Exercise order influences number of repetitions and lactate levels but not perceived exertion during resistance exercise in adolescents.

The purpose of this study was to analyze the effects of resistance training (RT) order on number of repetitions, total training volume, ratings of perceived exertion (RPE), and the lactate response in male adolescents. Twelve adolescents (age: 15.7 ± 1.4 yrs) completed two RT sessions in a counterbalanced crossover design: one with exercises for smaller muscle groups followed by larger muscle groups (SM-LM), whereas the other session was performed in the opposite sequence (LM-SM). The exercise order for SM-LM was standing triceps extension (TE), dumbbell biceps curl (BC), bench press (BP), and seated row machine (RM), while the order for LM-SM was the opposite. Subjects performed three sets of a predetermined 10 repetition maximum for each exercise. Total repetitions completed for each exercise and RPE were assessed after each set, and blood lactate (BL) was measured before RT, 1 m after the first exercise, 1 m after the third exercise, and 10 m after each RT session. Blood lactate (BL) was higher for the LM-SG compared with SM-LM 10 m after exercise (7.4 ± 1.8 versus 6.5 ± 2.1 mmol/L; p < 0.05). More repetitions were completed on the TE and BC in the SM-LM compared with LM-SG (24.9 ± 3.4 and 16.2 ± 3.2 versus 16.3 ± 4.2 and 14.6 ± 3.0, respectively; p < 0.02), while more repetitions were completed on the BP and RM following the LM-SM (14.3 ± 2.3 and 23.4 ± 4.5 versus 12.4 ± 4.2 and 13.6 ± 5.1, respectively; p < 0.02). No differences were found for RPE. It may be appropriate to perform multijoint exercises first to improve general coordination and force, while the use of smaller muscle groups first may be interesting to target specific muscle weaknesses.

Avaliação da pressão arterial em mulheres sedentárias e sua relação com a força muscular / Evaluation of sedentary women's ambulatory blood pressure and its relation to muscle strength

Objetivo: Comparar a pressão arterial ambulatorial em mulheres com diferentes valores de força muscular relativa. Métodos: Dados de 21 (33,8±8,0 anos) mulheres sedentárias da Vila Telebrasília foram coletados durante o período de novembro de 2010 a julho de 2011. As voluntárias foram submetidas à avaliação de força de preensão manual e à monitorização ambulatorial da pressão arterial (MAPA), respeitando um período de 72 horas. Após a avaliação de força de preensão manual, para determinação da força muscular absoluta, foi realizado o ajuste em relação ao peso, para determinação da força muscular relativa. A amostra foi dividida em três tercis, de acordo com os valores de força muscular relativa, para efeito de comparação da pressão arterial sistólica, diastólica e média durante os períodos de 24 horas, noturno e diurno, através de uma ANOVA one-way, seguida, quando apropriado, do teste de Bonferroni, com nível de significância de p<0,05. Resultados: Diferenças significativas (p<0,05) foram encontradas para os valores de pressão arterial sistólica entre o tercil 1 (99,3±12,2) e o tercil 3 (106,8±11,1) no período noturno. Os valores de pressão arterial média também apresentaram diferenças significativas (p<0,05) entre o tercil 1 (70,2 ±6,3) e o tercil 3 (80,3±8,8). Conclusão: Mulheres com maior força muscular relativa apresentam menores valores de pressão arterial durante o período noturno.

Objective: To compare the ambulatory blood pressure in women with different values of relative muscle strength. Methods: Data from 21 (aged 33.8±8.0 years) sedentary women from Vila Telebrasília was collected during the period of November 2010 to July 2011. The volunteers were submitted to the evaluation of the handgrip strength and ambulatory monitoring of blood pressure (AMBP) for a 72-hour period. Following the evaluation of handgrip strength to determine the absolute muscle strength, an adjustment in the body mass was made, in order to determine the relative muscle strength. Based on the relative value of muscular strength, the sample was divided into tertiles to compare systolic, diastolic and mean blood pressure during the periods of 24 hours, daytime and night-time, by using an one-way ANOVA, followed by Bonferroni test when appropriate, with a significance level of p<0.05. Results: Significant differences were found for systolic blood pressure between tertile 1 (99.3±12.2) and tertile 3 (106.8±11.1) in the night-time (P<0.05). Values of mean blood pressure were also significantly different between tertile 1 (70.2±6.3) and tertile 3 (80.3 ± 8.8) in the night-time (p<0,05). Conclusion: Women with higher relative muscle strength present lower values of blood pressure during night-time.

