7 C H A P T E R Mark A. Williams Cardiovascular and Respiratory Anatomy and Physiology Responses to Exercise
Chapter Outline Cardiovascular anatomy and physiology Respiratory anatomy and physiology Cardiovascular and respiratory responses to acute exercise Cardiovascular and respiratory responses to aerobic and resistance exercise training External influences on cardiorespiratory response
Arterial and Venous Components of the Circulatory System
T he cardiovascular system transports nutrients and removes waste products while helping to maintain the environment for all the body’s functions. The blood transports oxygen from the lungs to the tissues for use in cellular metabolism; blood also transports carbon dioxide—the most abundant by-product of metabolism—from the tissues to the lungs, where it is removed from the body.
Blood Pressures in Different Portions of the Circulatory System
A cute aerobic exercise results in increased cardiac output, stroke volume, heart rate, oxygen uptake, systolic blood pressure, and blood flow to active muscles and a decrease in diastolic blood pressure. Resistance exercise with low intensity and high volume generally results in similar responses, some to a lesser degree.
A cute bouts of high-intensity, low-volume resistance exercise result in increased heart rate and increased diastolic and systolic blood pressure but no change in oxygen uptake, no change or a slight increase in cardiac output, and no change or a slight decrease in stroke volume.
Distribution of Tidal Volume in a Healthy Subject at Rest
D uring aerobic exercise, large amounts of oxygen diffuse from the capillaries into the tissues, increased levels of carbon dioxide move from the blood into the alveoli, and minute ventilation increases to maintain appropriate alveolar concentrations of these gases.
Pressure Gradients for Gas Transfer in the Body at Rest
A erobic exercise training results in increased maximal cardiac output and maximal oxygen uptake, slower resting heart rate, increased capillarization, improved ventilation efficiency, increased oxygen extraction, and OBLA occurring at a higher percentage of aerobic capacity.
R esistance training is not effective in improving maximal oxygen uptake. Training with high intensity and low volume results in no change or a decrease in capillary density, no known change in ventilation, no improvement in oxygen extraction, and very high blood lactate concentrations. Conversely, low-intensity, high-volume training may increase capillarization and improve oxygen extraction.