Marcos Roberto Queiroga

Validation of the Brzycki equation for the estimation of 1-RM in the bench press

The aim of the present study was to analyze the validation of the equation proposed by Brzycki for the prediction of a maximum repetition (1-RM) in the bench press. Fifty sedentary or moderately active male subjects (22.2 ± 3.5 years; 64.7 ± 8.6 kg), were initially submitted to six test sessions of 1-RM in the bench press, with 48 hours of interval between each session, in order to determine the maximum workload. A protocol of force resistance was then performed for the determination of 7-10-RM. The used criteria for the validation included: t-Student test for dependent samples, for comparison among the mean values obtained by the predictive equation and by the 1-RM test; Pearson correlation coefficient for analysis of the association degree among the measurements; standard error of estimate (SEE) for evaluation of the mean deviation degree of the individual data along the produced line; total error (TE) for the verification of the mean deviation of the individual values of the identity line; constant error (CE) for analysis of the difference among the mean values obtained in the 1-RM test and predicted by the proposed equation. None statistically significant difference was verified among the values produced by the 1-RM test and the Brzycki equation (P > 0.05). Both the SEE and the TE were relatively low (2.42 kg or 3.4% and 1.55 kg or 2.2%, respectively), as well as the CE found (0.22 kg or 0.3%). Moreover, the correlation coefficient value found was extremely high (r = 0.99; P < 0.05), thus showing a strong association between the values found by the 1-RM test and the Brzycki equation. Therefore, the equation analyzed by this study satisfied the validation criteria established by the literature. The results suggest that the Brzycki equation seems to be a fairly attractive alternative for the estimation of 1-RM values in the bench press from the performance of submaximal tests of 7-10-RM, in sedentary or moderately active male adults.The aim of the present study was to analyze the validation of the equation proposed by Brzycki for the prediction of a maximum repetition (1-RM) in the bench press. Fifty sedentary or moderately active male subjects (22.2 ± 3.5 years; 64.7 ± 8.6 kg), were initially submitted to six test sessions of 1-RM in the bench press, with 48 hours of interval between each session, in order to determine the maximum workload. A protocol of force resistance was then performed for the determination of 7-10-RM. The used criteria for the validation included: t-Student test for dependent samples, for comparison among the mean values obtained by the predictive equation and by the 1-RM test; Pearson correlation coefficient for analysis of the association degree among the measurements; standard error of estimate (SEE) for evaluation of the mean deviation degree of the individual data along the produced line; total error (TE) for the verification of the mean deviation of the individual values of the identity line; constant error (CE) for analysis of the difference among the mean values obtained in the 1-RM test and predicted by the proposed equation. None statistically significant difference was verified among the values produced by the 1-RM test and the Brzycki equation (P > 0.05). Both the SEE and the TE were relatively low (2.42 kg or 3.4% and 1.55 kg or 2.2%, respectively), as well as the CE found (0.22 kg or 0.3%). Moreover, the correlation coefficient value found was extremely high (r = 0.99; P < 0.05), thus showing a strong association between the values found by the 1-RM test and the Brzycki equation. Therefore, the equation analyzed by this study satisfied the validation criteria established by the literature. The results suggest that the Brzycki equation seems to be a fairly attractive alternative for the estimation of 1-RM values in the bench press from the performance of submaximal tests of 7-10-RM, in sedentary or moderately active male adults.

Desempenho em testes de força estática: comparação entre trabalhadores hipertensos e normotensos

