Maximum pulse: how to calculate correctly
The maximum pulse (MP) is the maximum heart rate achieved during the maximum physical activity and without serious health problems. Use such calculations to determine the personal "training zone." This allows you to monitor the pulse within the permissible range, and if necessary, reduce the load in time, that is, before the disease occurs.
Since the maximum pulse is a subjective parameter, the most accurate way of measuring it in one person can be performed with the help of a cardiac stress test.
With age, MP is usually reduced, although while maintaining physical activity at a sufficient level, MP can be maintained within optimal limits. At its definition the indicator is most often used as age. In other formulas, the weight of a particular person is additionally involved. Sometimes the maximum pulse can be calculated independently, in other cases, medical care is required, as in the case of a stress test.
Video Tips for runners. How to determine the maximum heart rate
Since MP depends on the physiological characteristics of a particular person, the most accurate way of measuring it can be done using a stress test. During this study, a person undergoes a controlled physiological load (usually through a treadmill) while recording an ECG. The intensity of physical exercises increases periodically until certain changes in the cardiac function are detected on the ECG monitor, after which the testing stops. In the usual version, the test duration is from ten to twenty minutes.
Adults who begin a new set of exercises are often advised to pass this test only in the presence of medical personnel because of the possible risks associated with high heart rate.
For general familiarization, a formula is frequently used to estimate the maximum pulse of a particular person. However, these predictive formulas are often criticized because of their inaccuracy, as they generalize the average population and usually focus on the age of a person. It is well known that there is an "unfavorable relationship between maximum pulse and age" and large standard deviations with respect to predicted heartbeats [1 - Froelicher, Victor; Myers, Jonathan (2006). Exercise and the Heart (fifth ed.). Philadelphia: Elsevier. pp. ix, 108-12.]. Therefore, it is worthwhile to know about the limitations of the evaluation formulas, which will be discussed below.
There are various formulas that give different values for the maximum heart rate according to the age of the subject.
Formula Bjarne Nes
Based on the measurements of 3,320 healthy men and women aged 19 to 89 years, including the potentially changing effect of sex, body composition and physical activity, researcher Nes et al. Presented the following formula:
MP = 211 - (0.64 × age)
It was found that this relationship persists, regardless of sex, physical activity status, maximum oxygen consumption, smoking or body mass index. However, the standard error of the estimate is 10.8 bpm. should be considered when applying the formula in a clinical setting, so the researchers concluded that the actual use of the MP test may be preferable when possible.
Formula Tanaka, Monahan and Seals
Presented in the following form:
MP = 208 - (0.7 × age)
The authors' analysis is based on 351 previous studies involving 492 groups with a total of 18,712 patients). Also, laboratory studies were conducted involving 514 clinically healthy subjects. As a result, they concluded that with the use of this equation, the MP was very strongly correlated with age (r = -0.90). The regression equation obtained in a laboratory study (age 209 - 0.7 x) is almost identical to the meta-study equation.
The results showed that MP does not depend on sex and does not depend on wide differences in the levels of habitual physical activity. Also in this study, it was determined that the standard deviation is approximately 10 bpm. at any age, which indicates the accuracy of the MP calculation with the help of the reduced formula ± 20 bpm.
In 2007, researchers from the University of Oakland analyzed the maximum pulse in 132 people over 25 years of age, and obtained a linear equation very similar to the Tanaka formula, where MP = 206.9 - (0.67 × age) and the nonlinear equation MP = 191.5 - (0.007 × age2). The linear equation had a confidence interval of ± 5-8 bpm, and the nonlinear equation had a narrower range of ± 2-5 bpm. A third nonlinear equation was also obtained: MP = 163 + (1.16 × age) - (0.018 × age2).
Formula Haskell and Fox
Estimation of MP using the Haskell and Fox formula is most often performed. Despite the studies of Tanaka, Monahan and Seals, the most widely cited formula for determining MP (which does not refer to any standard deviation) is:
MP = 220 - age
The formula was developed in 1970 by Dr. William Haskell and Dr. Samuel Fox [3 - Kolata, Gina (2001-04-24).'Maximum' Heart Rate Theory Is Challenged. New York Times.]. A study of the history of this formula shows that it was not developed from original research, but was derived from observations based on data from approximately 11 references consisting of published studies or unpublished scientific collections. It is widely used thanks to the use of Polar Electro in the work of heart rate monitors.
Although the formula is the most common (it is easy to remember and simply calculate the MP), it is not considered authoritative among health and fitness professionals, so it can not be a good predictor of MP. Despite the widespread use of this formula, studies spanning two decades show errors associated with it, approximately 7-11 beats / min.Consequently, the estimate, calculated by MP = 220 - age, has neither accuracy nor scientific merit for use in the physiology of exercises and related fields of medicine.
Limitations of Estimating Formulas
The values of the maximum heart rate vary significantly among different people. It is reported that even within the framework of one elite sports team, such as Olympic rowers at the age of 20, the maximum heart rate ranges from 160 to 220. Such a variation will be equal to the difference in the age of 60 or 90 years in linear equations and, apparently, on extreme fluctuations of these average indicators.
Figures are usually considered average and largely depend on individual physiology and physical form. For example, endurance rates for runners will tend to be lower due to the increased size of the heart needed to perform the exercises, while the sprinter rates will be higher due to improved response time and short duration. Although each of them can be calculated MP 180 (= 220 - age), so these two athletes can differ in actual MP by 20 beats / min. (e.g. 170-190).
In addition, it should be noted that people of the same age, with the same training, engaged in the same sport in the same team can have the actual MP 160-220: The range is extremely wide, therefore, as an MP indicator, it is probably the least important variable when comparison of athletes.
Video What Should Pulse Be in Training Time?