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Objective To explore the formula of predicting the maximum heart rate (HRmax) of college students in China from age,and examine its validity.Methods One hundred and one students (aged 20.9 ± 1.52 years) were recruited to undergo the VO2max test,and the HRmax was acquired after they finished the graded exercise test (GXT).The predicted value was also obtained according to the formulae of the age-predicted Hrmax:205.8-0.685 × age,206.9-0.67 × age and 210-0.66 × age.Results According to the paired t-test and one-way analysis of the variance,it was found that significant differences were observed between the measured HRmax and all the predicted values except the one got according to the formula of 210-0.66×Age.Through the method of Bland-Aitman plot,the predicted value of 210-0.66×age was more consistent with the measured value.Conclusion The 210-0.66×age equation owns the acceptable level of prediction error,and is the most suitable one of the four equations to predict the HRmax of college students in China.
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Abstract: Introduction and objective: Maximum heart rate (MHR) is essential to establish the effort, intensity and strategies for physical activity. For this, there are more than 40 formulas; among the best known are 220-Age and Tanaka. The objective of this research is to determine the validity and effectiveness of the equations for MHR. Material and methods: Observational, descriptive and transversal study with a sample of 300 participants (181 women and 119 men) with a mean age of 26 ± 10 years. For the development of this research, we used anthropometry, vital signs, Borg scale and questionnaire for cardiovascular risk factors and a stress test and compare the data with 25 equations of MHR. Results: Maximum heart rate by stress test of the 300 participants was 179.6 ± 15 beats per minute; regarding 25 equations, was observed an overestimation up to 19 beats per minute. Only the formulas of Morris and Graettinger scored less than 4 beats per minute apart to stress test. Conclusions: No one is recommended equations evaluated for their significant difference in the stress test; especially 220-edad, Hossack y Bruce, Cooper and Lester whose difference mean were above 14 beats per minute (p = 0.000). The equation of Morris (p = 0.380) no were found significant differences and were the most successful to estimate the MHR for a minimum difference compared to a stress test.
Resumen: Introducción y objetivo: La frecuencia cardiaca máxima (FCM) es un parámetro esencial para esTablecer el esfuerzo, intensidad y estrategias de la actividad física. Para ello, existen más de 40 fórmulas; entre las más conocidas son 220-edad y Tanaka. El objetivo de la presente investigación es determinar la validez y efectividad de las ecuaciones para la FCM. Material y métodos: Estudio observacional, descriptivo y transversal con 300 participantes (181 mujeres y 119 hombres), de edad promedio de 26 ± 10 años. Para el desarrollo de esta investigación, se obtuvo antropometría, signos vitales, escala de Borg, cuestionario para factores de riesgo cardiovascular y realización de prueba de esfuerzo para comparar datos con 25 ecuaciones de FCM. Resultados: La FCM por prueba de esfuerzo en los 300 participantes fue de 179.6 ± 15 latidos por minuto; en cuanto a las 25 ecuaciones, se observó una sobreestimación hasta en 19 latidos por minuto y sólo las fórmulas de Morris y Graettinger obtuvieron menos de cuatro latidos por minuto de diferencia a la prueba de esfuerzo. Conclusiones: No se recomienda alguna de las ecuaciones evaluadas por su diferencia significativa respecto a la prueba de esfuerzo; especialmente 220-edad, Hossack y Bruce, Cooper y Lester cuya diferencia de media estuvo por encima de 14 latidos por minutos (p = 0.000). Para la ecuación de Morris (p = 0.380) no se encontraron diferencias significativas y fue la más acertada para estimar la FCM comparada con una prueba de esfuerzo.
