Heart rate as an indicator of the intensity of physical activity in human adolescents

Abstract

The aims of this study were, in a group of adolescents, firstly to identify the absolute heart rates (HR) and the percentages of maximal heart rates (HRmax) corresponding to 40%, 60% and 80% of peak oxygen uptake (PVO2), secondly to identify absolute and relative (%PVO2) oxygen uptakes (VO2) corresponding to HR of 120, 140 and 160 beats.min-1, and thirdly to examine a possible effect of fatness and fitness on the relationship between HR and VO2. The subjects were 127 (60 boys, 67 girls) adolescents with a mean age of 14.8 (SD 0.3) years. The HR and VO2 were measured by means of an incremental exercise test to exhaustion. Linear regressions were performed for the HR-VO2 and VO2-HR relationships using absolute and relative (%HRmax, %PVO2) data for each individual. From these regressions, target HR and VO2 were computed. Average target HR corresponding to 40%, 60% and 80% of PVO2 were: 119 (SD 9), 145 (SD 9), 171 (SD 8), and 120 (SD 10), 146 (SD 8), 172 (SD 8) beats.min-1 for boys and girls, respectively. Average VO2 corresponding to HR of 120, 140 and 160 beats.min-1 were: 22 (SD 5), 30 (SD 5), 38 (SD 6) and 18 (SD 4), 24 (SD 4), 31 (SD 4) mlO2.kg-1.min-1 for boys and girls, respectively. An analysis of covariance showed a significant fitness effect (P < 0.001) for predicted VO2 at all HR studied. The results suggest that the use of absolute HR to define exercise intensity levels when assessing young people's physical activity using HR monitoring detracts from the validity of the interpretation of the data.

Heart rate as an indicator for exercise prescription for normal, overweight, and obese adolescents

“…To our knowledge there is no data for adolescents. Even though the values presented in this study are not in accordance with previous studies (Ekelund et al, 2001;Hui & Chan, 2006), a similar linear relationship between the HR and VO 2 during CPET was observed, approving the use of HR as a valid parameter to estimate intensity in adolescents' physical activity. The differences between the studies can be explained by the characteristics of the sample (e.g.…”

“…Using the data collected in this study, it is possible to identify more precisely, and at a low cost, benefits for adolescents, considering the relationship between the HRres and the length of the aerobic activity (≥ 30 minutes per session, above 50%HRres) suggested in exercise programs (Epstein et al, 2001), and the importance of using percentages (Ekelund et al, 2001). In addition, the sample size and the techniques used in this study ensure the importance of the measure of the HRres.…”

“…This supports the need to understand the most suitable level of exercise intensity for adolescents. It is important to mention that the studies previously referred to are based on normal weight adolescents, since studies with overweight adolescents are scarce (Ekelund et al, 2001;Hui & Chan, 2006).…”

“…In fact, the relationship between VO 2 and HR during rest and exercise is well documented for adults (Cunha, Midgley, Monteiro, & Farinatti, 2010;Swain & Franklin, 2002;Swain & Leutholtz, 1997;Swain, Leutholtz, King, Haas, & Branch, 1998), and extensively used for exercise prescription (ACSM, 2013). Nonetheless, there is limited research and evidence regarding the relationship between VO 2 and HR in children and adolescents (Ekelund et al, 2001;Hui & Chan, 2006). Children and…”

Efetividade de programas de intervenção escolar para reduzir fatores de risco à saúde em adolescentes: uma revisão sistemática

“…Despite being correlated with cardiometabolic risk factors in adolescents 28,29 and easy to be used in the field with a high number of individuals, as in the school environment, these methods may have some limitations related to the lack of accuracy, especially in individuals with higher body fat 30 . Among the interventions protocols applied, three studies involved controlled exercise, using heart rate as a parameter for the monitoring physical exercise intensity 20,22,23 , and this variable is considered valid as an indicator of physical activity intensity in adolescents 31 . Most of them added education programs 20,23,24 to physical activity intervention nutrition and only one study used nutritional intervention and also demonstrated positive changes in body proportions and effectiveness in reducing BMI 21 , as previously observed in a systematic review 32 , where most of the studies showed a decrease in the prevalence of overweight and obesity among participants.…”