Mental Health and Exercise pt. 2 PDF

Mental Health and Exercise pt. 2 Dr. Ross Murray KINESIOL 3H03 Nov 12, 2024 Week #11 mcmaster.ca  Announcements and Updates I. FINAL Lecture Tues Nov 19! II. Test #2 – Tues Nov 26th 10:30am – 11:30am I. Testable con...

Mental Health and Exercise pt. 2 Dr. Ross Murray KINESIOL 3H03 Nov 12, 2024 Week #11 mcmaster.ca  Announcements and Updates I. FINAL Lecture Tues Nov 19! II. Test #2 – Tues Nov 26th 10:30am – 11:30am I. Testable content = material from 2nd half of the course II. Same format as Test #1 III. Final Assignment will be posted on Wed Nov 27th I. Due FRI Dec 6th @ 11:59 pm  Check-In Recap from previous lectures PA associated with depression and anxiety symptoms Higher sedentary behavior leads to increased depression and anxiety symptoms Very brief - 7 days! A single bout of aerobic exercise lowers depression and anxiety symptoms Buffers against stress and improves mood Benefits people without mental health problems AND people with mental illness More research needed regarding impact of acute exercise intensity, duration, and type Resistance exercise, HIIT, exercise snacks, etc. Outline and Learning Objectives Investigate research on the impact of exercise training on anxiety and depression Understand the ‘optimal dosage’ recommendations for exercise training and depression Compare and contrast the proposed mechanisms by which exercise improves depression  Exercise Training for Anxiety Vs. Aerobic Training Resistance Training Aerobic Training and Anxiety Aerobic training = most researched type of exercise Has small but significant effects on lowering anxiety What is the optimal ‘dose’ of exercise? Intervention Length: Occurs within 3-6 weeks of training! Frequency: 3-4x per week = largest decrease in anxiety Duration: 20-30 min = largest decrease in anxiety Participant Health Status Matters: Anxiety decrease greater in people without anxiety disorders… Still, exercise training lowers anxiety in people w/ anxiety disorders Rebar et al., (2015) Health Psych Rev  Exercise Training for Anxiety Vs. Aerobic Training Resistance Training Effectiveness comparable other anxiety treatments ?  Resistance Training and Anxiety Meta-analysis of Resistance Training and Anxiety RT significantly reduces anxiety symptoms Type of RT not important Greater effects observed in healthy population Still beneficial for people with anxiety disorders Gordon et al. 2017 Worsened Anxiety Scores Improved Anxiety Scores  NO DIFFERENCE IN ANXIETY BETWEEN AT & RT Vs. Aerobic Training Resistance Training Comparable other anxiety treatments Significantly reduces anxiety symptoms Exercise Training and Depression  Exercise Training and Depression Prevention Meta-Analysis Population Studied Analysis of 8 meta-analyses 134 individual studies total! Effect of exercise training on depression Wide age range Exercise prescription varied Type, intensity, duration, etc. Take Home Points Exercise training depression symptoms across the lifespan… Effect prevention tool ES = effect size Improved Depression Scores Worsened Depression Scores 95% CI = confidence interval Hu et al 2020 Exercise is as effective as (and sometimes more effective) than traditional therapies  vs. Exercise, Medication, or Both in Patients with MDD 156 adults with diagnosis of MDD (mild to moderate-to-severe depression) 16-week intervention (4 months) Exercise Training: 3x/week aerobic training @ 70-85% HRmax Medication: antidepressant medication Combined: exercise + medication Exercise lowers depression to the same extent as medication Exercise increases physical fitness (VO2max) Blumenthal et al. (1999) JAMA  Changes in Depressive Symptoms During Intervention Rapid drop in depression in all treatment groups Babyak et al., (2000) Psycho Med Blumenthal et al. (1999) JAMA 6 Month Follow-Up After Treatment Why did the combination group experience similar relapse rates as the medication group? Babyak et al., (2000) Psycho Med  Why did the combination group experience similar relapse rates as the medication group? + =  Exercise “Dosages” for Treating MDD What is the optimal prescription? Mode:  Doesn’t matter; aerobic or resistance exercise Mixing AT + RT may be better than AT or RT alone Intervention length:  At least 10 weeks* (although changes are seen earlier) Frequency:  3 to 5x per week *for long-lasting anti-depressant effects Exercise “Dosages” for Treating MDD What is the optimal prescription? Intensity:  Aerobic: 50–85% of maximal heart rate;  Resistance: Higher intensity (e.g., 80% of 1RM) is more effective than lower (e.g., 20% 1RM) Duration:  30 to 60 mins per session (largest decrease seen for 45-60mins) Is anything missing from this prescription? Everyone is different, there will be variations Summary on Exercise Training and Depression 1) PA has protective benefits against symptoms of depression 2) Protective effects increase with greater levels of physical activity I. Dose-response relationship 3) Exercise may be an adjunct to the professional treatment of severe depression 4) Optimal types and/or amounts of activity still unclear Mechanisms of Change  Mastery Hypothesis  Psychological benefits from feelings of accomplishment or mastery post-exercise  Mastery gives a sense of greater self-worth and personal control over the environment Craft (2005) Psych Sport Exer Evolutionary Basis of Brain Health Neurochemical + Neurogenesis Hypothesis Brain’s original evolutionary function = to facilitate movement Brain evolved mechanisms that stimulate adaptation in response to physical and cognitive demands Adaptation increases resilience and resistance to stress Like skeletal muscle! Sedentary lifestyle = reduces positive adaptations & capacity to buffer stress  Neurochemical + Neurogenesis Hypothesis Exercise feel-good hormones: opioids, endorphins, endocannabinoids May also restore balance of neurotransmitters that are altered with depression (serotonin & dopamine) Exercise brain-derived neurotrophic factor (BDNF) BDNF is a growth factor that stimulates neurogenesis (growth of new neurons) Occurs specifically in the hippocampus Yellow = hippocampus Neurogenesis is like hypertrophy for the brain Big gains for big brains Neurogenesis buffers against stress and protects against negative mental health symptoms  Support for Neurogenesis + Neurochemical Hypothesis Exercise Training and the Hippocampus Study Details: Adults with MDD Supervised aerobic training 3x/week for 3 months MRI used to measure hippocampal size (volume) Findings: hippocampal volume with exercise training is positively associated with improved depression scores Limitations: Adherence was poor! People exercise on average 1 day per week… Krogh et al., 2014  BDNF and Depression Blood concentrations of BDNF significantly in MDD Change in BDNF Anti-depressant treatment significantly increases BDNF BDNF associated with depression scores following treatment BDNF is a biomarker for depression improvement after anti-depressant treatment Improved Depression Scores Brunoni et al (2008) Int J Neuropsychopharm  End of Lecture Reflection Neurochemical + Neurogenesis Hypothesis: How could you apply this knowledge when designing an intervention to improve mental health?  Summary and Take Home Points Numerous proposed mechanisms underlying exercise improving depression Likely a combination of multiple factors Neurochemicals released during exercise induce numerous positive changes Affect and mood Restore neurotransmitter balance Stimulate neurogenesis via BDNF Increase resistance to stress Exercise is medicine, but only if you take it… The best prescription is the exercise that people will continue to do