Relação da circunferência do pescoço com a força muscular relativa e os fatores de risco cardiovascular em mulheres sedentárias / Relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women

OBJETIVO: O objetivo do presente estudo foi verificar a relação da circunferência do pescoço com a força muscular relativa e os fatores de risco cardiovascular em mulheres sedentárias. MÉTODOS: Estudo transversal, realizado com 60 mulheres pré-menopausadas (33,9±9,1 anos; 67,4±13,6kg; 1,57±0,06cm e 27,2±5,3kg/m²). Com base no valor da circunferência do pescoço, a amostra foi dividida em dois grupos: Grupo Circunferência <35cm (n=27) e Grupo Circunferência >35cm (n=33), para efeito de comparação da força muscular relativa e dos fatores de risco cardiovascular. A correlação entre as variáveis foi testada por meio da correlação de Pearson e de Spearman; o nível de significância foi estabelecido em p<0,05. RESULTADOS: Os resultados demonstram que as mulheres com circunferência do pescoço >35cm apresentaram maiores valores de massa corporal, circunferência da cintura, índice de adiposidade corporal, índice de massa corporal, pressão arterial sistólica, glicemia, hemoglobina glicada e volume de gordura visceral, quando comparadas ao grupo com circunferência do pescoço <35cm. Adicionalmente, o grupo com maior circunferência do pescoço apresentou menores valores de força relativa. CONCLUSÃO: A circunferência do pescoço parece ser um importante fator de predição de risco cardiovascular e perda de força relativa em mulheres sedentárias de meia idade.

OBJECTIVE: To verify the relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women. METHODS: A cross-sectional study with 60 premenopausal women (33.9±9.1 years; 67.4±13.6kg; 1.57±0.6cm and 27.2±5.3kg/m²). Based on the neck circumference, the sample was divided into two groups: Group Circumference <35cm (n=27) and Group Circumference >35cm (n=33) to compare relative muscle strength and cardiovascular risk factors. The correlation between variables was tested by Pearson and Spearman correlations, with a significance level established at p<0.05. RESULTS: The findings revealed that women with neck circumference >35cm presented higher values of body mass, waist circumference, body adiposity index, body mass index, systolic blood pressure, blood glucose, glycated hemoglobin and volume of visceral fat when compared with the group with neck circumference <35cm. Additionally, the group with larger neck circumference presented lower values of relative strength. CONCLUSION: Neck circumference seems to be an important predictive factor of cardiovascular risk and of relative strength loss in middle-aged sedentary women.

Relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women.

OBJECTIVE: To verify the relation of neck circumference and relative muscle strength and cardiovascular risk factors in sedentary women. METHODS: A cross-sectional study with 60 premenopausal women (33.9±9.1 years; 67.4±13.6kg; 1.57±0.6cm and 27.2±5.3kg/m²). Based on the neck circumference, the sample was divided into two groups: Group Circumference <35cm (n=27) and Group Circumference >35cm (n=33) to compare relative muscle strength and cardiovascular risk factors. The correlation between variables was tested by Pearson and Spearman correlations, with a significance level established at p<0.05. RESULTS: The findings revealed that women with neck circumference >35cm presented higher values of body mass, waist circumference, body adiposity index, body mass index, systolic blood pressure, blood glucose, glycated hemoglobin and volume of visceral fat when compared with the group with neck circumference <35cm. Additionally, the group with larger neck circumference presented lower values of relative strength. CONCLUSION: Neck circumference seems to be an important predictive factor of cardiovascular risk and of relative strength loss in middle-aged sedentary women.