“Inactivity is a fruitful cause of disease. Exercise quickens and equalizes the circulation of the blood, but in idleness the blood does not circulate freely, and the changes in it, so necessary to life and health, do not take place. The skin, too, becomes inactive. Impurities are not expelled as they would be if the circulation had been quickened by vigorous exercise, the skin kept in a healthy condition, and the lungs fed with plenty of pure, fresh air. This state of the system throws a double burden on the excretory organs, and disease is the result.” –The Ministry of Healing, p. 238

As we learned in a previous article, there are five components that must function at optimum levels for good body fitness; these include body composition, muscular strength, flexibility, muscular endurance, and cardiovascular endurance. Almost all fitness programs consist of exercises that focus on one or more of these components. A comprehensive fitness programme should encompass all five aspects of physical fitness. Concentrating only in one or two areas is not enough to maintain good physical fitness.

Before we begin, it would be remiss not to mention that a doctor’s approval is needed in some scenarios, before starting a fitness program. Some of these include: if you are a man over 45 or a woman over 55, being overweight, having high blood pressure, personal or family history of heart attack, high cholesterol, diabetes, cardiovascular disease, lung disease, you become dizzy with exertion, you feel pain or discomfort in your chest, jaw, neck, or arms during activity, you have not had a recent physical exam done by your doctor to ensure that you are in good health, or you have not been exercising regularly. If you are on regular medication, check with your doctor as to whether exercise will make the medication work differently or if it will change its side effects , or if your medication will affect the way your body reacts to exercise. Especially diabetics need to check with their doctors before starting an exercise routine, as exercise may lower blood sugar, and the medication doses that are prescribed may drop blood sugar to dangerously low levels.  Many diabetics who lose weight as part of an exercise program may be able to permanently reduce the doses and the amount of medication they take.

So, to go back our topic, how do we ensure that we our fitness program includes exercises that focus on all of these areas? To ensure that a fitness program includes all that we need for peak physical fitness, we need to incorporate three different categories of exercise into our program. These three categories are aerobic, anaerobic, and flexibility exercises. In this month’s article we will go into detail into the first of these categories—aerobic fitness.

AEROBIC FITNESS

Aerobic exercise, also known as cardiovascular exercise—“cardio” for short—or endurance activity, is the cornerstone of most fitness training programmes. The definition of aerobic means “with oxygen”. Therefore, when doing aerobic exercises, the body uses oxygen in order to create energy. Aerobic exercises address three components of physical fitness including cardiovascular endurance, muscular endurance, and body composition.

Aerobic-type exercises cause you to breathe faster and more deeply, maximizing the amount of oxygen that circulates in your blood. Oxygen, a necessary ingredient in creating energy, is taken up by all the cells in the body when we breathe. Glucose, the fuel needed to create energy, is also taken up by the cells; the process then takes place where the cells convert oxygen and glucose to ATP, or cellular energy.

When you are exercising your muscles must work harder which increases their demand for oxygen to produce energy. So, how does aerobic exercise improve oxygen flow to the muscles when they are working? To improve cardio fitness, aerobic exercise involves using the large muscles of the body. More blood is needed for the muscle cells to produce more energy, so the heart beats faster to send more oxygen to the muscles. Over time, when engaging in regular cardio exercises, the left ventricle (chamber) of the heart enlarges so that more blood can be pumped out to the body with each beat. The larger cavity can hold more blood, and pump out more blood per beat, even when you are resting. Therefore, the heart becomes much more efficient and does not need to beat as quickly to send the same amount of blood and thus oxygen to the muscles. The resting and working heart rate then drops, because each beat delivers a bigger volume of blood, therefore fewer beats are needed. This takes work off your heart, and which is why cardio exercise is recommended for heart health.

Also, when your heart works less to pump blood, the force on your arteries decreases, lowering your blood pressure. To maintain an overall lower blood pressure, you must exercise regularly. Once you stop exercising, blood pressure can rise again. Aerobic exercise also stimulates the production of new blood vessels. As more blood vessels are created, there are more places for blood to flow, which results in more efficient circulation. This also lowers blood pressure because the circulating blood travels within a larger network of blood vessels. New blood vessels also grow in the muscles to keep up with the increased demand for oxygen, thus making muscles even more effective in taking in oxygen to create energy. You will need less oxygen to produce the same effect in the muscles, and you will feel less out-of-breath when you breathe during exercise.

Lungs do not increase in size with exercise; however, the heart has a better ability to take in oxygen from the lungs, which increases the amount of oxygen available to the body. The better your aerobic fitness, the more your oxygen intake improves, and the more efficiently your heart, lungs and blood vessels transport oxygen throughout your body to the cells.  Aerobic exercise reduces levels of LDL (“bad” cholesterol), which clog the arteries and can trigger a heart attack. At the same time, exercise can raise levels of HDL (“good” cholesterol). HDL helps protect against a heart attack by carrying plaque out of the arteries. Because exercise burns calories, combined with a proper diet, many who are overweight can achieve a normal body composition.

Every cell of the body requires oxygen; therefore, aerobic fitness not only improves the function of the cells required for physical activity, but also every other cell of the body benefits from increased oxygen levels, e.g. brain cells, Overall, with more oxygen, we have more heart and muscle endurance, we have greater stamina and can do much more without getting tired. It is easier to perform routine physical tasks and also to rise to unexpected challenges. Thus, aerobic exercise not only benefits the physical health of the body, but improves quality of life in general.

