Hacking the stress system: the stress response as an adaptive trait that can work for or against you X - Optimising the stress response for greater performance The three major ways to manipulate the stress response ´Stress reduction ´ ´Habituation ´ ´Modulation The most effective mechanisms to reduce or control the acute stress response all involve feedback loops ´It is hard to control ´Thoughts ´Emotions ´Physiological states ´ ´Behaviour is much easier and that will alter all the above ´ ´Stress often requires an expression to movement (be that physiological or psychological – behaviour is the key!) Forward movement: The nucleus reuniens ´A small nucleus in the thalamus ´ ´Secretes dopamine in response to forward movement ´ ´Behaviour effects ´In rats it increases willingness to fight harder ´In people… (we are not sure yet. Running or going for a walk seem to calm people down, but I am not aware of any studies which confirm this mechanism. We are awaiting data from a current project though. So, I hope I can confirm this hypothesis soon) Zimmerman, E. C., & Grace, A. A. (2016). The nucleus reuniens of the midline thalamus gates prefrontal-hippocampal modulation of ventral tegmental area dopamine neuron activity. Journal of Neuroscience, 36(34), 8977–8984. https://doi.org/10.1523/JNEUROSCI.1402-16.2016 Acute stress reduction ´Breath work ´ ´Eyes ´ ´Left-brain / right-brain cross talk ´ ´Relaxation practices ´Meditation ´Yoga ´Sports Breath work ´Double sigh ´Off load much more carbon dioxide ´ ´Respiratory sinus arrhythmia ´Inhales: diaphragm moves down, more space for the heart, brain sends a signal to speed up to keep blood pressure steady. ´Basis for Heart Rave Variability (HRV) Feldman JL. Neurobiology of breathing control. Where to look and what to look for.. Advances in experimental medicine and biology, 1995. Visual control: Can you use the eyes to control stress? ´Eyes – 2 functions ´ ´Detecting shapes, colours, etc. (vision) ´ ´Communicate to the brain – active or inactive (Cues about time of day, stressors, etc.) (YES! Another feedback loop!!) ´Relaxed (panoramic vision) ´Stressed (focussed vision) ´ ´ Left-brain / right brain cross talk ´Over activity in the left side of the brain may lead to overthinking ´ ´Activity with the left hand, which cross talks to the right hemisphere, leads to an overall downregulation of brain activity Mesagno, C., Beckmann, J., Wergin, V. V., & Gröpel, P. (2019). Primed to perform: Comparing different pre-performance routine interventions to improve accuracy in closed, self-paced motor tasks. Psychology of Sport and Exercise, 43(January), 73–81. https://doi.org/10.1016/j.psychsport.2019.01.001 Mesagno, C., & Beckmann, J. (2017). Choking under pressure: theoretical models and interventions. Current Opinion in Psychology, 16(June), 170–175. https://doi.org/10.1016/j.copsyc.2017.05.015 Meditation (a great feedback loop?) ´Breath work ´Deliberate focus on slowing down mental function ´Focus of the mind ´Calm ´Present ´Positive aspects of one’s life ´ Habituation Cold exposure: Acute response to cold ´Stress response ´ ´Vasoconstriction ´Hyperventilation ´Shivering ´Sympathetic activation ´Immune system ´Noradrenaline Šrámek, P., Šimečková, M., Janský, L., Šavlívková, J., & Vybíral, S. (2000). Human physiological responses to immersion into water of different temperatures. European Journal of Applied Physiology, á+, 436–442. Søberg, S., Lo, J., Philipsen, F. E., Pedersen, B. K., Karstoft, K., Philipsen, F. E., … Ahrens, E. (2021). Article Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young , healthy , winter-swimming men ll Altered brown fat thermoregulation and enhanced cold-induced thermogenesis in young , healthy , winter-swimming men. https://doi.org/10.1016/j.xcrm.2021.100408 Cold Exposure: Secondary response to cold ´Vasodilation ´Thermogenesis (shivering) ´Parasympathetic activation ´Anti-inflammatory Cytokines ´Mood enhancement (probably in response to dopamine outflow) Cold exposure: Repeated cold exposure ´Brown fat activation and production ´Non-shivering thermogenesis ´Improved insulin sensitivity ´Weight loss ´Immune activation Physical exercise (stress) – see lecture IX We evolved for hunger ´For most of evolutionary history we went through regular short periods of food deprivation. ´Storing excess energy ´Insulin ´ ´Cleaning out the system ´ What happens when you stop eating? ´The first 24 hours ´You burn through your glycogen stores ´ ´ ´After 2/3 days you switch from burning glucose to fat and protein ´The more fat adapted you are the easier this transition will be ´Enhanced mood and cognitive function (due to ketone metabolism) Autophagy: the medicinal qualities of consuming nothing ´During hunger, the body gets a chance to burn off a lot of cells, which do not function optimally. ´ ´ ´During refeeding these cells are reconstituted if necessary Taylor, P., Alirezaei, M., Kemball, C. C., Flynn, C. T., Wood, M. R., Lindsay, J., … Whitton, J. L. (2014). Short-term fasting induces profound neuronal autophagy. (November), 37–41. https://doi.org/10.4161/auto.6.6.12376 Pietrocola, F., Pol, J., & Prof, G. K. (2016). Fasting improves anticancer immunosurveillance via autophagy induction in malignant cells. Cell Cycle, 15(24), 3327–3328. https://doi.org/10.1080/15384101.2016.1224797 Modulation Much less is known about the manipulation of the acute stress response for optimal performance ´Internal reward generation ´Small milestones (micro-slicing activities) ´ ´The effects of altruism ´We handle so much more if we can find the strength to care for others while we struggle ´(Oxytocin?)