نوع مقاله : مقاله پژوهشی
نویسندگان
گروه فیزیولوژی ورزشی، دانشکده علوم ورزشی، دانشگاه بوعلی سینا، همدان، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Purpose: Measuring or estimating maximal heart rate (HRmax) as a physiological indicator is of great importance in adjusting the intensity of exercise training and rehabilitation programs. However, due to the implementation problems of the standard HRmax measurement, sports sciences experts recommend HRmax estimation equations. Most of these linear/nonlinear regression prediction equations are designed using samples of adult populations (20 to 90 years old), which seems to limit the application of such estimation equations to children’s and adolescents’ populations in different geographical regions due to the intervening role of the biological maturation process. Therefore, the purpose of this research was to design a native equation for estimating the HRmax for healthy Iranian children and adolescent boys.
Material and Methods: In the present study, the HRmax was measured in a modified Bruce's test on a treadmill equipped with a respiratory gas analysis device in 349 healthy boys aged 8 to 17 years in Hamedan city. Moreover, for all subjects, anthropometric and physiological variables were measured in resting conditions. Pearson's correlation was used in order to investigate the relationship between independent variables and HRmax. Stepwise regression was used to design the native equation for HRmax estimation. The indexes of coefficient of determination (R2), standard error of estimate (SEE), percentage of standard error of estimate (SEE%) and normal distribution of errors were used to evaluate the efficiency of the native model.
Results: The average ergometric HRmax of the subjects was 202.44±6.12 beats/min. There was a weak and significant correlation between HRmax and the independent variables including age, height and weight (R=-0.131-0.198, p<0.05). The HRmax of children’s and adolescents’ boys could be estimated (p=0.0002) according to the native equation "maximal heart rate (bpm) = 208.015 - 0.452 × age (years)". However, the indicators of the native equation did not have high power, so that the coefficient of determination of the equation was equal to (R2=0.04) and the standard error index was (SEE=6.14 bpm), which was equivalent to 3% of the average measured HRmax.
Conclusions: Considering the low power of the statistical indicators in the native equation of the present study, the use of the number 202 as the upper limit of maximal heart rate for Iranian children and adolescents’ boys is recommended to control the intensity of training in exercise, sports and rehabilitation workouts. Evaluating the results of the present study for greater confidence and generalization to the children and adolescents would be very valuable.
کلیدواژهها [English]