AEROBIC EXERCISE

In order to improve cardiovascular endurance, the heart must beat at a certain rate per minute for improvement to take place. Once that level is achieved, the heart becomes more efficient in taking in oxygen to the body. The body needs the most oxygen when the large muscle groups are activated. Therefore, aerobic exercise involves movements that use the large muscles groups, as large amounts of oxygen are needed to be sent to the muscles to perform at their peak.

The way to identify whether the heart is working at a level to improve function is too determine how quickly the heart is pumping. The faster it pumps, the more oxygen is brought into the body. There is an easy way to calculate how quickly the heart must be going in order to improve fitness. First you must calculate the maximum heart rate that should occur while exercising. The maximum heart rate for men is 220 minus your age. For women it is 225 minus your age. The goal rate for exercising should be 70% of your maximum rate. When the heartbeat is faster than the 70% you are doing aerobic exercises. Let us take for example a 35-year-old male: (220-35=185) x 70%=130. Therefore, to improve cardiovascular fitness, his heart rate must remain above 130 for the length of the exercise session.

For the average person, the heart rate will be in the range of 120 to 130 beats per minute. You can determine your own heart rate by feeling for the vein on your wrist which extends behind your thumb. You can count how many beats there are in 15 seconds and multiply it by four. Many people also use fitness trackers which monitors heart rate.

Even moderate exercise benefits the cardiovascular system if the heart rate is maintained at the target level for at least 20 minutes, and minimum three times a week. However, many government health departments are now promoting daily exercise because of the obvious benefits to one’s health.

Aerobic exercise can either be low-impact (one foot always on the floor) or high-impact (both feet leave the floor). High impact is more jarring on the joints, but it also improves bone health more effectively. Because of other health conditions, many people cannot do high impact exercises. It doesn’t matter which one you do; both will improve cardiovascular and muscular endurance.

Examples of mild to moderate aerobic activities:

  • Rake leaves
  • Take a walk around the block
  • Play actively with the kids
  • Walk up the stairs instead of taking the elevator
  • Mow the lawn
  • Park your car a little farther away from your destination
  • Shovelling snow
  • Vacuuming

Examples of higher intensity aerobic activities:

  • Brisk walking
  • Jumping rope
  • Jogging
  • Bicycling
  • Swimming
  • Aerobic classes
  • Racket sports
  • Team sports
  • Rowing
  • Ice or roller-skating
  • Cross-country or downhill skiing
  • Using aerobic equipment (i.e., treadmill, stationary bike)

“Walking, in all cases where it is possible, is the best remedy for diseased bodies, because in this exercise all the organs of the body are brought into use. Many who depend upon the movement cure could accomplish more for themselves by muscular exercise than the movements can do for them. In some cases, want of exercise causes the bowels and muscles to become enfeebled and shrunken, and these organs that have become enfeebled for want of use will be strengthened by exercise. There is no exercise that can take the place of walking. By it the circulation of the blood is greatly improved.” –Testimonies for the Church, vol. 3, p. 78

Breathing properly when exercising is very important. Often people breathe too fast, too slow, too deeply, or too shallow. Sometimes people inhale and exhale at the wrong times; this can affect the exercise and how well you perform it. As we go about our daily lives, breathing comes naturally and we don’t need to think about it. Our body needs oxygen so we automatically inhale, and when our body needs to get rid of carbon dioxide (waste product produced when muscles use oxygen), we automatically exhale. However, when not exerting themselves, most people tend to breathe from the upper part of their lungs, and only use 10–15% of their full lung capacity. When we begin to exercise, our body needs more oxygen, and it needs to get rid of more carbon dioxide, thus we begin to breathe more quickly. However, just an increase in rate, yet still breathing only from the upper area of the lungs can make one feel dizzy, as not enough oxygen is actually getting into the body.

Diaphragmatic breathing or “belly” breathing, allows for deeper, fuller breaths, with increased oxygen intake. This can be practiced even before engaging in exercise. Your breathing should be deep, rhythmical, and relaxed. To breathe from your diaphragm, first relax your abdominal muscles. Keeping them too tight will restrict your ability to breathe deeply. When breathing, focus on your belly. You are breathing deeply when your belly goes in and out, instead of your shoulders rising and falling. The amount of time that it takes for you to inhale should be the same amount of time that it takes for you to exhale. As the exercise increases in intensity, breathing can become quicker, but should still remain deep and from the diaphragm. Breathing can be done either through the nose or through the mouth; some people find that they can get more air in when breathing through their mouth during intense exercise. Often people will breathe in pattern with the exercises they are performing. For example, when jogging, take a breath in every 2–3 steps, and then exhale every 2–3 steps. The main thing is to find a breathing pattern that works for you, that you feel comfortable with.

For an effective aerobic exercise session, it should include a warm-up period prior to the activity and a cooling down period after the activity. These periods generally involve doing your activity more slowly and at a lower intensity. For example, before a brisk walk, walk slowly for 5–10 minutes. At the end of your walk, do the same thing for a cool down. A warm-up prepares your body for the activity. It slowly fires up your cardiovascular system by raising your body temperature and increasing blood flow to your muscles. A warm-up period may also help reduce muscle soreness and lessen your risk of injury. Cooling down after exercise allows for a gradual recovery of pre-exercise heart rate and blood pressure.

“The greatest benefit is not gained from exercise that is taken as play or exercise merely. There is some benefit derived from being in the fresh air and also from the exercise of the muscles; but let the same amount of energy be given to the performance of helpful duties, and the benefit will be greater, and a feeling of satisfaction will be realized; for such exercise carries with it the sense of helpfulness and the approval of conscience for duty well done.” –The Adventist Home, p. 506

Next Month: Anaerobic Exercises and Flexibility Training.