Lance Corporal Jones from Dad’s Army had one reaction to stress: “Don’t panic!” And it turns out, that might be the key to ageing well. Regulating our nervous system and emotional balance is central to long-term health. In this article, I explore the two gears of our nervous system, how they affect longevity, HRV as a measure of resilience, and what you can do to achieve a better emotional balance.
The Two Gears: Sympathetic and Parasympathetic
Your autonomic nervous system has two modes:
- Sympathetic (“fight or flight”): drives energy, alertness, and motivation
- Parasympathetic (“rest and digest”): supports calm, digestion, sleep, and recovery
We need both. The sympathetic system kicks in during stress or exertion, speeding up heart rate and suppressing digestion and is needed for motivation, responding to challenges and harnessing energy. We need short bursts of the sympathetic system. The parasympathetic system follows, slowing things down, restoring balance, and aiding recovery, ideal for long-term health.
During waking hours, you may be 40–60% sympathetic-dominant—especially for work and regular movement. But during meals and sleep, the parasympathetic system should take over, aiming for a daily rhythm of about 25% sympathetic and 75% parasympathetic activity.
The real danger is when the sympathetic system gets stuck “on,” leading to chronic stress, inflammation, poor sleep, and faster ageing.
The Vagus Nerve: Your Calm Control Centre
The vagus nerve is the main highway of the parasympathetic system. It runs from your brainstem through your heart, lungs, and gut—and sends 80% of its signals from the body to the brain, not the other way round.
That means your emotions are deeply shaped by your physical state: your breathing, heartbeat, and digestion all feed into how you feel.
A strong, well-toned vagus nerve (known as good vagal tone) slows your heart, lowers stress hormones, supports digestion, and improves emotional regulation. A high vagal tone is a measure of your “rest-and-repair” fitness level and is linked to high heart rate variability (HRV) and longer life —and it’s something you can train.
Heart Rate Variability (HRV): A Window into Resilience
HRV measures the variability between heartbeats—not your heart rate, but how much that interval between beats fluctuate. It reflects in real time how flexible your nervous system is in shifting between stress and recovery.
- High HRV = strong recovery ability, good parasympathetic activity
- Low HRV = chronic stress, poor sleep, inflammation, etc and dominant sympathetic activity
HRV varies across the day and is influenced by sleep, stress, food, activity, and mood. It’s best measured first thing in the morning, when it will be high if you’ve had a good night’s sleep, before food and activity. After that it drops as the sympathetic nervous system becomes more active during the day.
Of note, a chest strap typically provides a more accurate HRV measure than a wrist or ring wearable that uses optical sensors. Also, each device has its own HRV measure, such as average score during sleep, or spot lowest score during the last deep sleep, or average score during the day. This makes comparisons between users more difficult, but for a user the results should be consistent.
Multiple studies, including a 2017 meta-analysis in Psychosomatic Medicine, show that low HRV is significantly associated with higher all-cause mortality. The following paper showed that the lowest quartile for HRV had a 56% increased risk of death versus the other three quartiles combined. See Heart rate variability in the prediction of mortality: A systematic review and meta-analysis of healthy and patient populations, Marc Jarczok, et al 2013
HRV peaks in young adulthood when the nervous system is most flexible and responsive, then gradually declines with age as our blood vessels stiffen and we recover slower from stress and exertion.
HRV increases as you get fitter, because your nervous system becomes more resilient and adaptable, especially the balance between your sympathetic and parasympathetic systems. A fit person has a fast stress-recovery cycle. Also, with increasing fitness your resting heart rate usually falls and with this there is a greater beat-to-beat variation (the measure of HRV).
Genetics vs. Lifestyle
About 40% of the nervous system balance is genetic. People with Type A behaviour—competitive, impatient, overcommitted—tend to be in sympathetic overdrive. This is linked to lower HRV, higher cortisol, and greater risk of hypertension and cardiovascular disease.
But even those who aren’t naturally Type A can be pulled into chronic stress by modern life: deadlines, screens, news, caffeine, and poor sleep all activate the sympathetic system.
The result? A sympathetic nervous system stuck in overdrive—a silent driver of disease, ageing, and burnout.
Training the Nervous System
Don’t panic—the nervous system is trainable at any age. Even within 2–3 months, you can make measurable gains in HRV and emotional resilience so you bounce back faster, recover better and stay calmer under pressure.
Here are some simple and effective tools:
1. Breathwork or Meditation
Breathing slowly—5 to 6 breaths per minute—is the sweet spot to activate the vagus nerve and increases HRV. Meditation also shifts the nervous system into balance, reducing sympathetic dominance. With over 100 styles of meditation, there’s one for everyone.
2. Vagus Nerve Stimulation
Humming, chanting, singing directly stimulates the vagus nerve and sends a signal tp the brain “we’re safe, calm down”. This together with breathwork and meditation, lowers your heart rate even more.
Splashing cold water on your face (around eyes, nose, and forehead) triggers a primitive reflex slowing heart rate and increasing parasympathetic tone.
3. Gentle Nature Walks
A 20-minute walk in green space boosts dopamine and serotonin, lowers cortisol, and improves HRV. A Japanese study found significantly higher HRV after just 30 minutes of a forest walk, referred to as “forest bathing.”
Even hugging a tree (yes, really) can feel grounding and good. I know because I’ve tried it!
4. Yoga or Tai Chi
Both integrate breath and mindful movement—ideal for calming the body and training the parasympathetic system.
5. Regular Aerobic Exercise
Exercise builds cardiovascular fitness and raises HRV—but avoid overtraining, which suppresses vagal activity and keeps the body in “fight or flight” mode.
6. Reduce Alcohol, Sugar, and Stress
Alcohol disrupts HRV and sleep. Equally, sugar spikes blood glucose and triggers a stress response. Chronic stress locks you in sympathetic mode—learning to downshift is vital.
7. Sleep Like It Matters
Deep sleep is your nervous system’s recovery window. Stick to a regular routine, wind down without screens, and let your parasympathetic system do its job.
3 Takeaways to Reset Your Nervous System and increase your HRV
Your nervous system is not fixed—you can improve it at any age, even if you’re a Type A personality. You don’t need to be a monk, but you just need to recover like one.
Don’t Panic—Do This Instead:
- Breathe slow (5–6 breaths per minute) to trigger calm
- Walk outside and reconnect with natural rhythms
- Sleep like it matters—because it really does
Master these, and you’ll not just survive the stress of modern life—you’ll thrive with a higher HRV and enhanced longevity. Your partner may also value the change in your mindset!
The more effectively you can switch gears from “fight or flight” to “rest and repair,” the longer—and better—you’re likely to live.