OBJECTIVE: The aim of the study was to compare static muscular strength test performance between hypertensive and normotensive workers, considering the hypothesis that hypertensive individuals have lower strength than normotensive individuals. METHODS: The participants consisted of 354 workers (246 men and 108 women) who underwent height, body mass, waist circumference, systolic and diastolic blood pressure (BP) measurements, as well as right and left handgrip, and scapular and lumbar strength tests. Assessments were performed during three days in all three shifts, with workers from a candy and sweets factory located in Rio Claro, SP, Brazil. BP measurements were performed with a 10-minute interval, with the subject in the sitting position. Before the strength tests were performed, the workers were familiarized with the equipment; the highest value was recorded after two attempts at each test. RESULTS: The results showed significant differences between hypertensive and normotensive individuals for age, body mass, body mass index, and waist circumference greater for hypertensive individuals. Regarding static muscle strength tests performance, the hypertensive individuals did not differ significantly from normotensive individuals; however, this difference was observed when groups divided by body mass index (BMI) were compared. The obesity group had strength values above those of the normal weight/overweight group among normotensive individuals, but this was not observed among the hypertensive individuals. As for the intragender comparison, there were no significant differences for the strength tests. CONCLUSION: Normotensive and hypertensive workers showed no significant differences in the performance of static muscular strength tests; however, body mass and gender seem to affect the association between muscle strength and blood pressure.OBJECTIVE The aim of the study was to compare static muscular strength test performance between hypertensive and normotensive workers, considering the hypothesis that hypertensive individuals have lower strength than normotensive individuals. METHODS The participants consisted of 354 workers (246 men and 108 women) who underwent height, body mass, waist circumference, systolic and diastolic blood pressure (BP) measurements, as well as right and left handgrip, and scapular and lumbar strength tests. Assessments were performed during three days in all three shifts, with workers from a candy and sweets factory located in Rio Claro, SP, Brazil. BP measurements were performed with a 10-minute interval, with the subject in the sitting position. Before the strength tests were performed, the workers were familiarized with the equipment; the highest value was recorded after two attempts at each test. RESULTS The results showed significant differences between hypertensive and normotensive individuals for age, body mass, body mass index, and waist circumference greater for hypertensive individuals. Regarding static muscle strength tests performance, the hypertensive individuals did not differ significantly from normotensive individuals; however, this difference was observed when groups divided by body mass index (BMI) were compared. The obesity group had strength values above those of the normal weight/overweight group among normotensive individuals, but this was not observed among the hypertensive individuals. As for the intragender comparison, there were no significant differences for the strength tests. CONCLUSION Normotensive and hypertensive workers showed no significant differences in the performance of static muscular strength tests; however, body mass and gender seem to affect the association between muscle strength and blood pressure.

Validação da equação de Brzycki para a estimativa de 1-RM no exercício supino em banco horizontal

The aim of the present study was to analyze the validation of the equation proposed by Brzycki for the prediction of a maximum repetition (1-RM) in the bench press. Fifty sedentary or moderately active male subjects (22.2 ± 3.5 years; 64.7 ± 8.6 kg), were initially submitted to six test sessions of 1-RM in the bench press, with 48 hours of interval between each session, in order to determine the maximum workload. A protocol of force resistance was then performed for the determination of 7-10-RM. The used criteria for the validation included: t-Student test for dependent samples, for comparison among the mean values obtained by the predictive equation and by the 1-RM test; Pearson correlation coefficient for analysis of the association degree among the measurements; standard error of estimate (SEE) for evaluation of the mean deviation degree of the individual data along the produced line; total error (TE) for the verification of the mean deviation of the individual values of the identity line; constant error (CE) for analysis of the difference among the mean values obtained in the 1-RM test and predicted by the proposed equation. None statistically significant difference was verified among the values produced by the 1-RM test and the Brzycki equation (P > 0.05). Both the SEE and the TE were relatively low (2.42 kg or 3.4% and 1.55 kg or 2.2%, respectively), as well as the CE found (0.22 kg or 0.3%). Moreover, the correlation coefficient value found was extremely high (r = 0.99; P < 0.05), thus showing a strong association between the values found by the 1-RM test and the Brzycki equation. Therefore, the equation analyzed by this study satisfied the validation criteria established by the literature. The results suggest that the Brzycki equation seems to be a fairly attractive alternative for the estimation of 1-RM values in the bench press from the performance of submaximal tests of 7-10-RM, in sedentary or moderately active male adults.The aim of the present study was to analyze the validation of the equation proposed by Brzycki for the prediction of a maximum repetition (1-RM) in the bench press. Fifty sedentary or moderately active male subjects (22.2 ± 3.5 years; 64.7 ± 8.6 kg), were initially submitted to six test sessions of 1-RM in the bench press, with 48 hours of interval between each session, in order to determine the maximum workload. A protocol of force resistance was then performed for the determination of 7-10-RM. The used criteria for the validation included: t-Student test for dependent samples, for comparison among the mean values obtained by the predictive equation and by the 1-RM test; Pearson correlation coefficient for analysis of the association degree among the measurements; standard error of estimate (SEE) for evaluation of the mean deviation degree of the individual data along the produced line; total error (TE) for the verification of the mean deviation of the individual values of the identity line; constant error (CE) for analysis of the difference among the mean values obtained in the 1-RM test and predicted by the proposed equation. None statistically significant difference was verified among the values produced by the 1-RM test and the Brzycki equation (P > 0.05). Both the SEE and the TE were relatively low (2.42 kg or 3.4% and 1.55 kg or 2.2%, respectively), as well as the CE found (0.22 kg or 0.3%). Moreover, the correlation coefficient value found was extremely high (r = 0.99; P < 0.05), thus showing a strong association between the values found by the 1-RM test and the Brzycki equation. Therefore, the equation analyzed by this study satisfied the validation criteria established by the literature. The results suggest that the Brzycki equation seems to be a fairly attractive alternative for the estimation of 1-RM values in the bench press from the performance of submaximal tests of 7-10-RM, in sedentary or moderately active male adults.

