17A. Aerobic Benefits and Methods

As America changed from an agrarian society last century to an urban technological society this century, the nature of American disease changed. In 1900 heart disease was the tenth most common cause of deaths in America. In 1996 heart disease was the first most common cause of deaths in America. Heart disease has a number of predisposing conditions (diet, stress, physical conditioning, drugs) but one of the major reasons for the increase in heart disease recently is that Americans have become very sedentary. Americans don’t walk to town, church or school any more, they ride. They don’t harvest corn any more, they open a can they purchased at the grocery store where they drove in a comfortable car. Anymore they don’t even want to get up and change the channel on the TV; they have a remote control device. Consequently, Americans don’t get much exercise compared to the American at the turn of the century.

Few of us have active jobs, that is, jobs where we walk around nearly constantly or have the energy expenditure close to that of walking eight hours a day. Most of us have sedentary jobs sitting behind desks, getting up perhaps four times an hour to go get something. Karate training twice a week gives us a fair amount of exercise, but probably not enough to prevent heart disease and keep us in robust physical health. We need just a little more than twice a week.

By instituting one to two more practice sessions of an hour duration per week we reap far greater benefits for robust physical health. I recommend that students at the dojo get together with other students from the dojo at prearranged times for a training together. Practice basics, kata, prearranged kumite for an hour or so. Assess your heart rate and see if you are nearing a target heart rate (discussed later in this e-mail). Most of all enjoy your training. By doing this just once or twice a week in addition to regular classes you will notice an improvement in your physical condition, karate proficiency, and mental outlook (yes, physical activity often improves mental outlook!!!).

If you want to see results quickly then you can add an additional aerobic training to your regular routine. This presupposes that you do not have any disease condition which would prevent this kind of activity. If you have any I suggest you seek the opinion of a physician prior to beginning any exercise program.

The main target for aerobic training is the cardiovascular system (heart and blood vessels). The cardiovascular system delivers blood to the cells of the body. The heart increases its blood delivery on demand from the cells of the body thru certain receptors in the neck. Exercise causes the muscle cells to need more blood. Receptors sense that the increased blood flow is needed and the heart rate increases. The more exercise the more the heart must pump blood to the cells, that is, until the heart cannot pump blood any faster (maximum heart rate).

The cardiovascular system, i.e., the heart and blood vessels, deliver blood containing oxygen to the cells of the body. During rest the heart generally pumps about five liters of blood per minute to the cells of the body. As exercise begins the five liters per minute is increased upward to six, then seven liters per minute depending on the body’s need. The average person who doesn’t do much exercise will top-out at 10-15 liters per minute or maybe a little more. It may go up to 25 to 35 liters per minute in a well-trained athlete. The heart just can’t pump more blood each minute than the maximum heart rate for any individual because it just has an upper limit. As the upper limit is approached the body becomes stressed as seen in rapid, labored breathing, the sense of impending exhaustion, and finally exhaustion. This upper limit can be increased over time, however, by regular aerobic conditioning, a worthy goal especially for a martial artist.

Some exercises such as walking, running, bicycle riding, hiking, swimming and continuous volley racquetball require continuous or nearly continuous large body movement. These types of activities cause the heart rate to increase usually to 60-80% of the maximum heart rate it can efficiently pump. Regularly exercising the heart by running the heart rate to 60-80% of the maximum heart rate over a period of months causes the heart to pump more blood with each heartbeat, a healthy condition and one known as the training effect. As the amount of blood pumped each heartbeat increases the same rate causes more blood to be pumped in a minute. An individual with this type of enlarged heart can exercise more with less fatigue, i.e., this individual has more endurance.

Cardiovascular benefit develops when sufficient intensity, duration and frequency of the activity is reached. It really doesn’t matter if a person does just walking, just running, just swimming, or whether he/she mixes and matches activities. Doing karate training is just as good if it meets the intensity, duration and frequency requirements. So let’s look at these requirements.

Intensity: The intensity of the aerobic activity is determined by the heart rate maintained during the exercise session. The goal is to reach a reasonable target heart rate. To determine the target heart rate I will give you a very simple method:

Maximum heart rate = 220 – your age Target heart rate = maximum heart rate X intensity factor

The intensity factor for best training effect is between 0.6 to 0.9. I recommend that those beginning aerobic condition start with an intensity factor of 0.6 and gradually work up to a level around 0.75. Going higher than 0.8 is very hard on the body and, although it leads to fast gains in aerobic conditioning, it also leads to many more strains, sprains and body injuries.

So let’s take me as an example: I am 52 years old. Say I want to exercise at 75% of my maximum heart rate. What would be my target heart rate for this intensity of aerobic exercise?

