Exercise & Stress PDF

Monday, February 12, 2024 EXERCISE & STRESS AEROBIC EXERCISE - Sustained activity involving the major muscle groups that does not require more oxygen than can be taken in - Sustained activity involving the major muscle groups - Strengthens cardiovascular system and increases overall strength and sta...

Monday, February 12, 2024 EXERCISE & STRESS AEROBIC EXERCISE - Sustained activity involving the major muscle groups that does not require more oxygen than can be taken in - Sustained activity involving the major muscle groups - Strengthens cardiovascular system and increases overall strength and stamina Examples include jogging, biking, rope jumping - Studies indicate exercise three times a week to acquire the bene ts of aerobic exercise ANAEROBIC EXERCISE - High intensity to trigger anaerobic metabolism Requires more oxygen than can be taken in - Short duration: seconds up to 2 minutes - Examples include sprinting, weight lifting PHYSICAL FITNESS COMPONENTS - Muscle strength and endurance Cardio respiratory endurance Flexibility Body composition Agility PHYSICAL BENEFITS OF EXERCISE Improves function and elasticity of lungs Delays the onset of degenerative aging Increases production of red blood cells in bone marrow Strengthens heart muscle and improves circulation Lower resting pulse rate Burns calories and improves food absorption Improves muscle tone and endurance Reduces LDL and serum cholesterol Increases HDL cholesterol Exercise and the Stress Response The relationship still unclear (bidirectional relationship) - If someone is stress, they are likely to exercise less - If someone is not t, they are likely to experience more stress fi fi 1 Monday, February 12, 2024 VARIOUS THEORIES Exercise may lead to changes in the HPA axis and the sympathetic nervous system - Findings show low cortisol and catecholamine levels in t individuals - How: 1. Resting levels in t individuals are lower (rHR~ 60bpm vs Non- t rHR~80bpm) When placed under stress, the bpm increase by 20 (80bpm vs 100bpm) Response to stress is the same, but t individuals start at lower levels 2. Difference in stress response is different (rHR~ 60bpm vs Non- t rHR~80bpm) When placed under stress, the bpm increase is different: Fit by 10 and non- t by 30 (70bpm vs 110bpm) Fit individuals response to stress is lower than non- t (= increasing their difference) 3. Recovery time is different (rHR~ 60bpm vs Non- t rHR~80bpm) When placed under stress: Fit by 10 and non- t by 30 (70bpm vs 110bpm), but t individuals get back to baseline faster - Not important how high you go, rather how fast you recover - Fit individuals have less to recover and do it faster Fitness leads to stress being less taxing on the heart: heart is not very elevated in its response for very long Exercise may increase endogenous opioid activity and result in a better mood - When exercising, it triggers natural opioid activity (makes you feel better/high) - Helps to interpret situations as less stressful Study — Aerobic Fitness and SNS Response Goal: aerobic tness and the stress response Measures: HR, BP, self-reports, and catecholamines Results: ✓ Fit individuals have sizable smaller stress response than un t individuals ✓ Aerobically t individuals exhibit: ✓ A diminished SNS response upon exposure to stress (Boutcher, 2004) ✓ Quicker recovery from stress exposure (Spalding et al, 2004) fi fi fi fi fi fi fi fi fi fi fi fi fi 2 Monday, February 12, 2024 Natural opioids help reduce anxiety and depression levels ** depends on the situation People still go through traumatic situations, exercise is not a cure, but it does help to boost mood (short-term) NK: natural killer STRESS, EXERCISE AND TELOMERE LENGTH Telomeres: repetitive DNA protein complexes that cap chromosomal ends and protect it from deterioration Study — Stress, Exercise and Telomere Length Participants: women who underwent blood draw for telomere length analysis, classi ed into 2 groups: Sedentary (irregular physical activity) and Active (regular exercise) Method: completed perceived stress scale and minutes of vigorous activity recorded for 3 days Results: ✓ Sedentary: the more perceived stress, the shorter the telomere ✓ Active: the effect perceived stress on telomere length is null ✓ i.e. exercise nulli es the effect of stress Study — Exercise and perceived stress Participants: thousands of working adults, 57% women Method: Level of physical activity measured with the National Health Interview Survey/ Level of stress measured with Lefebvre & Sanford’s Strain Questionnaire ✓ Individuals with high PA were 49% less likely to report high perceived stress and 75% less likely to report moderate perceived stress as compared to individuals low in PA ✓ Interesting to note ✓ Aerobic exercise was more popular amongst participants than anaerobic exercise ✓ 62% of participants who were found to have a high level of exercise listed walking as their primary exercise = any exercise is bene cial; not need to spend 3h in the gym fi fi fi 3 Monday, February 12, 2024 E ect of Exercise on Stress-Related Disorders POST TRAUMATIC STRESS DISORDER Study — Diaz (2007) Population: 14-17 year old females diagnosed with PTSD in a residential facility (no control group) Method: PTSD symptoms measured by a battery of tests before and after a 5 week, 15 session aerobic exercise program Results: ✓ 91% of participants exhibited a signi cant reduction of symptoms OBSESSIVE COMPULSIVE DISORDER Study — Abrantes et al. (2009) Population: patients in OCD clinic, 18-65 years old given a moderate intensity 12 week aerobic exercise regime tailored to their age and tness level Method: NIMH self-report scale was administered before and after exercise Results: ✓ Symptoms decreased considerably ✓ Large to medium effect sizes in reduction of negative mood and anxiety ✓ Large to small effect sizes in reduction of obsessions and compulsions ✓ In both cases, larger effects were seen earlier in the course of treatment (starting the exercise program reduces OCD symptoms) GENERALIZED ANXIETY DISORDER Study — Merom et al. (2007) Population: Clinic outpatients Method: Randomly assigned into cognitive-behaviour therapy (CBT) versus CBT + a walking program Results: ✓ Participants in the “walking” group showed only a small improvement in depression scores ✓ patients who made greater improvements in their tness experienced greater symptom relief Summary Exercise has a direct impact on physiological stress response mechanisms Exercise moderates the effects of stress on telomere length Exercise leads to a reduction in perceived levels of stress Exercise can improve symptoms of psychological disorders linked with stress Exercise improves longevity Aerobic exercise is low-impact and suitable for a variety of ages and tness levels fi fi fi fi ff 4