Nutritional status of children and adolescents based on body mass index: agreement between World Health Organization and International Obesity Task Force.

Objective: To investigate the agreement between two international criteria for classification of children and adolescents nutritional status. Methods: The study included 778 girls and 863 boys aged from six to 13 years old. Body mass and height were measured and used to calculate the body mass index. Nutritional status was classified according to the cut-off points defined by the World Health Organization and the International Obesity Task Force. The agreement was evaluated using Kappa statistic and weighted Kappa. Results: In order to classify the nutritional status, the agreement between the criteria was higher for the boys (Kappa 0.77) compared to girls (Kappa 0.61). The weighted Kappa was also higher for boys (0.85) in comparison to girls (0.77). Kappa index varied according to age. When the nutritional status was classified in only two categories - appropriate (thinness + accentuated thinness + eutrophy) and overweight (overweight + obesity + severe obesity) -, the Kappa index presented higher values than those related to the classification in six categories. Conclusions: A substantial agreement was observed between the criteria, being higher in males and varying according to the age.Objective: To investigate the agreement between two international criteria for classification of children and ado - lescents nutritional status. Methods: ...

Development of the Color Scale of Perceived Exertion: Preliminary Validation

This study developed a Color Scale of Perceived Exertion (RPE-color scale) and assessed its concurrent and construct validity in adult women. One hundred participants (18–77 years), who were habitual exercisers, associated colors with verbal anchors of the Borg RPE scale (RPE-Borg scale) for RPE-color scale development. For RPE-color scale validation, 12 Young (M = 21.7 yr., SD = 1.5) and 10 Older (M = 60.3 yr., SD = 3.5) adult women performed a maximal graded exercise test on a treadmill and reported perceived exertion in both RPE-color and RPE-Borg scales. In the Young group, the RPE-color scale was significantly associated with heart rate and oxygen consumption, having strong correlations with the RPE-Borg scale. In the Older group, the RPE-color scale was significantly associated with heart rate, having moderate to high correlations with the RPE-Borg scale. The RPE-color scale demonstrated concurrent and construct validity in the Young women, as well as construct validity in Older adults.

Estado nutricional de crianças e adolescentes a partir do índice de massa corporal: concordância entre World Health Organization e International Obesity Task Force

Objective: To investigate the agreement between two international criteria for classification of children and adolescents nutritional status. Methods: The study included 778 girls and 863 boys aged from six to 13 years old. Body mass and height were measured and used to calculate the body mass index. Nutritional status was classified according to the cut-off points defined by the World Health Organization and the International Obesity Task Force. The agreement was evaluated using Kappa statistic and weighted Kappa. Results: In order to classify the nutritional status, the agreement between the criteria was higher for the boys (Kappa 0.77) compared to girls (Kappa 0.61). The weighted Kappa was also higher for boys (0.85) in comparison to girls (0.77). Kappa index varied according to age. When the nutritional status was classified in only two categories - appropriate (thinness + accentuated thinness + eutrophy) and overweight (overweight + obesity + severe obesity) -, the Kappa index presented higher values than those related to the classification in six categories. Conclusions: A substantial agreement was observed between the criteria, being higher in males and varying according to the age.Objective: To investigate the agreement between two international criteria for classification of children and ado - lescents nutritional status. Methods: ...

