Fight or Flight vs Rest and Digest: How Your Nervous System Responds to Stress
Fight or Flight vs Rest and Digest: How Your Nervous System Responds to Stress
When we face a challenge or perceived threat, the body responds by adjusting heart rate, blood pressure, breathing, energy availability and hormone release.
These changes involve systems including the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis (O’Connor, Thayer and Vedhara, 2021). This stress response is normal and protective, helping us respond to what is happening around us.
The autonomic nervous system regulates many processes that happen automatically, including heart rate, blood pressure, breathing and digestion. It includes two major branches involved in stress and recovery: the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS). Rather than functioning as a simple on/off switch, these systems continually interact with the brain and hormonal systems to adjust according to the body's changing needs (Goldstein, 2021).
Sympathetic Nervous System: “Fight or Flight”
The sympathetic nervous system is commonly associated with the “fight or flight” response. When activated, it can contribute to an increased heart rate and blood pressure, greater alertness, changes in blood flow and increased availability of energy.
Importantly, this response isn't limited to physical danger. Everyday experiences such as deadlines, difficult conversations, public speaking and multitasking can also activate physiological stress responses (Becker et al., 2023).
While these responses are useful in the short term, constantly feeling “switched on” can make it important to consider how we are supporting recovery. At Realign Health Clinic, our approach considers the whole person, with services including chiropractic care, massage therapy and acupuncture that can form part of an individual's broader approach to movement, wellbeing and recovery.
Parasympathetic Nervous System: “Rest and Digest”
The parasympathetic nervous system supports processes associated with recovery, digestion and energy conservation. One of its major pathways involves the vagus nerve, which helps regulate organs including the heart.
However, “fight or flight” and “rest and digest” aren't completely separate states. The sympathetic and parasympathetic systems continually interact, allowing the body to adapt its response depending on what is required (Goldstein, 2021).
Supporting the body doesn't necessarily mean trying to stay in a constant state of relaxation. Instead, it means having opportunities to shift between activation and recovery as the demands of daily life change.
What Happens When Stress Keeps Repeating?
Short-term stress can be useful, helping increase alertness and energy when responding to a challenge. However, when stress is frequent or prolonged without adequate recovery, it may influence autonomic regulation, the HPA axis, cortisol signalling, immune processes, sleep and health behaviours (O’Connor, Thayer and Vedhara, 2021).
Stress can also influence how we experience physical symptoms. During stressful situations, breathing and muscle activity may change, while stress-response systems can interact with mechanisms involved in pain processing. Research suggests that changes in autonomic and HPA-axis function may contribute to how people with persistent pain respond to stress and process symptoms (Wyns et al., 2023).
This doesn't mean that stress is the cause of pain. Pain is multifactorial and can be influenced by tissue health, previous injury, physical load, sleep, activity levels, general health and psychosocial factors.
If you're experiencing ongoing muscle tension, stiffness or musculoskeletal discomfort, chiropractic care and massage therapy at Realign can be used alongside appropriate movement and lifestyle strategies to support your individual needs.
Can We Encourage the Body to Wind Down?
Recovery isn't about completely eliminating stress. Instead, it is about giving the body opportunities to adapt and recover.
Slow, controlled breathing may help support autonomic regulation. A systematic review and meta-analysis found that voluntary slow breathing increased measures of vagally mediated heart rate variability, including following repeated practice (Laborde et al., 2022).
Other ways to support recovery include getting adequate sleep, maintaining regular physical activity, taking breaks during prolonged periods of concentration and spending time away from work demands.
For some people, hands-on care can also be part of their overall wellbeing routine. Massage therapy may help address areas of muscular tension and support relaxation, while acupuncture may be considered as part of a broader approach to managing stress, tension and wellbeing. Chiropractic care can also support healthy movement and musculoskeletal function.
The right approach will depend on the individual, which is why an assessment can be useful when symptoms are persistent or affecting your everyday activities.
The Take-Home Message
“Fight or flight” and “rest and digest” are useful ways to understand some aspects of the autonomic nervous system, but our physiology is more complex than two opposing states.
The sympathetic nervous system isn't the enemy. It helps us respond to exercise, deadlines, danger and everyday challenges. The goal isn't to eliminate stress, but to create opportunities for the body to recover, adapt and respond appropriately to what comes next.
At Realign Health Clinic, we take a whole-person approach to movement, recovery and wellbeing. Whether you're dealing with muscle tension, ongoing aches, movement concerns or simply want to support your body through periods of increased stress, our team can help you explore which approach may be appropriate for you.
Looking for support with muscle tension, stress-related discomfort or your overall wellbeing? Our team at Realign Health Clinic offers chiropractic care, massage therapy and acupuncture to support your individual needs. Get in touch or book an appointment to find out which service may be right for you.
References
O’Connor, D. B., Thayer, J. F., & Vedhara, K. (2021). Stress and health: A review of psychobiological processes. Annual Review of Psychology, 72, 663–688. https://doi.org/10.1146/annurev-psych-062520-122331
Becker, L., et al. (2023). Differences in stress system (re-)activity between single and dual- or multitasking in healthy adults: A systematic review and meta-analysis. Health Psychology Review, 17(1), 78–103. https://doi.org/10.1080/17437199.2022.2071323
Goldstein, D. S. (2021). Stress and the “extended” autonomic system. Autonomic Neuroscience, 236, 102889. https://doi.org/10.1016/j.autneu.2021.102889
Laborde, S., et al. (2022). Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis. Neuroscience & Biobehavioral Reviews, 138, 104711. https://doi.org/10.1016/j.neubiorev.2022.104711
Wyns, A., et al. (2023). The biology of stress intolerance in patients with chronic pain—State of the art and future directions. Journal of Clinical Medicine, 12(6), 2245. https://doi.org/10.3390/jcm12062245
