Is physical activity associated with resting heart rate in boys and girls? A representative study controlled for confounders / A atividade física está associada à frequência cardíaca de repouso em meninos e meninas? Estudo representativo controlado para fatores de confusão

Abstract Objective: Investigate the relationship between different domains of physical activity and resting heart rate (RHR) in boys and girls. Method: The sample included 1011 adolescents, aged between 10 and 17 years. RHR was measured by a heart rate monitor and physical activity was assessed in total and in three different domains (school, occupational, and sports practice) by a questionnaire. Anthropometry was directly obtained for body mass index and central fat. Ethnicity, sedentary behavior, and smoking habits were self-reported and used to adjust the analysis, through hierarchical linear regression. Results: Total physical activity was associated with low RHR in boys (β = −0.52; 95% CI: −0.92, −0.12) and girls (β = −0.67; 95% CI: −1.07, −0.28). Although sporting physical activities were associated with low RHR in both boys (β = −0.58; 95% CI: −1.05, −0.11) and girls (β = −0.87; 95% CI: −1.34, −0.39), occupational physical activity was related to low RHR only in boys (β = −1.56; 95% CI: −2.99, −0.14). Conclusion: The practice of physical activity in the sport practice domain and total physical activity were related to low RHR in both sexes, while occupational physical activities were associated with RHR only in boys.

Resumo Objetivo Investigar a relação entre diferentes domínios de atividade física e frequência cardíaca de repouso (FCRep) em meninos e meninas. Método A amostra incluiu 1.011 adolescentes, entre 10 e 17 anos. A FCRep foi medida por um monitor de frequência cardíaca e a atividade física foi avaliada no total e em três diferentes domínios (escolar, ocupacional e prática esportiva) através de um questionário. A antropometria foi obtida diretamente para o índice de massa corporal e gordura central. Etnia, comportamento sedentário e tabagismo foram autorrelatados e usados para ajustar a análise, através da regressão linear hierárquica. Resultados A atividade física total foi associada à baixa FCRep nos meninos (β = −0,52; IC95% −0,92; −0,12) e meninas (β = −0,67; IC95% −1,07; −0,28). Embora as atividades físicas esportivas estivessem associadas à baixa FCRep em ambos, meninos (β = −0,58; IC95% −1,05, −0,11) e meninas (β = −0,87; IC95% −1,34, −0,39), a atividade física ocupacional estava relacionada à baixa FCRep apenas em meninos (β = −1,56; IC95% −2,99; −0,14). Conclusão A prática de atividade física no domínio da prática esportiva e a atividade física total foram relacionadas à baixa FCRep em ambos os sexos, enquanto as atividades físicas ocupacionais foram associadas à FCRep apenas em meninos.

Is physical activity associated with resting heart rate in boys and girls? A representative study controlled for confounders.

OBJECTIVE: Investigate the relationship between different domains of physical activity and resting heart rate (RHR) in boys and girls. METHOD: The sample included 1011 adolescents, aged between 10 and 17 years. RHR was measured by a heart rate monitor and physical activity was assessed in total and in three different domains (school, occupational, and sports practice) by a questionnaire. Anthropometry was directly obtained for body mass index and central fat. Ethnicity, sedentary behavior, and smoking habits were self-reported and used to adjust the analysis, through hierarchical linear regression. RESULTS: Total physical activity was associated with low RHR in boys (ß=-0.52; 95% CI: -0.92, -0.12) and girls (ß=-0.67; 95% CI: -1.07, -0.28). Although sporting physical activities were associated with low RHR in both boys (ß=-0.58; 95% CI: -1.05, -0.11) and girls (ß=-0.87; 95% CI: -1.34, -0.39), occupational physical activity was related to low RHR only in boys (ß=-1.56; 95% CI: -2.99, -0.14). CONCLUSION: The practice of physical activity in the sport practice domain and total physical activity were related to low RHR in both sexes, while occupational physical activities were associated with RHR only in boys.

Variabilidade da frequência cardíaca e carga máxima atingida no teste de esforço físico dinâmico em homens idosos / Heart rate variability and maximum workload reached in the dynamic physical exertion test in elderly men

INTRODUÇÃO: Um dos benefícios promovidos pelo exercício físico parece ser a melhora da modulação do sistema nervoso autônomo sobre o coração. No entanto, o papel da atividade física como um fator determinante da variabilidade da frequência cardíaca (VFC) não está bem estabelecido. Desta forma, o objetivo do estudo foi verificar se há correlação entre a frequência cardíaca de repouso e a carga máxima atingida no teste de esforço físico com os índices de VFC em homens idosos. MÉTODOS: Foram estudados 18 homens idosos com idades entre 60 e 70 anos. Foram feitas as seguintes avaliações: a) teste de esforço máximo em cicloergômetro utilizando-se o protocolo de Balke para avaliação da capacidade aeróbia; b) registro da frequência cardíaca (FC) e dos intervalos R-R durante 15 minutos na condição de repouso em decúbito dorsal. Após a coleta, os dados foram analisados no domínio do tempo, calculando-se o índice RMSSD, e no domínio da frequência, calculando-se os índices de baixa frequência (BF), alta frequência (AF) e razão BF/AF. Para verificar se existe associação entre a carga máxima atingida no teste de esforço e os índices de VFC foi aplicado o teste de correlação de Pearson (p < 0,05). RESULTADOS: Características demográficas, antropométricas, fisiológicas e carga máxima atingida no teste ergométrico: idade = 63 ± 3,0 anos; IMC = 24 ± 2kg/m²; FC = 63 ± 9bpm; PAS = 123 ± 19mmHg; PAD = 83 ± 8mmHg; carga máxima = 152 ± 29 watts. Não houve correlação entre os índices de VFC com os valores de FC de repouso e carga máxima atingida no teste ergométrico (p > 0,05). CONCLUSÃO: Os índices de variabilidade da frequência cardíaca temporal e espectrais estudados não são indicadores do nível de capacidade aeróbia de homens idosos avaliados em cicloergômetro.

