Chapter 15. Improving Cardiovascular Endurance

At the completion of this chapter, the reader will be able to:

1. Explain the importance of cardiovascular endurance in the overall health of an individual.

2. Describe the physiology of the cardiovascular system.

3. Describe the various types of energy and how each is generated.

4. Explain how the various muscle types are involved with endurance and aerobic activities.

5. Outline the precautions with aerobic conditioning.

6. Discuss the various methods by which aerobic conditioning can be enhanced through a rehabilitation program.

Physical activity has been defined as “any bodily movement produced by skeletal muscles that results in energy expenditure.”1 When a person undertakes work or exercise, a number of body systems adapt to the demands of the required tasks, particularly the cardiorespiratory and neuromuscular systems.2 The maximum work capacity of the cardiorespiratory system is a factor of the maximal amount of oxygen that can be taken in and used by the body, or VO2max, whereas the capacity of the neuromuscular system is a factor of the maximum tension that can be developed by the working muscle, or muscles—the maximal voluntary contraction. Assessment of the cardiovascular system provides the clinician with the justification for monitoring or not monitoring activities during a patient's rehabilitation or providing modifications in the exercise prescription.3

Whenever possible, the clinician should address the impact on the patient resulting from the loss of physical activity. This loss of activity affects both the cardiovascular and the musculoskeletal systems and can occur very rapidly. Thus, it is important that the rehabilitation program includes exercises that maintain, or improve, the patient's cardiovascular endurance, while monitoring safety concerns. If our sedentary society is to change to one that is more physically active, clinicians must play their role in communicating to their patients the amounts and types of physical activity that are needed to prevent disease and promote health, because patients respect their advice.4,5 Patients should be routinely counseled to adopt and maintain regular physical activity. Inadequate reimbursement, limited knowledge of the benefits of physical activity, and a lack of training in community physical activity counseling are barriers to achieving these goals. While policy makers work to improve reimbursement for preventive services, clinicians should develop effective ways to teach physical activity counseling.5 The personal physical activity practices of health professionals should not be overlooked. Health professionals should be physically active, not only to benefit their own health but also to make more credible their endorsement of an active lifestyle.5

According to the Department of Health and Human Services, physical fitness is a set of attributes a person has in regards to his/her ability to perform physical activities that require aerobic fitness, endurance, strength, or flexibility and is determined by a combination of regular activity and genetically inherited ability.6 Although commonly associated with the state of the cardiorespiratory system, which includes the ability to perform work or participate in activity over time ...