Aerobic Exercise has very beneficial effects on the body's physiological processes and the Cardiovascular system which consist of two components: 1. The heart and 2. the vasculature such as blood vessels. There are various activities that can get your heart rate up to a submaximal level for sustained periods of time that qualify as aerobic activities. For example, an aerobic step class, fast pace walking, and running just to name a few.
There are various sources from which you can get this information. For this page, I reference the NSCA's (National Strength & Conditioning Association) Essentials of Personal Training by Roger W. Earle & Thomas R. Baechle as an excellent source for this information.
The Heart adapts well to stress that is placed upon it. The changes that happen due to engaging in aerobic training will give you a life time of benefits. During exercise your heart is stimulated to speed up in order to supply oxygen through the blood supply to parts of the body where it is needed. Your sympathetic nervous system and parasympathetic nervous system release neurotransmitters (epinephrine, norepinephrine, and acetylcholine). Because of these effects from the nervous system, the heart rate (HR) and stroke volume (SV) increase during exercise. This is normal and to be expected.
As a result of the heart getting a workout by being stimulated to beat at a higher heart rate, it adapts to the challenges being put on it and as a result becomes stronger and more efficient at pumping blood throughout your body. As a result of being conditioned to perform at higher intensity levels for sustained periods, the heart will then beat much more efficiently while the body is at rest or while engaging in regular daily activities. The result is you have more energy and every day tasks become much easier for you to perform. You get to the point to where you can perform higher intensity work with a lower heart rate as compared to someone who is not conditioned and not fit.
As a result of long term aerobic training the size of the chambers of the heart increases approximately 40 % overall and is the main reason the stroke volume and efficiency of the heart is higher and superior in people who undertake aerobic endurance training. Their body is able to utilize oxygen better and get rid of carbon monoxide at a higher rate. The overall size of the heart can increase with the left ventricular wall becoming thicker. These changes in the size of the heart resulting from aerobic training occur regardless of age or gender.
Respiratory Changes - The body is able to utilize oxygen better and this is true of the respiratory system as well. Because the need to supply oxygen, the respiration rate (i.e. pulmonary ventilation) increases as exercise intensity increases. long term effects are increased lung volume, carrying capacity of the blood, and diffusion ability of the lungs.
One of the most noticeable changes that are associated with long-term aerobic exercise is a decreased resting and submaximal exercise heart rate.
* A training induced reduction in heart rate has been shown to occur with training in as little as two weeks, but some studies have shown the reduction can take as many as 10 weeks.
Another adaptation the cardiovascular system makes due to aerobic exercise is an increased blood volume. This is because of an increase in the water component of blood (plasma), as well as an increase in hemoglobin, the oxygen-carrying component of your blood. The larger blood volume will lead to a greater stroke volume during rest. Again this means your heart is stronger and works more efficiently at rest as compared to someone who is not fit.
The adaptation of the vasculature both coronary and peripheral, to aerobic exercise is, for the most part, one of increased density. The increased in the density of the capillary beds, allows for better diffusion of oxygen and other metabolites as well. This permits better uptake of oxygen at the muscle level.
Improved Metabolic Changes - The energy systems of the body become more efficient at producing energy as a result of aerobic training. The use of substances in the body such as fat and carbohydrates that allows for greater energy production also becomes a more efficient process. You become a better calorie burning machine in simple terms.
Improved glycogen storage in the muscles as a result of aerobic training and there is an increased concentration of available substrates such as glycogen for utilization resulting in a increased and prolonged workout time before you reach exhaustion or fatigue threshold also known as "lactic-acid threshold."
Body Composition - One of the biggest reasons people begin an aerobic training program is because they want to lose excess body weight and fat. The positive adaptations to aerobic exercise is a change in body composition. Often when a reduction in body fat is advised, aerobic exercise is recommended. Currently the recommendation is for sedentary people to get approximately 20 to 30 minutes of moderate exercise a day. This could be a brisk walk. One of the most obvious changes with such a regimen is a reduction in fat mass.
The Pancreas - People with metabolic problems such as diabetes type 1 and type 2 who are currently controlling their blood glucose levels through diet and medication and have been medically cleared by their medical doctor to participate in an exercise aerobic training program can benefit from aerobic activity. The pancreas is the endocrine gland that plays the biggest role in metabolism because it produces and releases insulin and glucagon. Both of these are necessary to uptake or release glucose, which is vitally important to the survival of the body. Single bouts of high-intensity aerobic exercise has been shown to increase the sensitivity of insulin and stimulates insulin-mediated glucose uptake in non-insulin dependent diabetes mellitus and also has been shown to increase insulin-stimulated whole-body glucose uptake for up to 48 hours post exercise. Long term aerobic training has also been shown to have a positive effect on insulin secretion. Trained individuals have an increased sensitivity to insulin and an increase in insulin responsiveness.
As you can see there are many ways the human body adapts to aerobic training in regard to the cardiovascular system. Cardiovascular endurance training or also called aerobic training should be a part of everyone's exercise program. The degree of intensity and duration of training bouts will vary from individual to individual based on fitness level, previous training history, and fitness goals. Whether you are walking 30 minutes a day, doing step aerobic classes, or running 10ks you the benefits will be great to your health and overall energy level.
For more information about cardiovascular training/Aerobic Training please feel free to e-mail me or contact me through this website.