INTRODUCTION: One of the benefits provided by regular physical activities seems to be the improvement of cardiac autonomic nervous system modulation. However, the role of physical activity as a determinant factor of the heart rate variability (HRV) is not well-established. Therefore, the aim of this study was to verify whether there was a correlation between resting heart rate and maximum workload reached in an exercise test with HRV indices in elderly men. METHODS: A study was carried out with 18 elderly men between the ages of 60 and 70 years. The following evaluations were made: a) Maximal exercise test on a cycle ergometer using Balke treadmill protocol to evaluate the aerobic capacity; b) Heart Rate (HR) and RR Intervals (RRi) registered for 15 minutes at rest, in the supine position. After collection, data were analyzed by time domain (RMSSD index) and by the frequency domain (low (LF) and high (HF) frequency indices and LF/HF ratio). Pearson correlation test was used to verify whether there was a correlation between the maximum workload reached during the exercise test and the HRV indices (p < 0.05). RESULTS: Demographic, physiological, and anthropometric characteristics and the maximum load achieved during exercise test: Age = 63 ± 3.0 years; BMI = 24 ± 2 kg/m2; HR = 63 ± 9 bpm; SBP = 123 ± 19 mmHg; DBP = 83 ± 8 mmHg; maximum workload = 152 ± 29 watts. No correlation was found between the HRV indices with the values of the resting heart rate and the maximum workload reached in the exercise test (p > 0.05). CONCLUSION: Temporal and spectral indices of heart rate variability are not indicators of aerobic capacity of elderly men evaluated on a cycle ergometer.

Entrenamiento continuo e interválico sobre el fitness cardiovascular en mujeres sedentarias / Continuos and intervalic training on cardiovascular fitness in sedentary women

Objetivo: Evaluar si el ejercicio interválico cercano al máximo de intensidad en una población de fitness similar y del mismo sexo es más efectivo que el continuo de menor intensidad para mejorar la capacidad aerobia. Metodología: Se seleccionaron diez mujeres sanas entre 18 y 25 años, habitantes habituales de la ciudad de Bogotá (2600 msnm), quienes firmaron el consentimiento informado, y se dividieron al azar en dos grupos de cinco participantes cada uno. Fueron sometidas a dos tipos tradicionales de entrenamiento de diez semanas de duración, tres veces/semana, de una hora de duración cada día. El grupo de entrenamiento continuo (grupo 1) tenía una intensidad del 60% del VO2pico y el de entrenamiento interválico (grupo 2) trabajó cinco sesiones de diez minutos de ejercicio al 70% del VO2pico y noventa segundos de recuperación entre cada sesión. Resultados: Se pudo evidenciar que, aunque las medias de la frecuencia cardiaca (FC) de las participantes del entrenamiento interválico durante las sesiones de ejercicio siempre estuvieron por encima de las de entrenamiento continuo, esta diferencia no fue estadísticamente significativa. De igual manera, la FC basal y la de recuperación así como el VO2pico no tuvieron diferencias significativas entre los dos grupos. La media de las presiones arterial sistólica y diastólica así como la frecuencia respiratoria (FR) siempre fueron superiores en el entrenamiento interválico, estas diferencias sí fueron significativas. Conclusiones: Se pudo concluir que no hay una diferencia significativa del fitness cardiovascular entre mujeres jóvenes sedentarias luego de diez semanas de dos tipos tradicionales de entrenamiento aerobio, uno al 60% continuo y otro al 70% interválico.

The purpose of this investigation was to evaluate if the intervallic exercise near to the maximum of intensity in a similar fitness population and in women is more effective to improve aerobic capacity than the continuous one of smaller intensity. In order to do it, ten healthy women between 18 and 25 years habitual inhabitants of Bogotá city (located at 2600masl) were selected. They signed the informed consent and were divided randomly in two groups of five participants. They were undergoing to two traditional types of training of ten weeks, three times per week, one hour of duration every day. The continuous training group (Group 1) had a VO2peak intensity of 60%; for his part, the intervallic training group (Group 2) had five sessions of ten minutes of exercise at 70% of VO2peak and 90 seconds of recovery between each session. It was possible to demonstrate that, although the Cardiac Frequency (CF) average of group 2 participants during the exercise sessions were always over those of group 1, this difference was not statistically significant. In the same way, the basal CF and the recovery CF, as well as the VO2peak, did not have significant differences between both groups. The systolic and diastolic blood pressure average, as well as the Respiratory Frequency (FR) were always superior in group 2, and these differences were really significant. It was possible to conclude that there is not a significant difference in cardiovascular fitness between sedentary young women, after 10 weeks of two traditional types of aerobic training, one 60% continuous and other one 70% intervalic.