalances, like too much caffeine, skipped meals, or chronic dehydration, keep the body in a heightened state of alert. Over time, nutrient depletion makes it harder to return to balance even when the stressor has passed.
Reset tip: Prioritise whole foods rich in magnesium (leafy greens, nuts, seeds), complex carbs for steady energy, and enough protein to stabilise blood sugar. Stay hydrated, and consider reducing stimulants like caffeine if you’re feeling jittery.
How to Reset the Stress Response
The nervous system is designed to be flexible: shifting between fight-or-flight and rest-and-digest as needed. The problem arises when it gets stuck in an acute response to stress. The good news: it can be trained back into balance.
Daily resets include:
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Breathing exercises: slow, deep breaths tell the brain you’re safe.
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Mindfulness: short meditation sessions lower cortisol.
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Nature exposure: even a 20-minute walk outdoors reduces stress hormones.
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Grounding rituals: consistent mealtimes, bedtimes, and movement anchor the nervous system.
These practices might seem simple, but they help retrain your body to feel safe again. And over time, that safety allows rest, repair, and growth.
Sleep: The Ultimate Reset
One of the most powerful ways to rebalance fight-or-flight is through quality sleep. During deep sleep, cortisol levels drop, tissues repair, and the nervous system recalibrates. Without this reset, the body wakes already primed for stress.
The trouble is, many people carry fight-or-flight into bedtime. Racing thoughts, tense muscles, and elevated cortisol make it hard to switch off. This is why “wired but tired” is such a common modern complaint.
Resetting the Stress Response at Night
If stress follows you into the night, extra support may help the body let go of survival mode. Fight-or-flight is vital for survival, but living in it daily undermines health, drains energy, and accelerates ageing. Modern triggers like screens, chronic worry, poor sleep, inactivity, and nutrient depletion can all trap you in this cycle, but none of them are permanent.
Simply Nootropics Genius Sleep can help: with Reishi Mushroom, magnesium bisglycinate, passionflower, and L-tryptophan, it’s designed to calm the nervous system, reduce cortisol-driven tension, and support natural sleep cycles.
By recognising the signs, addressing hidden triggers, and building daily resets into your routine, you can teach your body how to switch off stress and return to balance. And when it comes to resetting at night, Genius Sleep provides targeted support to help your system finally stand down.