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Objetivo. Comparar la frecuencia cardíaca máxima (FCmax) alcanzada con la esperada según la fórmula clásica (220 menos edad) y la propuesta por Tanaka [208,75 - (0,73 x edad)] en diferentes poblaciones para determinar cuál es la ecuación más exacta, en vista de que este parámetro es muy utilizado para la evaluación de la reserva cronotrópica y coronaria. Material y método. Estudio descriptivo, observacional y transversal con 910 pacientes que realizaron prueba ergométrica graduada en el Instituto Médico Río Cuarto (Córdoba, Argentina) durante 2012-2013. Se utilizó el protocolo de Astrand. Se evaluó la FCmax alcanzada y esperada de cada paciente mediante la fórmula clásica y la de Tanaka. Se compararon dichos resultados según el género, rango etario, índice de masa corporal (IMC), presencia de factores de riesgo (hipertensión arterial, diabetes mellitus, dislipidemia, enfermedad coronaria previa y/o tabaquismo) y consumo de beta bloqueantes. Para el análisis estadístico se utilizó Microsoft Excel y SPSS, y la probabilidad estadística mediante el índice de Pearson con un valor <0,01. Resultados. Se analizaron 910 pacientes, 554 (61%) de género masculino y 356 (39%) femenino, la edad promedio fue de 47±16 años, el IMC fue de 27±5. El 48% de la población presentó uno o más factores de riesgo y el 15% estaba bajo tratamiento con beta bloqueantes. Al analizar la FCmax alcanzada por el paciente y compararla con la esperada según ambas fórmulas, se halló una sobreestimación por parte de las mismas, resultando más precisa en los menores de 40 años, la de Tanaka, y en los mayores de 40 años, la fórmula clásica. En los pacientes con IMC >25 y en los tratados con beta bloqueantes, se evidenció una sobreestimación de la FCmax esperada con ambas fórmulas. Conclusiones. La fórmula de Tanaka fue más precisa en los pacientes menores de 40 años sin diferencias respecto al género, por lo que sugerimos utilizar esta ecuación para dicha población y reservar la clásica para los mayores de 40 años. Esta relación se mantuvo en las subpoblaciones según presencia o no de factores de riesgo e IMC. Estos hallazgos tendrían el efecto de subestimar el verdadero nivel de estrés físico impuesto durante la prueba de esfuerzo y la intensidad adecuada de los programas de ejercicios prescriptos. La población que utilizaba beta bloqueantes presentó una sobreestimación con ambas fórmulas, siendo más acentuada cuanto más joven era el paciente.
Objective. To compare the maximum heart rate (HRmax) reached with the expected according to the classical formula (220 minus age) and that proposed by Tanaka [208,75 - (0,73 x age)] in different populations to determine which is the most accurate equation, given that this parameter is used to evaluate the chronotropic and coronary reserve. Material and method. Descriptive, observational and cross-sectional study with 910 patients who underwent exercise stress test graduated at the Medical Institute Rio Cuarto (Cordoba, Argentine) during 2012-2013. Åstrand protocol was used. HRmax achieved and expected of each patient by the classic formula and Tanaka's formula were evaluated. These results were compared by gender, age range, body mass index (BMI), presence of risk factors (hypertension, diabetes mellitus, dyslipidemia, previous coronary disease and/or smoking) and use of beta blockers. Microsoft Excel for statistical analysis and SPSS was used, and the statistical probability by Pearson index with a value <0.01. Results. The 910 patients, 554 (61%) of male and 356 (39%) female, mean age was 47±16 years, BMI was 27±5 were analyzed. The 48% of the population had one or more risk factors and 15% were treated with beta blockers. When analyzing the HRmax reached by the patient and compared with the expected according to both formulas, an overestimation was found by them, resulting in more accurate Tanaka's formula in the under 40 years and the classic formula those over 40 years. In patients with BMI >25 and in those treated with beta blockers, an overestimation of HRmax expected with both formulas was evidenced. Conclusions. Tanaka's formula was more accurate in patients younger than 40 years without sex differences, so we suggest using this equation for this population and reserve the classic formula for over 40 years. This relationship remained in subpopulations according to presence or absence of risk factors and BMI. These findings would have the effect of underestimating the true level of physical stress imposed during the stress test and the right intensity of exercise prescribed programs. The population using beta blockers showed an overestimation with both formulas, being more pronounced the younger was the patient.
