Week 12 - Physical Activity and the CV-R System

• What is the definition of physical activity?

  Skeletal muscle movement that results in energy expenditure above resting levels.
• What is sedentary behavior?

  Activities while sitting or lying that have little or no movement.
• What does VO2max represent?

  The maximal rate that the body can take, transport, and utilize oxygen.
• What does MET stand for?

  Metabolic Equivalent, a method of expressing energy expenditure.
• What are the exercise intensity domains mentioned?

  Moderate, Heavy, Severe, Extreme.
• What factors control heart rate and ventilation during exercise?

  Carotid/central chemoreceptors, emotional factors, voluntary control, proprioceptors, and central radiation.
• When should heart rate or ventilatory responses to exercise be measured?

  At least 2-3 minutes into exercise.
• What happens to heart rate and ventilation during steady moderate exercise?

  Both increase gradually, reaching a steady-state at 2-3 minutes.
• What is the formula for minute ventilation?

  Tidal Volume x Breathing Frequency.
• What occurs to oxygen consumption during the first 3 minutes of exercise?

  It increases and levels out at about 3 minutes.
• Why does the body rely on anaerobic sources in the first 3 minutes of exercise?

  Due to the lag in cardiac and ventilatory responses.
• What happens to arterial oxygen and carbon dioxide levels during the initial phase of exercise?

  PaO2 is lower than optimal, and PaCO2 is higher.
• How does stroke volume change during exercise?

  It increases up to 40% to 60% of VO2max and then levels off.
• What determines stroke volume?

  Preload and afterload.
• What is the formula for cardiac output?

  Cardiac output = SV x HR.
• How does blood pressure respond to exercise?

  Systolic blood pressure increases, while diastolic pressure remains relatively unchanged.
• What does cardiopulmonary exercise (CPX) testing involve?

  Monitoring of respiratory gas exchange, minute ventilation, blood pressure, heart rate, and ECG.
• What does CPX testing help determine in patients with lung disease?

  Impairment in aerobic capacity and abnormalities in ventilation with exercise.
• How does cardiac output respond to exercise?

  It is a function of the rises in stroke volume and heart rate.
• What is the effect of regular physical activity on all-cause mortality?

  It delays all-cause mortality.
• How much physical activity should adults aim for weekly for substantial health benefits?

  At least 150 to 300 minutes of moderate-intensity or 75 to 150 minutes of vigorous-intensity aerobic activity.
• What additional activities should adults include for health benefits?

  Muscle-strengthening activities involving all major muscle groups on 2 or more days a week.
• What is the relationship between physical activity levels and myocardial infarction (MI) risk?

  Increasing physical activity levels results in reduced risk of MI.
• How does physical activity reduce hypertension risk?

  By reducing total peripheral resistance due to increased blood vessel diameter.
• What are some mechanisms by which physical activity reduces cardiovascular risk?

  Reduces BP, decreases LDL, increases HDL, decreases inflammation, and reduces blood clotting.
• What is the role of pre-participation screening in exercise?

  To assess risk stratification before engaging in physical activity.
• What is the source of the physical activity guidelines mentioned?

  US Department of Health and Human Services 2008.
• What is the significance of the PAGAC (2008) report?

  It provides guidelines for physical activity and cardiovascular health.