Chapter 3 – Cardiorespiratory Fitness
Cardiorespiratory Systems
Imagine for a moment climbing to the top of Mt. Everest, a challenging feat very few have accomplished. In the process, you gradually ascend from base camp, which sits at about 17,500 feet above sea level, to the peak at over 29,000 feet. At this elevation, the pressure of oxygen is so low, you struggle to take in a satisfying breath. Although you strive to breathe deeply, you are unable to get enough air. Your heart rate increases and you might even develop nausea and a headache. Unless your body has a chance to acclimate itself to higher elevations or you gain access to supplemental oxygen, your symptoms will persist or worsen.
These are the sensations many people with cardiovascular or respiratory illnesses, such as asthma, chronic bronchitis, or mild cardiovascular disease, experience on a daily basis. Climbing up a flight of steps may leave them gasping for air, as would walking briskly or even breathing in cold air. Regardless of the cause, being unable to take in sufficient air can create a sense of panic and cause serious physical discomfort.
From this example you may feel an appreciation for the simple act of breathing and ensuing satisfaction that comes with each life-sustaining breath. For most people, unless they engage in strenuous physical activity sufficient to get them breathing hard, their cardiovascular and respiratory system (heart, blood vessels, and lungs) operates efficiently enough to go relatively unnoticed. However, does that mean their cardiorespiratory system is functioning at optimal capacity? Or, could it be operating at a minimum level and experiencing problems that go undetected? This chapter defines cardiorespiratory fitness, examines the benefits of a healthy cardiorespiratory system, and explores how to effectively assess and improve the cardiorespiratory system.
The Benefits of Good Cardiorespiratory Health
Increased Life Span – Cardiorespiratory fitness is an essential part of maintaining your overall health. According to studies conducted within the United States, people who had poor levels of cardio fitness were far more likely to die from numerous causes (twice as likely), than those who were cardio-fit.
Decreased Risk of Diabetes – Lack of aerobic fitness in individuals can prompt negative changes in the metabolic system that, in turn, may lead to type 2 diabetes. Experts maintain that by engaging in regular cardiorespiratory activity, you can improve your glucose regulation, and insulin sensitivity, thereby reducing your diabetes risk.
Better Bone Health – By engaging in moderate aerobic activities such as jogging or swimming for up to 150 minutes every week, you may be able to avoid suffering from various bone complications, including hip fractures. According to the centers for disease control and prevention, exercising in such a way helps to maintain the strength of your bones by slowing the rate at which bone density is lost.
Decreased Risk of Metabolic Syndrome – Regular cardiovascular workouts can be helpful in preventing metabolic syndrome, according to the CDC. (Metabolic syndrome can be recognized as a combination of medical conditions including excess waist fat, high blood pressure and high levels of cholesterol and blood sugar. The condition can put you at risk of developing diabetes, stroke and heart disease)
Promotes Weight Loss – Cardiorespiratory fitness can help you burn anywhere up to 872 calories an hour, depending on the intensity of the activity or sport, and your initial body weight.
Supports Strength and Other Training – An efficient cardiovascular system supports the demands of others systems during and after training to maximize training benefits.
