The influence of high-intensity interval training on anthropometric variables of adults with overweight or obesity: a systematic review and network meta-analysis.

OBJECTIVE: The goal of this study was to evaluate the influence of high-intensity interval training (HIIT) on anthropometric variables in adults afflicted with overweight or obesity and to compare the effects with those of moderate-intensity continuous training. METHODS: A computer literature search was performed for HIIT intervention studies that evaluated anthropometric variables in adults afflicted with overweight or obesity. RESULTS: Of the 857 articles retrieved in the electronic search, 48 met the inclusion criteria. The analyses demonstrated that HIIT was effective in decreasing body mass (-1.45 kg [95% CI: -1.85 to -1.05 kg]), body mass index (-0.44 kg m-2 [95% CI: -0.59 to -0.30 kg m-2 ]), waist circumference (-2.3 cm [95% CI: -3.1 to -1.4 cm]), waist/hip ratio (-0.01 [95% CI: -0.02 to -0.00]), body fat percentage (-1.29% [95% CI: -1.70% to -0.87%]) and abdominal visceral fat area (-6.83 cm2 [95% CI: -11.95 to -1.71 cm2 ]). When considering equalization between the two methods (energy expenditure or workload matched), no differences were found in any measure except body mass (for which HIIT was superior). CONCLUSIONS: High-intensity interval training and moderate-intensity continuous training results were similar, particularly when equalization between the two methods was considered. Thus, HIIT can be used as a secondary method for the treatment of obesity in adults.

Influence of the aerobic fitness on time spent at high percentage of maximal oxygen uptake during a high-intensity intermittent running.

This study aimed to evaluate absolute and relative (%V.O2max) oxygen uptake (total, during effort and pause), and time spent above 90% of V.O2max during high-intensity intermittent running in subjects with different training status. Fourteen males were evaluated and divided (moderate and high aerobic power) according to their V.O2max obtained in an incremental treadmill test to volitional exhaustion. They were then submitted to high-intensity intermittent aerobic exercise (1 min:1 min at maximum velocity attained during the treadmill test, totalling 4 km). A Student's t test for independent data was conducted to identify differences between groups. The moderate aerobic power group spent more time above 90% V.O2max compared to the high aerobic power group (30.2 ±9.1%; 7.3±6%, respectively, P=0.001). Moreover, the moderate aerobic power group presented lower V.O2total (P=0.011), V.O2effort (P=0.007), higher V.O2total (%V.O2), V.O2effort (P<0.001), V.O2pause (V.O2max%) (P=0.006) compared with the high aerobic power group. There was no difference in V.O2pause between groups (P=0.091), the difference between V.O2 effort and pause was greater for the high aerobic power group compared with the moderate group (4.4±2.1; 7.8±2 mL.kg-1.min-1; P=0.009) and the difference between V.O2 effort and pause (%V.O2max) was not different between groups. To conclude, these results demonstrated that individuals with better aerobic fitness spent less time above 90% of the V.O2max and that this response can be due to better capacity to recover during the pause.

Caracterização da condição física e fatores de risco cardiovascular de policiais militares rodoviários / Caracterización de la condición física y factores del riesgo cardiovascular de la policía de carreteras / Characterization of the physical condition and cardiovascular risk of highway police officers

Objetivo: O objetivo do presente estudo foi verificar os níveis de condição, composição corporal e pressão arterial de policiais rodoviários do estado do Paraná - Brasil. Método: Fizeram parte da amostra 52 oficiais do sexo masculino (idade: 38,3 ± 6,3 anos, massa corporal: 89,6 ± 18,4 kg) de diferentes patentes. Foram realizadas diversas mensurações para obtenção do índice de massa corporal (IMC), circunferência de cintura (CC), relação cintura/quadril (RCQ), composição corporal por meio da espessura de dobras cutâneas, potência aeróbia estimada indiretamente em teste de esforço ergométrico, resistência muscular localizada (RML) de membros superiores e abdominal e os níveis pressóricos foram aferidos por método auscultatório. Resultados: Considerando as variáveis analisadas, os policiais rodoviários apresentaram IMC de 28,6 ± 4,8 kg/m2, risco cardiovascular elevado (95,4 ± 10,8 cm) para CC e alto (0,92 ± 0,05) para RCQ. O percentual de gordura corporal apresentou-se acima dos valores recomendáveis (23,6 ± 4,3 %) para saúde, a potência aeróbia estimada foi considerada boa (34,8 ± 1,1 ml/kg/min), a RML de membros superiores (21 ± 8 repetições) e foi obtida por realização dos testes de abdominal e flexão de braço, respectivamente (28 ± 8 repetições) foram classificadas como média e uma parcela importante dos oficiais (23 %) mostraram-se com níveis pressóricos elevados. Conclusão: Os policiais militares rodoviários mostraram-se com níveis inadequados de condição física, apresentando excesso de peso e adiposidade corporais, e, uma parcela importante, exibiu níveis pressóricos elevados, sugerindo elevado risco cardiovascular