Objetivo. Comparar a frequência cardíaca máxima (FCmax) alcançada com a esperada de acordo com a fórmula clássica (220 menos a idade) e o proposto por Tanaka [208,75 - (0,73 x idade)] em populações diferentes para determinar qual é a equação mais precisa, uma vez que este parâmetro é utilizado para avaliar da reserva cronotrópica e coronária. Material e método. Estudo descritivo, observacional e transversal, com 910 pacientes que foram submetidos a teste progressivo de esforço no Instituto de Medicina do Rio Cuarto (Córdoba, Argentina) durante 2012-2013. Foi utilizado o protocolo de Åstrand. Foi avaliada a FCmax alcançada e esperada de cada paciente pela fórmula clássica e fórmula de Tanaka. Estes resultados foram comparados por sexo, faixa etária, índice de massa corporal (IMC), a presença de fatores de risco (hipertensão arterial, diabetes mellitus, dislipidemia, doença coronariana prévia e/ou tabagismo) e consumo de beta-bloqueadores. Para análise estatística foi utilizada Microsoft Excel e SPSS, e a probabilidade estatística pelo índice de Pearson, com um valor <0,01. Resultados. Foram analisados 910 pacientes, 554 (61%) do sexo masculino e 356 (39%) do sexo feminino, com idade média de 47±16 anos, o IMC foi de 27±5. O 48% da população apresentaram um ou mais fatores de risco e 15% foram tratados com betabloqueadores. Ao analisar a FCmax alcançada pelo paciente e comparada com a esperada de acordo com ambas as fórmulas, uma superestimação foi encontrada por eles, resultando mais precisa a fórmula Tanaka em menores de 40 anos e a fórmula clássica em pessoas com mais de 40 anos. Em pacientes com IMC >25 e naqueles tratados com betabloqueadores, foi demonstrada uma superestimação da FCmax esperada com ambas as fórmulas. Conclusões. A fórmula de Tanaka foi mais precisa em pacientes com menos de 40 anos sem diferenças entre os sexos, por isso sugerimos usar esta equação para essa população e fórmula clássica para os maiores de 40 anos. Esta relação manteve-se em subpopulações de acordo com a presença ou a ausência de fatores de risco e IMC. Estes achados teriam o efeito de subestimar o verdadeiro nível de estresse físico imposta durante o teste de esforço e a intensidade certa de programas de exercício prescrito. A população utilizando betabloqueadores demonstrou uma superestimação com as duas fórmulas, sendo mais pronunciada quanto mais jovem foi o paciente.
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BACKGROUND: Few studies have examined ambulatory cardiovascular physiological parameters of taxi drivers while driving in relation to their occupational hazards. This study aims to investigate and quantify the impact of worksite physical hazards as a whole on ambulatory heart rate of professional taxi drivers while driving without their typical worksite psychosocial stressors. METHODS: Ambulatory heart rate (HRdriving) of 13 non-smoking male taxi drivers (24 to 67 years old) while driving was continuously assessed on their 6-hour experimental on-road driving in Los Angeles. Percent maximum HR range (PMHRdriving) of the drivers while driving was estimated based on the individual HRdriving values and US adult population resting HR (HRrest) reference data. For analyses, the HRdriving and PMHRdriving data were split and averaged into 5-min segments. Five physical hazards inside taxi cabs were also monitored while driving. Work stress and work hours on typical work days were self-reported. RESULTS: The means of the ambulatory 5-min HRdriving and PMHRdriving values of the 13 drivers were 80.5 bpm (11.2 bpm higher than their mean HRrest) and 10.7 % (range, 5.7 to 19.9 %), respectively. The means were lower than the upper limits of ambulatory HR and PMHR for a sustainable 8-hour work (35 bpm above HRrest and 30 % PMHR), although 15–27 % of the 5-min HRdriving and PMHRdriving values of one driver were higher than the limits. The levels of the five physical hazards among the drivers were modest: temperature (26.4 ± 3.0 °C), relative humidity (40.7 ± 10.4 %), PM2.5 (21.5 ± 7.9 μg/m3), CO2 (1,267.1 ± 580.0 ppm) and noise (69.7 ± 3.0 dBA). The drivers worked, on average, 72 h per week and more than half of them reported that their job were often stressful. CONCLUSIONS: The impact of physical worksite hazards alone on ambulatory HR of professional taxi drivers in Los Angeles generally appeared to be minor. Future ambulatory heart rate studies including both physical and psychosocial hazards of professional taxi drivers are warranted.