Heart Rate Training Article

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Heart Rate Training

The training effect is considered the product of frequency, duration, and intensity of exercise. High intensity activities tend to be brief, as in anaerobic (energy produced without additional oxygen consumption ), and low intensity activities, tend to be prolonged as in aerobic (energy output associated with an increase in oxygen consumption). Training therefore can be as general or as specific as is desired, given the possible combination of the first four components. Certainly, the key to a good exercise program is the selection of activities that the individual enjoys and will do often enough, long enough and at an intensity sufficient to produce a training effect. For the average person aerobic endurance is the most important objective of any exercise program followed by strength, muscular endurance, and flexibility. Fortunately, with the proper selection of activities all of these objectives can be obtained.

The intensity of exercise is the most critical factor in an exercise program, although it is a relative term. Duration and frequency, being absolute values, can be the same for persons differing greatly in fitness levels. The intensity of an activity is the energy required to do that activity relative to the maximal amount of energy that can be provided aerobically. Intensity can be measured most precisely by an exercise stress test, but even without a test it is possible to give general guidelines in the form of a Training Heart Rate Range. Exercise physiologists have clearly shown that there is relationship between an individuals heart rate and their ability to obtain a certain level of exercise intensity.

Synonyms for the exercise heart rate, are training heart rate or target heart rate. You can determine your resting heart rate by simply determining your pulse while at rest. The radial pulse and the carotid are the two most frequently sites chosen to determine the heart rate. Two fingers should always be used for the assessment not the thumb since the thumb has a pulse of its own. The pulse should be counted for 6 seconds and the results should then be multiplied by 10. Be aware that in older individuals (over 60) or those who may be taking certain medications such as Digitalis, excessive compression of the carotid artery should be avoided since fainting can occur.

Your maximum heart rate can be determined by taking the number 220 and subtracting your age. Thus your maximal heart rate decreases one beat per minute, each year after the age of 20 - 25 years. Bear in mind that the estimate may not be accurate because the maximal heart rate varies by about 10% (i.e. the average maximum heart rate for a 40 year old person is 180 bpm, that MHR may vary from 160 - 200 bpm.). Obviously, the best way to assess maximal heart rate is by doing a stress test. After the age of 60 - 65, particularly in women, the formula becomes highly unreliable. Another method to determine the training heart rate is to take a fixed percentage of the estimated or determined maximum heart rate. This is known as the Standard Target Heart Rate. It has been shown that 60-80% of the intensity on the Borg Scale of Perceived Exertion corresponds to 60- 80% of the heart rate reserve and 70-85% of the maximal heart rate. Any irregularities should be discussed with a physician, as should related symptoms such as fatigue, fainting, dizziness, nausea, and excessive sweating. Remember that the heart rate values for women are slightly higher than those of men, whereas the ability to achieve a similar level of intensity is lower for females.

Exercise heart rate is a useful and convenient way to control intensity. For example, overtime a heart rate at a given intensity usually drops as aerobic conditioning improves. As a result, the power output should then be raised to reach the desired heart rate and intensity. Keep in mind that with increasing altitude or temperature, the heart rate will increase at any given level of exercise. Using the same training or target heart rate range as a guide, a person will be able to do less exercise at the same relative stress. Similarly, if you stop training due to such factors as injury, lack of interest or job pressures, a lower power output, or intensity, is required to exercise at the same heart rate when exercise is resumed. Remember to check your heart rate periodically during your exercise program for 6 seconds and then multiply by 10. This allows minimal time for the heart rate to recover and thus prevents a decrease in the aerobic affect. Counting for longer periods of time may be more accurate but will allow the heart rate to drop and decreases the aerobic affect. In time it may not be necessary to check your heart rate as often during your cardiovascular activity simply because you will develop a sense of the level of exertion that corresponds with your training heart rate range. (The Borg Scale of perceived exertion). Borg developed a 15 point scale with 12 and 13 being considered as somewhat hard and 16 as hard. This corresponds to 60% and 85% of the heart rate reserve, respectively.

During the warm-up and cool-down periods lasting approximately 5 - 15 minutes, the intensity should be 30 - 50% of the heart rate reserve. For sedentary individuals with low fitness levels, improvements have been obtained with intensities of 50 - 60%. For individuals over 65 years of age, 50% intensity is the threshold for most individuals and is a good level of intensity during the first weeks of increasing that individuals activity.

If there are no problems, the average intensity during the actual training program can begin at 60 - 75% and then, depending on the goal of the individual, intensity level can be increased to 70 - 85%. At intensity levels greater than 90% of the heart rate reserve, the anaerobic systems provides significant amounts of the energy, resulting in fatigue and lactic acid accumulation which tends to reduce exercise duration to less than 15 - 20 minutes. For the average individual, the optimal intensity is about 60 - 80%. Regular participation in such programs have been shown to reduce the risk of developing coronary heart disease.

The common denominator of cardiovascular function during exercises is to deliver oxygen and other nutrients to the muscles. For this purpose, the muscles blood flow increases dramatically during exercise. This is evident when you look at the maximum cardiac output of a Marathon runner. This increase in cardiac output results mainly from the fact that the chambers of the heart of marathon runners will enlarge by about 40%, and, along with the enlargement of the chambers, the mass of the heart will also increase by approximately 40% or more. Thus, it is not only skeletal muscle that will hypertrophy during athletic training, but also cardiac muscle. However, even though the heart of a marathon runner is significantly larger than that of a normal individual, the resting cardiac output is almost identical. This normal cardiac output is the result of a larger Stroke Volume and a reduced resting heart rate. Thus the heart-pumping effectiveness of each beat is 40% to 50% greater in the highly trained individual. Another physiological effect that we see during training, is an increase in the Ejection Fraction. The ejection fraction is generally expressed as a percentage. This reveals how much blood is actually ejected during the contraction of the left ventricle. This can be calculated by dividing stroke volume by the end diastolic volume of the left ventricle, and then multiplying by 100. (SV/ EDV) x 100. The ejection fraction averages about 60% at rest. In the more sedentary individual this can be as low as 50% and can increase up to as much as 70% in those highly trained athletes. These effects can be monitored and gauged by calculating the resting and training heart rates. Thus improvements can be measured and training routines can be altered for maximum efficiency of the training effects.

In summary, heart rate training offers a very direct, hands on method for the average individual to monitor performance and progress.

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