L6 - PA Benefits & Risks

• Short term benefits of PA:

  • Feeling better/more energetic
  • Having fun
  • Social time
  • Lower stress
  • Relaxation
  • Meeting new people
  • Improve fitness/function
• Long term benefits of PA:

  • Better overall health
  • Improved posture/balance
  • Increased confidence
  • Improved weight control
  • Stronger muscles & bones
  • Maintain independence, esp in older people
  • Decrease disease risk
• Health benefits of PA:

  • Improvement in cardiovascular function
  • Improvement in respiratory function
  • Enhancement of muscular fitness
  • Reduction in cardiovascular disease risk factors
  • Decreased morbidity & mortality
• Anatomy - The Heart

  • Cardiovascular system made up of heart & blood vessels
  • Blood transportation network
  • Nutrients, oxygen & waste in blood
• Cholesterol

  • Is a lipid molecule
  • Helps maintain structure of cell membranes
  • Precursor to:
  • Steroid hormones
  • Bile acids
  • Vitamin D
  • Ingest new cholesterol
  • Most of our cholesterol is obtained through recycling
• Cholestrol Types:

  1. HDL (High Density Lipoprotein)
  2. Remove cholesterol from, cells
  3. Help reverse atherosclerosis
  4. LDL (Low Density Lipoproteins)
• High Cholesterol:

  • Atherosclerotic plaques cause:
  • Myocardial infarctions
  • Strokes
  • Peripheral vascular disease
• Improvement in CV function:

  • Decreased resting HR
  • Increase in HDL & decrease in LDL
  • Decreased blood pressure
  • Increased blood flow
  • Oxygen delivery to tissue
  • Redistribution of blood flow during exercise
  • Increasing venous return → muscle pump
  • Increased capillary density
  • Increased exercise threshold for blood lactate accumulation
• Respiratory system

  • Main job: gas exchange
  • Inhale:
  • Diaphragm pulls down + chest muscles contract to pull open → inhale air like a vacuum
  • Exhale:
  • Muscles relax, lungs go back to normal size → pushing the air out
• Improvement in respiratory function

  • Increased number of alveoli & capillaries around the alveoli
  • Increased strength of intercostal muscles & diaphragm
  • Increase lung volume due to increased tidal volume & vital capacity
• Diabetes Mellitus:

  • Body has trouble moving glucose from blood into cells → blood sugar levels constantly high
  • Type 1 Diabetes:
  • Autoimmune destruction of the pancreas
  • Type 2 Diabetes:
  • Body makes insulin but cells are insulin resistant
• Adaptations to exercise:

  • Decrease basal & glucose stimulated insulin levels
  • Increase GLUT4 → increase glucose uptake capacity
  • Increase enzyme number & activity - improves glucose & fat metabolism
• Skeletal system:

  • Skeletal comprised of 206 bones
  • 5 types of bones:
  • Long bones
  • Short bones
  • Flat bones
  • Sesamoid bones
  • Irregular bones
  • Bones remodelled throughout life
• Skeletal muscle:

  • Maintain posture & stabilise joints
  • Generate lots of heat as byproduct
  • Fascia = 3 part connective tissue framework
  • Epimysium - outermost layer
  • Perimysium - subdivides muscle fibres into fascicles
  • Endomysium - surrounds the muscle fibre
  • Muscle fibres contain bundles of myofilaments
• Improvements in musculoskeletal:

  • Increased level in muscle mass (hypertrophy)
  • Increased strength of tendons
  • Increased strength of ligaments
  • Increased bone mass
  • Decrease pain & disability in osteoarthritis
  • Decrease chronic back pain
• Reduction in CVD Risk Factors from Exercise:

  • Dyslipidemia
  • Increase HDL cholesterol
  • Decrease triglycerides
• CVD Risk Factors:

  • Dyslipidemia
  • Hypertension
  • Obesity
  • Diabetes
• Reduction in CVD Risk Factors from Exercise:

  • Hypertension
  • Decrease blood pressure at rest
• Reduction in CVD Risk Factors from Exercise:

  • Obesity
  • Decrease total body fat
  • Decrease visceral body fat
• Reduction in CVD Risk Factors from Exercise:

  • Diabetes
  • Decrease insulin needs
  • Increase glucose tolerance
  • Decrease inflammation
• Decreased Morbidity & Mortality:

  • Primary prevention
  • (ie interventions to prevent the initial occurrence)
  • Higher activity &/or fitness levels are associated with:
  • Decreased incidence & mortality for:
  • Coronary artery disease
  • Cardiovascular disease (CVD)
  • Hypertension
  • Type 2 diabetes mellitus
  • Metabolic syndrome
  • Bone fractures
  • Colon & breast cancer
• Decreased Morbidity & Mortality:

  • Secondary prevention
  • (ie interventions after an event or diagnosis)
  • All cause mortality & CV mortality in patients after a heart attack who participate in cardiac rehabilitation exercise training, esp as a component of a multifactorial risk factor reduction
  • Decrease the risk of serious side effects following the individual’s diagnosis, for example
  • Limb amputation after diabetes diagnosis
  • Stroke after hypertension diagnosis
• Other Benefits of PA:

  • Reduced anxiety & depression
  • Improved cognitive function
  • Enhanced feelings of well being
  • Enhanced performance of work, recreational & sport activities
• In older adults benefits of PA:

  • Increased physical function & independent living
  • Decreased risk of falls & injuries from falls
  • Prevention or mitigation of functional limitations
  • Effective therapy for many chronic diseases
• Inactivity physiology:

  • Effect of being sedentary
  • Decrease Insulin sensitivity
  • Decrease Glucose tolerance
  • Decrease Bone mineral density
  • Decrease Muscle mass
  • Decrease HDL
  • Increase Fasting Insulin
  • Increase Fasting glucose
  • Increase LDL
  • Increase triglycerides
  • Overall - increased risk of disease
• Safety Considerations for PA:

  • No PA is completely risk free. However, health benefits of PA generally outweigh the risks
  • Inactive individuals & individuals with existing health conditions should start off slow & gradually build up to the minimum recommended PA level
• Prevention of Exercise Related Cardiac Events:

  • Health care professionals’ knowledge of pathologic conditions associated with exercise related events to provide adequate evaluation
  • Recognise symptoms (eg excessive, unusual fatigue & chest pain) & seek prompt medical care if such symptoms develop
• Prevention of Exercise-Related Cardiac Events:

  • Health care facilities staff should be trained in managing cardiac emergencies
  • PA individuals should modify their exercise programme in response to variations in their exercise capacity, habitual PA level & the environment
• Recommended Activity Changes for NZ Adults :

  • Driving short distances → Walking, cycling or scootering
  • Prolonged driving → Regular breaks during driving
  • Taking a lift or escalator → Using the stairs
  • Prolonged sitting/screen time → Light activity such as standing & walking
  • Light activity → Moderate activity
  • Moderate activity → Longer or more frequently moderate activity; higher intensity activity