Glucose metabolism in discordant monozygotic twins for cardiorespiratory fitness

OBJECTIVE To determine if glucose and insulin concentrations are regulated by cardiorespiratory fitness (VO2max) regardless of their genetic effects. METHODS This cross-sectional study enrolled 38 pairs of young monozygotic twins (11 to 18 years-old). All subjects underwent a progressive maximal exercise test on a treadmill to determine the VO2max with gas exchange analysis (MedGraphics VO2000® - Medical Graphics Corp., St. Paul, MN). Blood samples were drawn after fasting to determine glucose and insulin levels. Monozygosity was confirmed by genotyping 15 informative genetic markers. Nine pairs had at least 10mL.kg-1.min-1 difference in VO2max and were divided into the more and less active group, according to their VO2max. Mean differences between more and less active groups were evaluated by Wilcoxons test for paired data. RESULTS On average, twins from the more active group presented a 17% (13.5±3.7mL.kg-1.min-1) higher VO2max compared to their less active siblings. No significant differences were observed between the groups for fasting insulin (36.5±34.6 versus 25.3±13.7mg/dL; p<0.813). However, the more active twins had lower fasting glucose than the less active ones (82.9±7.3 versus 86.7±7.6mg/dL; p<0.010). CONCLUSIONS In this case-control study (discordant monozygotic twins), the less active co-twins were characterized by higher fasting plasma glucose levels. This implies that poor cardiorespiratory fitness can be associated with defective glucose metabolism regardless of genetic factors.OBJETIVO: Verificar si las concentraciones de glucosa e insulina en ayuno son reguladas por la aptitud cardiorrespiratoria (VO2max), independiente de los efectos geneticos. METODOS: Datos de 38 pares de gemelos monocigoticos (11 a 18 anos) fueron analizados transversalmente. Los participantes fueron sometidos a una prueba de esfuerzo maximo con ergoespirometria abierta (MedGraphics VO2000® Medical Graphics Corp., St. Paul, MN) y a la recoleccion de sangre para estimar la concentracion de glucosa e insulina en ayuno. La cigosidad fue determinada por medio de la investigacion de concordancia de los gemelos respecto a 15 marcadores geneticos polimorficos. Nueve pares demostraron diferencia mediana intrapares para el consumo maximo de oxigeno ≥10mL.kg-1.min-1 y fueron divididos en dos grupos, de alta y baja aptitud. Los grupos fueron comparados a partir de la prueba pareada de Wilcoxon, teniendo en vista la asimetria de los datos. RESULTADOS: En promedio, los gemelos del grupo de alta aptitud presentaron consumo maximo de oxigeno el 17% superior (13,5±3,7mL.kg-1.min-1) a sus hermanos menos aptos. No hubo diferencia entre los grupos para las concentraciones de insulina (36,5±34,6 versus 25,3±13,7mg/dL; p<0,813), pero los gemelos mas aptos demostraron menor concentracion de glucosa que sus contrapares menos aptos (82,9±7,3 versus 86,7±7,6mg/dL; p<0,010, respectivamente). CONCLUSIONES: En este estudio, caracterizado como caso-control (gemelos monocigoticos discordantes), el hermano con menor aptitud cardiorrespiratoria presento mayor concentracion de glucosa en ayuno, sugiriendo que la baja aptitud cardiorrespiratoria esta asociada a disturbios en el metabolismo de glucosa.