Maximum heart rate = 220 – my age = 220 – 52 = 168 beats per minute Target heart rate at 75% IF = 168 X 0.75 = 126 beats per minute

So to get my target (75% IF) I need to get my heart rate up to 126 beats per minute. How? It is rather unimportant. I may get it during karate training, on a run, on a fast walk, swimming, playing continuous racquetball, riding a bicycle, or doing an aerobics-dance class. The activity is not as important as maintaining the target heart rate during the entire activity. (The only caution about changing activities is that your muscles may be trained only for running if you have been doing a running program for a year. If you go to an aerobics-dance class your heart may take the activity but you may find your muscles fatiguing and being prone to injury because of the new activity and its use of different muscle groups.)

How to measure your heart rate during exercise is a major concern for some people. If you want a technological solution you might consider purchasing a cheap ($150) exercise cardiac rate monitor. They are available at sporting goods stores everywhere. If you aren’t one of those technological types you might measure your heart rate during a brief rest-period for 6 seconds then multiply the counts by 10. Say that you have a break in a karate class. You measure your heart rate for 6 seconds as 14. Multiplying 14 by 10 give a rate of 140 beats per minute approximately. If you are my age you are training at 83% of your maximum heart rate. (220-52 = 168. [140/168] X100 = 83) With a sustained heart rate of 140 and an 83% of maximum heart rate intensity factor you are getting a great cardiovascular training effect and your heart will get strong and robust. In reality, however, it is difficult to maintain 83% IF during an entire karate class unless you train with a Sensei like Sensei James Miyaji. Other instructors often have other agenda and talk sometimes allowing the heart rate to fall to near resting rate before beginning again. You do get benefit from this but it is not as good of aerobic training as when you maintain your heart rate at target rates for the entire duration recommended.

Another way to “measure” the intensity of your training is the dyspnea index. At up to about 60% IF you can talk with a partner in complete sentences with ease. There is no shortness of breath. At 70% you can talk with a partner in phrases but it is very difficult to talk for any length in complete sentences. At 80% it is difficult to talk in phrases but the conversation usually follows single words or short phrases. At 90% one only looks at the other and doesn’t speak at all unless forced. If using the dyspnea index it is best to strive for 70% where you can talk in phrases rather than 60% because it is difficult to know the difference between 50% and poor training effect and 60% where the training effect begins to improve. At both 50% and 60% one can talk in full sentences.

No matter how you measure the intensity of your aerobic training it is important to remember that it is your target heart rate (220-age) X (intensity factor) which you are striving for. You can use a technological device, a rest-period to count pulse rate, or a dyspnea index to approximate intensity. The importance is to gain sufficient intensity to reach a reasonable target heart rate. Then enjoy your exercise so that you will exercise again.

Next is duration. The duration of the target heart rate needs to be no less than 20 minutes and, most sources state, probably 30 minutes is far better. It is important to note that the target heart rate is to be reached and maintained during the entire session, not just sporadically reaching the level and then dropping off. Some people train for hours at low target heart rate intensities, as often occurs in hiking and backpacking. Other people stick straight to a 20-30 minute workout. Whatever your choice is just make sure you get your target heart rate up for your whole workout; don’t cheat yourself. (I personally like to get my target heart rate up and maintain it for an hour.)

Next is frequency. The frequency of the aerobic sessions depends on the intensity factor and the duration of exercise of the sessions. If a person goes all out for an intensity factor of 0.9 for 60 minute sessions then it is wise not to exercise 7 days per week. Three days per week is sufficient, four is best, five may be exceedingly hard to maintain without injury or prolonged fatigue at a 90% IF. On the other hand if the person chooses an intensity factor of 0.6 for 20 minutes sessions it is perfectly good to exercise 7 days per week (note that at this low intensity factor and short duration three days per week is really insufficient).

It is unimportant how one maintains the target heart rate. Swim today, walk tomorrow, karate the third day, run the next day, bicycle the day after. It is all beneficial if you reach and maintain your target heart rate for the proper duration and achieve the proper frequency.

Then the heart will become a more robust pump. It will increase its maximum output from say 15 liters per minute to 16, 17, 18. The arteries in it will become larger and more numerous. The cholesterol deposits (if any) will begin to dissolve. The “good” cholesterol will replace the “bad” cholesterol. The arteries in the muscles will increase in size and number. The capillary beds will become more profuse. The person will be able to endure rigorous training and keep up with the kids.

In addition, there are benefits in personal outlook on life. The mood becomes elevated, the quality of life often improves, and the person just seems happier. A mixed program in aerobic training is not essential but it allows for a more overall and well-rounded musculo-skeletal health. Running develops the legs. Bicycling develops different muscles than running. Swimming develops the trunk. Aerobic dance aims at an overall light stimulation. Mixing and matching activities which YOU like gives you choice and control while giving you the training your body requires. Just remember to get the correct intensity, duration and frequency.