Objetivo. Evaluar los niveles de aptitud, composición corporal y de la presión arterial de la policía de carreteras en el estado de Paraná, Brasil. Método. Se analizó a 52 oficiales del sexo masculino (38,3 ± 6,3 años, y 89,6 ± 18,4 kg). Fueron realizadas diferentes mediciones para la obtención del índice de masa corporal (IMC); la circunferencia de cintura (CC); el índice cintura/cadera (ICC). La composición corporal se midió por medio del espesor del pliegue cutáneo; la potencia aeróbica se estimó indirectamente mediante una prueba de esfuerzo en una cinta ergométrica; la fuerza muscular de los miembros superiores se midió mediante el número de flexiones y la del abdomen por el número de abdominales y la presión arterial fue medida por auscultación. Resultados. Los policías presentaban un IMC clasificado como obesidad leve (28,6 ± 4,8 kg/m2); la CC de alto riesgo (95,4 ± 10,8 cm); el ICC alto (0,92 ± 0,05); el porcentaje de grasa corporal por encima de los valores recomendados (23,6 ± 4,3 %); la potencia aeróbica buena (34,8 ± 1,1 ml/kg/min); la RM de los miembros superiores (21 ± 8 repeticiones) y del abdomen (28 ± 8 repeticiones) medias, y una proporción significativa (23 %) de los policías presentaron niveles de presión arterial alterada. Conclusión. En base a estos resultados, fue posible verificar que aunque la policía ha mantenido buenos niveles de potencia aeróbica y fuerza muscular, presentaron exceso de peso e índices que indican alto riesgo cardiovascular (AU)

Objective. The aim of this study was to assess the physical fitness, body composition and blood pressure of highway police officers in the state of Paraná, Brazil. Method. The sample consisted of 52 male (38.3 ± 6.3 years old, 89.6 ± 18.4 kg) where the following determinations were performed: body mass index (BMI); waist circumference (WC); waist/hip ratio (WHR); body composition (skinfold thickness); aerobic power (indirectly estimated in a treadmill test); muscle strength of the upper limbs was measured by the number of push-ups and abdominal strength by the number of crunches (ES) and blood pressure (measured by auscultatory method). Results. The highway police officers had a BMI classified as mild obesity (28.6 ± 4.8 kg/m2), and a higher cardiovascular risk as determined by WC (95.4 ± 10.8 cm) and WHR (0.92 ± 0.05). The percentage of body fat was above the recommended values (23.6 ± 4.3 %) but the aerobic power was considered good (34.8 ± 1.1 ml/kg/min). Mean ES upper body (21 ± 8 repetitions) and abdomen (28 ± 8 repetitions) were qualified as fair but mean blood pressure was considered high in 23 % of the police officers. Conclusion. Based on our results it was possible to conclude that although the police officers presented good levels of aerobic power and muscle strength, they are overweight and showed a higher cardiovascular risk (AU)

Maximum number of repetitions, total weight lifted and neuromuscular fatigue in individuals with different training backgrounds.

The aim of this study was to evaluate the performance, as well as neuromuscular activity, in a strength task in subjects with different training backgrounds. Participants (n = 26) were divided into three groups according to their training backgrounds (aerobic, strength or mixed) and submitted to three sessions: (1) determination of the maximum oxygen uptake during the incremental treadmill test to exhaustion and familiarization of the evaluation of maximum strength (1RM) for the half squat; (2) 1RM determination; and (3) strength exercise, four sets at 80% of the 1RM, in which the maximum number of repetitions (MNR), the total weight lifted (TWL), the root mean square (RMS) and median frequency (MF) of the electromyographic (EMG) activity for the second and last repetition were computed. There was an effect of group for MNR, with the aerobic group performing a higher MNR compared to the strength group (P = 0.045), and an effect on MF with a higher value in the second repetition than in the last repetition (P = 0.016). These results demonstrated that individuals with better aerobic fitness were more fatigue resistant than strength trained individuals. The absence of differences in EMG signals indicates that individuals with different training backgrounds have a similar pattern of motor unit recruitment during a resistance exercise performed until failure, and that the greater capacity to perform the MNR probably can be explained by peripheral adaptations.