Validity of the RAST for evaluating anaerobic power performance as compared to Wingate test in cycling athletes

El objetivo fue investigar la validad del teste de RAST (Running-based Anaerobic Sprint Test) en evaluar el desempeno de la potencia anaerobica traves del uso del teste de Wingate en ciclistas trenados. Participaron del estudio 10 ciclistas masculinos (28,0±7,3 anos) de la modalidad de Mountain bike. Despues de la mensuracion de las variables antropometricas, la potencia pico (PP), media (PM) y el indice de fatiga (IF) fueron determinados al acaso a partir de dos testes de Wingate y de dos testes de RAST. Fueron utilizados el test t independiente de Student, el analisis de correlacion linear de Pearson (r) y el test de Bland-Altman. Los resultados demostraron, contrariamente al IF (33.8±4.6% vs. 37.8±7.9%; r=0.172), diferencias significativas entre el teste de Wingate y el RAST para PP y PM (W.kg-1 e W). Mismo que los valores de correlacion de PP e PM (W) tengan sido fortes (0,831 e 0,714, respectivamente), la concordancia entre los protocolos de Wingate y RAST fue baja, sugiriendo que el teste de RAST no es valido para evaluar el desempeno de la potencia anaerobica a partir del teste de Wingate en este grupo.O objetivo foi investigar a validade do teste de RAST (Running-based Anaerobic Sprint Test) em avaliar o desempenho da potencia anaerobia a partir do teste de Wingate em ciclistas treinados. Participaram do estudo 10 ciclistas do sexo masculino (28,0±7,3 anos) da modalidade de Mountain bike. Apos a mensuracao das variaveis antropometricas, a potencia pico (PP), media (PM) e o indice de fadiga (IF) foram determinados randomicamente a partir de dois testes de Wingate e dois testes de RAST. Foram utilizados o teste t independente de Student, a analise de correlacao linear de Pearson (r) e o teste de Bland-Altman. Os resultados demonstraram, exceto para o IF (33.8±4.6% vs. 37.8±7.9%; r=0.172), diferencas significativas entre o teste de Wingate e o RAST para PP e PM (W.kg-1 e W). Embora os valores de correlacao para a PP e PM (W) tenham sido fortes (0.831 e 0.714, respectivamente) a concordância entre os protocolos de Wingate e RAST foi baixa, sugerindo que o teste de RAST nao e valido para avaliar o desempenho da potencia anaerobica a partir do teste de Wingate em ciclistas.

Desempenho em testes de força estática: comparação entre trabalhadores hipertensos e normotensosMuscular static strength test performance: comparison between normotensive and hypertensive workers

OBJECTIVE: The aim of the study was to compare static muscular strength test performance between hypertensive and normotensive workers, considering the hypothesis that hypertensive individuals have lower strength than normotensive individuals. METHODS: The participants consisted of 354 workers (246 men and 108 women) who underwent height, body mass, waist circumference, systolic and diastolic blood pressure (BP) measurements, as well as right and left handgrip, and scapular and lumbar strength tests. Assessments were performed during three days in all three shifts, with workers from a candy and sweets factory located in Rio Claro, SP, Brazil. BP measurements were performed with a 10-minute interval, with the subject in the sitting position. Before the strength tests were performed, the workers were familiarized with the equipment; the highest value was recorded after two attempts at each test. RESULTS: The results showed significant differences between hypertensive and normotensive individuals for age, body mass, body mass index, and waist circumference greater for hypertensive individuals. Regarding static muscle strength tests performance, the hypertensive individuals did not differ significantly from normotensive individuals; however, this difference was observed when groups divided by body mass index (BMI) were compared. The obesity group had strength values above those of the normal weight/overweight group among normotensive individuals, but this was not observed among the hypertensive individuals. As for the intragender comparison, there were no significant differences for the strength tests. CONCLUSION: Normotensive and hypertensive workers showed no significant differences in the performance of static muscular strength tests; however, body mass and gender seem to affect the association between muscle strength and blood pressure.OBJECTIVE The aim of the study was to compare static muscular strength test performance between hypertensive and normotensive workers, considering the hypothesis that hypertensive individuals have lower strength than normotensive individuals. METHODS The participants consisted of 354 workers (246 men and 108 women) who underwent height, body mass, waist circumference, systolic and diastolic blood pressure (BP) measurements, as well as right and left handgrip, and scapular and lumbar strength tests. Assessments were performed during three days in all three shifts, with workers from a candy and sweets factory located in Rio Claro, SP, Brazil. BP measurements were performed with a 10-minute interval, with the subject in the sitting position. Before the strength tests were performed, the workers were familiarized with the equipment; the highest value was recorded after two attempts at each test. RESULTS The results showed significant differences between hypertensive and normotensive individuals for age, body mass, body mass index, and waist circumference greater for hypertensive individuals. Regarding static muscle strength tests performance, the hypertensive individuals did not differ significantly from normotensive individuals; however, this difference was observed when groups divided by body mass index (BMI) were compared. The obesity group had strength values above those of the normal weight/overweight group among normotensive individuals, but this was not observed among the hypertensive individuals. As for the intragender comparison, there were no significant differences for the strength tests. CONCLUSION Normotensive and hypertensive workers showed no significant differences in the performance of static muscular strength tests; however, body mass and gender seem to affect the association between muscle strength and blood pressure.

