Intensity refers to the degree of vigorousness of a single session of exercise. The intensity level recommended by the american college of sports medicine (ACSM) in 1990 for the purpose of developing physical fitness was 60% to 90% of the maximal heart rate. HRmax can be measured by a physical work capacity test on a treadmill or cycle ergometer. Because most people do not have access to such tests, HRmax can be estimated by subtracting age from 220. A 20 year old person has an estimated HRmax of 200 beats per minute. This formula predicts rather than measures HRmax; therefore a measurement error of approximately plus or minus 10 beats per minute is associated with its use.
After the HRmax has been determined, the target for exercise may be calculated. The target zone for exercise provides the desirable heart rate for the development of physical fitness, For the 20 year old individual whose HRmax is 200 beats per minute.
This 20 year old person should exercise at a heart rate between 120 and 180 beats per minute, depending on objectives and level of fitness. The target for a person whose level of fitness is average is 150 to 160 beats per minute for exercise. The training effect occurs at heart rate levels below the maximum.
Another method for calculating exercise heart rate, the karvonen formula, considers fitness level and resting heart rate. The training heart rate is calculated with this formula by using a percentage of the heart rate reserve, which is the difference between the HRmax and the resting heart rate. The best way to determine the resting heart rate for this method is to count the pulse rate for 15 seconds while in the sitting position immediately after waking in the morning. You should repeat this for 4 to 5 consecutive days and average the readings for a relatively accurate representation of resting heart rate. If you cannot decide which category is the most appropriate. Your performance on these should place you in a category that reflects your physical fitness level.
Learning to take the pulse rate quickly and accurately is necessary to monitor exercise intensity by heart rate. Two of the most commonly used sites for taking the pulse rate are the radial artery at the thumb side of the wrist and the carotid artery at the side of the neck . You use the first two fingers of the preferred hand to palpate the pulse. At the wrist, the pulse is located at the base of the thumb with the hand held palm up. For the carotid pulse, you should slide your fingers downward at the angle of the jaw below the earlobe to the side of the neck. You apply only enough pressure to feel the pulse, particularly at the carotid artery. Excessive pressure at this point stimulates specialized receptors that automatically slow the heart rate, leading to an underestimation of the rate actually achieved during exercise. The wrist is the preferred site for the palpation (examination by touch or feel) of the pulse rate. You should use the carotid pulse if you cannot feel your pulse at the wrist.
You should locate and count the pulse rate immediately after exercise stops. You count the beats for 10 seconds and multiply by 6 to get beats per minute. You may start the count by assigning a zero to the first beat that is felt, or you may, as nurses do, start the count by assigning the first beat felt a value of one. Regardless of which technique you use, you should be consistent in its application. Some practice is required to locate the pulse quickly and to count it accurately.
Another method for monitoring the intensity of exercise is by rating your subjective perception of the effort. On some days, exercise seems easier than normal, and other days it may seem more difficult. The intensity level of exercise for most people should fall in the categories of 11 to 15, and this should correspond approximately to the target heart rate. In other words, if you are in the appropriate target heart rate zone, the perceived exertion will probably be between 11 and 15.
In 1995, the ACSM issued its newest guidelines for physical activity. To reiterate, the statement recommends that all adults should accumulate 30 minutes or more of moderate intensity physical activity on most if not all days of the week. This recommendation was not intended to replace the 1990 guidelines, but rather to motivate the inactive and sporadically active to become regularly active for the purpose of health enhancement. Those who are following the 1990 guidelines should continue to do so, while those who are following the new guidelines should attempt to move to a higher level.
Tags:category that reflects your physical fitness level. Intensity refers to the degree of vigorousness of a single session of exercise