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Cardiorespiratory Fitness Assessment. Chapter 4 - Heyward Chapter 4 - ACSM. Definition. Cardiorespiratory Fitness: The ability to perform large muscle, dynamic, moderate-intensity exercise for prolonged periods of time Dependent upon the “fitness” of the: respiratory system
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Cardiorespiratory Fitness Assessment Chapter 4 - Heyward Chapter 4 - ACSM
Definition • Cardiorespiratory Fitness: • The ability to perform large muscle, dynamic, moderate-intensity exercise for prolonged periods of time • Dependent upon the “fitness” of the: • respiratory system • cardiovascular system • skeletal muscles
Importance of CR Fitness • Deconditioned individuals have a higher risk of premature death than conditioned individuals • Increasing CR fitness is associated with reductions in all-cause mortality • High CR fitness generally means the individual performs physical activity, which is associated with health benefits
VO2max • Single best measure of cardiorespiratory fitness • VO2max= COmax X a-vO2 differencemax
Assessment of CR Fitness Assessing VO2max (aerobic capacity) Direct Measurement Estimation Maximal GXT Submax/Maximal GXT Protocol?? Protocol??
Assessment of CR Fitness Assessing VO2max (aerobic capacity) Direct Measurement Estimation Maximal GXT Submax/Maximal GXT
Direct Assessment of VO2max • Direct Measurement = open-circuit spirometry (maximal) • measurement of respiratory gases, ventilation • laboratory procedure • Requires maximal graded exercise test (GXT) • requires experienced personnel • requires calibration
Graded Exercise Test (GXT) • Multistage, incremented test • Stages are between 2-3 minutes • HR, RPE, BP measured • Progressive up to a pre-determined end point: • Exhaustion (max) • Achievement of desired HR • See GXT procedures, p. 52 Heyward
Assessment of CR Fitness Assessing VO2max (aerobic capacity) Direct Measurement Estimation Maximal GXT Submax/Maximal GXT
Estimation of VO2max • Estimation • Submaximal or maximal tests • respiratory gases not measured • lab or field tests - validated against gold standard
Submaximal Tests • Uses HR at one or more submaximal intensities to ESTIMATE VO2max • Based on several assumptions (p. 68 ACSM) • linear relationship between HR and VO2 with increasing exercise intensity or power output • steady-state HR is reached • must control factors that might alter HR response • assumes a max HR based on age (10-15% error)
Using Submax HRs to Predict Maximal To increase accuracy, these HRs must be steady-state and not be affected by outside factors
Extrapolation Lines are extrapolated to PREDICTED HRmax. There is error here.
Submaximal Testing to Estimate VO2max • General Procedures – p. 71 ACSM • Estimating VO2max – p. 75 ACSM • Cycle ergometer tests • work rate = kgm.min-1 • Astrand-Rhyming (single-stage) • YMCA (GXT)