Cardiorespiratory Fitness & Exercise Programming

Cardiorespiratory Fitness Assessments and Exercise Programming

• Cardiorespiratory fitness (CRF) is the ability of the circulatory and respiratory systems to deliver oxygen to muscles during physical activity (VO2max).
• VO2 is a composite of three processes: oxygen consumption in the lungs, transporting oxygenated blood to active muscles, and extracting oxygen from blood to produce ATP.
• High CRF is associated with improved health and a reduced risk of cardiovascular disease (CVD).
• There is a dose-response relationship between exercise and reductions in chronic diseases. Improving one of the three systems (consumption, transport, or utilization) will improve VO2.
• The ACSM-EP's (American College of Sports Medicine – Exercise Physiologists) primary role is to help people develop and maintain their CRF.

Anatomy & Physiology

• The heart has four chambers: two atria and two ventricles. The left ventricle is responsible for pumping blood to the body.
• Vasculature includes veins and venules that carry deoxygenated blood and arteries and arterioles that carry oxygenated blood. Capillaries facilitate gas and nutrient exchange between blood and tissues.

Energy Systems

• The graph shows the relative contribution of different energy systems (ATP-CP, rapid glycolysis, and aerobic) over time during exercise.
• ATP-CP system is the primary energy source briefly before other systems take over.

Cardio Respiratory Response to Exercise

• Oxygen deficit: the difference between the oxygen consumed and the amount needed to sustain exercise.
• Steady-state oxygen consumption is the point where oxygen intake meets the demands of exercise.
• Oxygen debt, or EPOC (excess post-exercise oxygen consumption): the extra oxygen consumed after exercise to restore the body to its pre-exercise state.

Graded Exercise

• Graded exercise tests are used to measure oxygen uptake during varying levels of exercise.
• This involves gradually increasing the workload (e.g., treadmill speed, bike resistance) to observe oxygen uptake responses.

Fick Equation and VO2max

• The Fick equation relates VO2max to cardiac output and arterial-venous oxygen difference.
• VO2max = Cardiac Output x (a-vO2 diff)
• Cardiac output = Heart rate x Stroke volume

Cardiovascular Responses to GXT

• a-vO2 difference (arterio-venous oxygen difference): the difference in oxygen content between arterial and venous blood. This difference increases with exercise.

More Cardiovascular Responses to Exercise

• Heart rate increases with workload until it reaches its maximum (HRmax).
• Stroke volume (SV) initially increases with workload (up to 40-60% of maximal workload) and afterward remains relatively stable.
• Pulmonary ventilation (VE) linearly increases with workload until moderate exercise intensity (up to 50-80% maximal) with a more rapid increase approaching maximal exertion.
• Cardiac output increases with workload as heart rate and stroke volume both increase during exercise.

Blood Pressure Responses to Exercise

• Systolic Blood Pressure increases steadily with increased workload, while diastolic blood pressure may remain relatively stable or increase slightly.
• Dynamic systolic and diastolic pressures increase steadily throughout the exercise period, while static pressures exhibit a stable increase and decrease.

Assessing Exercise Responses

• Pre-exercise assessment should be taken in the exercise position for baseline values.
• During exercise measurements should be taken on each exercise intensity increase.
• Post-exercise assessment should be performed until stability.
• Some clinical parameters can be measured during exercise, and one such is rate pressure product (RPP), a product of heart rate and systolic blood pressure.

Selecting CRF Assessments

• Many assessments are used to determine CRF levels in both healthy and clinical populations.
• Various tests for CRF, such as maximal oxygen uptake (VO2max), submaximal oxygen uptake, step tests, and field tests (like the Astrand-Ryming or Queens tests) are available for implementation.
• Considerations when selecting a test include intensity, length and expense, personnel needed, required accuracy, the appropriateness of the type of exercise, and the participant's willingness. Avoid a one-size fits all approach.

Interpreting CRF Assessment Results

• Percentile tables indicate the performance and expected oxygen uptake (VO2max) by different age groups. Results are categorized as excellent, good, etc.

Metabolic Calculations

• METs (Metabolic Equivalents) are used to measure energy expenditure relative to body weight. One MET is equal to 3.5 ml of oxygen (O2) per kg of body weight per minute.
• Metabolic expenditure can be calculated using different activities, each with specified METs.

FITT-VP

• FITT-VP (Frequency, Intensity, Time, Type, Volume, Progression) is a framework for developing exercise programs.

Aerobic Exercise Recommendations

• The recommended frequency, intensity, and duration for aerobic exercise for most adults is outlined in a specific format.

Intensity Levels

• The relationship between volume and intensity of exercise has an inverse relationship. A higher volume often results in a lower intensity, and vice-versa. Different activities are categorized as light, moderate, or vigorous based on the intensity.

Principles of Training

• Progressive overload is a key principle in exercise training, meaning the training intensity has to regularly be increased.
• Reversibility relates to the principle that if the training stops, the improvement made is lost.
• Individual differences show that the same training intensity may have different effects on the body of different people based on individual variations.
• Training specificity shows that different training programs will elicit different results based on what is being trained.

Safe & Effective Exercises

• Various exercises, including walking, jogging, bicycling, swimming, and aerobic machines, have advantages and disadvantages.
• Consider factors like the equipment needed, environmental conditions, and safety precautions before choosing a form of exercise.

Interval Training for Mortality

• Wearable device-measured vigorous intermittent lifestyle physical activity may be associated with lower mortality rates.

Determining Exercise Intensity

• Various methods of determining exercise intensity may be used, taking into account factors like heart rate, oxygen uptake, and perceived exertion.

Abnormal Responses to Exercise

• General indications include onset of angina, significant changes in blood pressure during exercise, shortness of breath, or other symptoms that may indicate a need to stop exercise immediately.

Injury with CRF

• Intrinsic and extrinsic risk factors exist that may contribute to injury during exercise. Intrinsic risk factors include previous injuries, training errors, poor technique, and excessive intensity. Extrinsic risk factors include the type of equipment, footwear issues, weather conditions, and other variables.

Heat, Cold, or High Altitude on Exercise

• Extreme weather and high altitude can affect a person's physiological response to exercise by increasing heart rate.