Lecture 7 - stress Flashcards
reaction-focused models
based on reaction of the human body to unspecific situations
- Cannon (1914)
- Selye (1956)
Cannon 1914
the body is in a state of homeostasis
- stimulus –> short-term effect (fight or flight)
Selye, 1956
general adaptation syndrome (long-term consequences)
o Alarm phase: immediate response to stressor –> sympathetic nervous system
o Resistance phase: effort to manage the stressor –> glucocorticoids
o Exhausting phase: exhaustion of physiological resources –> impairment of health
stimulus-focused models
stress is provoked by external stimuli
cognitive-transactional models
stress is a cognitive transaction between internal and external demands. It explains individual differenced and is based on a evaluative (appraisal) process.
CTM primary appraisal
nterpretation of stressor (what is at stake?)
CTM secondary appraisal
analysis of resources ( do I have the capacities to successfully deal with the stressor
CTM coping
overcoming stress
o Problem-focused: change the situation
o Emotion-focused: change your relationship to the situation
CTM re-appraisal
pacing and learning (are my attempts to reduce stress successful?)
physiological stress response
- sympathetic activation
- HPA activation
sympathetic activation
Cerebral cortex: classification of event as harmful
- Hypothalamus: early response of sympathetic nervous system arousal (fight or flight) –> stimulates medulla of adrenal glands –> secretes catecholamines, epinephrine, norepinephrine (cranked-up feelings)
- Leads to: increased heartrate, increased sweating, contraction of peripheral blood vessels, enhanced blood flow to muscles
HPA activation
Hypothalamus releases CRF –> stimulates pituitary gland –> ACTH –> stimulates adrenal cortex to release glucocorticoids –> cortisol
Conserves stores of carbohydrates
Reduces inflammation
Heps the body to return to steady state
Chronic high cortisol –> chronic stress –> higher risk for civilization diseases (CHD, mental disorders)
- Elevates growth hormone (prolactin) levels and beta-endorphin and enkephalin (responsible for immune-related disorders
stress and negative health outcomes
Russ et al (2012): analysis of relationship between stress and mortality
- Mortality risk twice as high for people with high stress scores
- Stress elicits strong physiological responses –> negative consequences for health
relationships between pa and stress
- physical activity reduces stress
- stress reduces physical activity
- physical activity <–> stress
3 types of studies
- Cross-sectional studies: high levels of pa are associated with lower perceived stress
- Prospective studies: baseline measures of physical activity can predict stress at follow-up
- Longitudinal studies: reciprocal (<–>) relationship between pa and stress
Aldana 1996
-Relation between leisure time pa and perceived stress
-N= 32.229 (big sample)
-Low amount of pa –> 0.78-0.62 times less likely to have less stress (1.0 at no pa)
-Moderate pa –>0.5 –> half the rate of perceived stress
-Causality: what influences what? Stress < – >pa
- Other studies: stress leads to reduction in pa
crossed-lagged panel design
a study of the relationships between two or more variables across time in which one variable measured at an earlier point in time is examined with regard to a second variable measured at a later point in time, and vice versa. (to look at causality)
Luz 2007
Perceived stress predicted pa negatively, not the other way around
stress buffer hypothesis
pa buffers the negative effects of stress on health
-Stress has bad negative consequences on health, pa reduces these negative effect
-Pa reduces reactivity towards stressors (HR, BP, cortisol)
-Pa gives more rapid recovery of stress parameters (cardiovascular and endocrine)
- cross-stressor response
cross stressor response
Pa functions as a stressor and trains the neurophysiological stress activity system, the stress systems adapts and therefor responds less strong to that and other stressors
Sothmann 1996
- cross-stressor response
- Conclusion: trained men reacted less strong (physiological and self-reports) to psychological stress compared to untrained men
O’Dougherty 2012
negative effects of critical life events on depressive symptoms are buffered by aerobic training
TSST
- trier social stress test
- naturalistic exposure to a socio-evaluative stressful situation
- 5 min public speaking task
- 5 min calculations in front of others
- 3 min preparation
EMA
ecological momentary assessment
- Method of assessing intense and chronic stressors in everyday settings
- Assessment of self-report questionnaires (stress and well-being) and physiological parameters (ECG, accelerometer) at fixed timepoints or at certain events using a smartphone
AA
ambulatory assessment
- Monitors movement, physiological functions, contextual information (GPS) and EMA in realtime
causes of stress during pa
- Physiological factors (intense training)
- Environmental factors (training conditions)
- Social factors (social relationships)
- Psychological factors (expectations)
Fletcher and Fletcher 2005
most important stressors in sport
- Stressors during or right before competition (fear, nervousness, competition density, previous failure)
- Organizational stressors (communication, media, travel)
- Chronic stress (constant high-performance pressure, financial uncertainty)
- Social stress (problems at home)
- Transition phases (junior –> senior, end of career)
