Chapter 3 - Cardiorespiratory Fitness Assessments, Exercise and Training - PDF

Cardiorespiratory Fitness Assessments and Exercise Programming for Apparently Healthy Participants What is C R F ? ? ? → The ability of the circulatory & respiratory systems to supply oxygen to the muscles to perform PA (VO2max = CRF) VO2 is a composite of how well you do three...

Cardiorespiratory Fitness Assessments and Exercise Programming for Apparently Healthy Participants What is C R F ? ? ? → The ability of the circulatory & respiratory systems to supply oxygen to the muscles to perform PA (VO2max = CRF) VO2 is a composite of how well you do three things 1. Get oxygen into the lungs (consumption) - pulmonary 2. Move RBCs to active skeletal muscle (transport) 3. Extract oxygen from RBC within active skeletal muscle & produce ATP (utilization) High CRF is associated with health benefits & reduced risk of CVD You have a high VO2 b/c your transport & utilization systems are good A dose response relationship exists between exercise & reductions in chronic disease If you improve one of the three systems, VO2 will reflect it ACSM-EP primary role is to provide the development & maintenance of CRF! Anatomy & Physiology: should be a review Heart Chambers: Atria: upper chambers (left and right) Ventricles: lower chambers (left and right) Left Ventricle—Responsible for driving blood from heart through the vasculature (SV) stroke volume (SV): the amount of blood Vasculature ejected from the left ventricle to the systemic circuit Veins & venules: carry deoxygenated blood Arteries & arterioles: carry oxygenated blood Capillaries: responsible for gas & nutrient exchange Energy Production for Muscles ATP is produced through one of three metabolic pathways Creatine phosphate is the most immediate source of ATP production. Creatine Phosphate (CP) Immediate source of ATP & lasts ~10 seconds Anaerobic Glycolysis Fast source of ATP & lasts ~90 seconds Oxidative System Slower source of ATP & lasts as long as oxygen is available Requires oxygen to facilitate the Kreb’s Cycle & Electron Transport Chain  Cardio Respiratory Response to Exercise: Oxygen Kinetics Single-Intensity Exercise VO2 increases at the onset of exercise until achieving steady state and declines post-exercise Oxygen Deficit: slow rise in VO2 after starting exercise Oxygen Debt: slow decrease in VO2 after stopping exercise Rapid achievement of steady state indicates higher fitness oxygen debt = make ATP again EPOC (Excess post-exercise oxygen consumption) “afterburn” = 1. Re-phosphorylation of creatine and ADP 2. Catecholamines 3. *Temperature* Graded Exercise used in many settings to determine baseline fitness and relevant health risks "graded" - the intensity increases Graded-Intensity Exercise Max VO2: highest VO2 achieved during a graded exercise test Higher VO2max indicates a higher level of aerobic training and fitness VO2max Fick Equation: allow for determination of VO2max VO2max = Cardiac Outputmax ×(a-vO2Δ diff max) Cardiac Output = HR x Stroke Volume  a measure of the amount of oxygen taken up by the working muscles from the arterial blood reflects the difference in oxygen Cardiovascular Responses to GXT content between the arterial and the venous blood. 1. What is a-vO2Δ??? More Cardiovascular responses to exercise… Heart Rate: increases with workload until HRmax is reached → (220-age) Stroke Volume: increases with workload initially (up to 40- 60% max) with little change later in a GXT As SV increases with training, resting heart rate does what? decreases Cardiac Output: ? HR x SV ; also increases Pulmonary Ventilation (VE) linearly increases with workload through moderate intensity (up to ~50-80% max) with more rapid increases near max exertion Blood Pressure Responses to e x e r c i s e just as cardiac output increases linearly with Systolic Blood Pressure (SBP): increases with increased workload increasing workload, so does SBP Diastolic Blood Pressure (DBP): remains relatively stable with increased workload; thanks vasodilation Total Peripheral Resistance (TPR): normally decreases modestly with increased workload Mean Arterial Pressure (MAP): increases with increased workload MAP = DBP + 0.33(SBP – DBP) If we know the responses, when/what should we assess?? Pre-Exercise: assessed in the exercise position During Exercise: assessed at each exercise intensity Post-Exercise: until stability -pre-ex. until it returns to levels Rate Pressure Product: an assessment of overall myocardial demand of exercise derived from HR and SBP Selecting Appropriate CRF Assessments for Healthy Populations Regularly performed in both healthy & clinical populations….why? don't spend time going into depth! (steady-state) Selecting the Appropriate CRF Assessment Primary Considerations Intensity, length, & expense of the test Type & number of personnel needed Equipment & facilities needed Physician supervision needs & safety concerns Required accuracy of results Appropriateness of mode of exercise Willingness of the participant to perform the test (participant motivation) AVOID “ONE-SIZE-FITS-ALL” APPROACH Interpreting results of C R F Assessments A primary role of the EP-C is to provide an interpretation of testing results that are understandable and useful for the client Did they have a normal response? What is limiting? Compare results to established standards: Criterion-Referenced: classification based on group categories (excellent, needs improvement, etc.) Normative: classification based on percentile rankings based on specific demographic variables  Metabolic Calculations A MET = metabolic equivalent of task A ratio of the rate at which an individual expends energy relative to their body weight What would be good units for this?? 1 MET = 3.5 ml of O2/kg of bw/min Think about the definition of a MET one more time… 1. A rate (min) 2. Expends energy (mL: 1 L of O2 = 5 kcal) 3. Relative to bw 4. 1 = 3.5 ml of O2/kg of bw/min (aka the amount of energy you expend sitting at your desk right now; sedentary) Copyright © 2019 ACSM All Rights Reserved Metabolic Calculations Continued….  FITT-VP What is this?? FITT-VP – provides the framework to establish an exercise prescription program F = Frequency deals with aerobic exercise I = Intensity T = Time (or duration) T = Type (or mode) KNOW THIS! - test question V = Volume (or amount) P = Progression (or advancement) FITT-VP Continued…. Principles of Training 1. Progressive Overload: reflects need for exercise to be greater than accustomed to induce adaptation (i.e. more than yesterday) To improve CRF, the individual must exercise at a level greater than accustomed to induce adaptation. 2. Reversibility: represents the opposite of the overload principle and reflects the idea of ‘use it or lose it’ once cardiorespiratory training is decreased or stopped for a significant period (2–4 wk), previous improvements will reverse and decrease 3. Individual Differences: recognizes that the same stimulus can produce very different responses within individuals. Genetic factors often considered to play the biggest role. 4. Specificity: states that specific exercise elicits specific adaptations, creating specific training effects. (i.e. if you want to get good at sprinting, sprint.) also known as the SAID (specific adaptations to imposed demands) principle dependent on the type and mode of exercise Safe & Effective Exercises Designed to Enhance CRF Interval Training Determining Exercise Intensity Options range from direct measurements to more subjective approaches HRR Method Peak HR Method Peak VO2 Method Peak MET Method VO2 Reserve Method Talk Test Method Perceived Exertion Method - Borg Scale Abnormal Responses to Exercise Be able to select one or two in a MC question! Injury with CRF Effects of Heat, Cold, or High Altitude on the Physiological Response to Exercise The percentage of oxygen (20.93%) in dry air is the same at all elevations.