Metabolismo de glicose em gêmeos monozigóticos discordantes para aptidão cardiorrespiratória

OBJECTIVE To determine if glucose and insulin concentrations are regulated by cardiorespiratory fitness (VO2max) regardless of their genetic effects. METHODS This cross-sectional study enrolled 38 pairs of young monozygotic twins (11 to 18 years-old). All subjects underwent a progressive maximal exercise test on a treadmill to determine the VO2max with gas exchange analysis (MedGraphics VO2000® - Medical Graphics Corp., St. Paul, MN). Blood samples were drawn after fasting to determine glucose and insulin levels. Monozygosity was confirmed by genotyping 15 informative genetic markers. Nine pairs had at least 10mL.kg-1.min-1 difference in VO2max and were divided into the more and less active group, according to their VO2max. Mean differences between more and less active groups were evaluated by Wilcoxons test for paired data. RESULTS On average, twins from the more active group presented a 17% (13.5±3.7mL.kg-1.min-1) higher VO2max compared to their less active siblings. No significant differences were observed between the groups for fasting insulin (36.5±34.6 versus 25.3±13.7mg/dL; p<0.813). However, the more active twins had lower fasting glucose than the less active ones (82.9±7.3 versus 86.7±7.6mg/dL; p<0.010). CONCLUSIONS In this case-control study (discordant monozygotic twins), the less active co-twins were characterized by higher fasting plasma glucose levels. This implies that poor cardiorespiratory fitness can be associated with defective glucose metabolism regardless of genetic factors.OBJETIVO: Verificar si las concentraciones de glucosa e insulina en ayuno son reguladas por la aptitud cardiorrespiratoria (VO2max), independiente de los efectos geneticos. METODOS: Datos de 38 pares de gemelos monocigoticos (11 a 18 anos) fueron analizados transversalmente. Los participantes fueron sometidos a una prueba de esfuerzo maximo con ergoespirometria abierta (MedGraphics VO2000® Medical Graphics Corp., St. Paul, MN) y a la recoleccion de sangre para estimar la concentracion de glucosa e insulina en ayuno. La cigosidad fue determinada por medio de la investigacion de concordancia de los gemelos respecto a 15 marcadores geneticos polimorficos. Nueve pares demostraron diferencia mediana intrapares para el consumo maximo de oxigeno ≥10mL.kg-1.min-1 y fueron divididos en dos grupos, de alta y baja aptitud. Los grupos fueron comparados a partir de la prueba pareada de Wilcoxon, teniendo en vista la asimetria de los datos. RESULTADOS: En promedio, los gemelos del grupo de alta aptitud presentaron consumo maximo de oxigeno el 17% superior (13,5±3,7mL.kg-1.min-1) a sus hermanos menos aptos. No hubo diferencia entre los grupos para las concentraciones de insulina (36,5±34,6 versus 25,3±13,7mg/dL; p<0,813), pero los gemelos mas aptos demostraron menor concentracion de glucosa que sus contrapares menos aptos (82,9±7,3 versus 86,7±7,6mg/dL; p<0,010, respectivamente). CONCLUSIONES: En este estudio, caracterizado como caso-control (gemelos monocigoticos discordantes), el hermano con menor aptitud cardiorrespiratoria presento mayor concentracion de glucosa en ayuno, sugiriendo que la baja aptitud cardiorrespiratoria esta asociada a disturbios en el metabolismo de glucosa.