RESUMO
BACKGROUND: Despite the positive effects of high-intensity training on weight management and health-related outcomes, it is postulated that high-intensity training may also induce oxidative stress, increasing hepatic damage. AIM: The aim of this study was to compare the effects of low versus high-intensity training on biomarkers related to non-alcoholic fatty liver disease (NAFLD) in adolescents with obesity. METHODS: For this study 107 adolescents (15 ± 1 years) with obesity (BMI = 34.7 ± 4.1 kg/m2) were randomized into High-Intensity Training (HIT, n = 31), Low-Intensity Training (LIT, n = 31) or Control Group (CG, n = 45). Adolescents from HIT and LIT received nutritional, psychological and clinical counseling. Blood lipids, Castelli risk index, glucose, insulin and hepatic enzymes were measured at baseline and after 12 weeks. RESULTS: Castelli risk index 1 was reduced in all groups ( p < 0.001) with moderate effect size ( d) for HIT ( d = 0.62) and LIT ( d = 0.66). Castelli risk index 2 also decreased ( p < 0.001 for all groups; HIT d = 0.65; LIT d = 0.79). High-density lipoprotein increased in all groups ( d = 0.25 and d = 0.18 in HIT and LIT), while alanine aminotransferase tended to reduce ( p = 0.062) in HIT ( d = 0.34) and LIT ( d = 0.73) and aspartate aminotransferase decreased ( p = 0.024) in both HIT ( d = 0.24) and LIT ( d = 0.45). There were no changes in glucose, insulin and insulin resistance. CONCLUSION: Both high and low-intensity training improved biomarkers related to NAFLD. Thus, high-intensity training can be a safe and effective alternative to prevent and treat NAFLD in adolescents with obesity.
Assuntos
Treinamento Intervalado de Alta Intensidade , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Obesidade Infantil/terapia , Condicionamento Físico Humano , Adolescente , Comportamento do Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Biomarcadores/sangue , Índice de Massa Corporal , Brasil , Terapia Combinada/efeitos adversos , Dieta Saudável , Dieta Redutora , Feminino , Treinamento Intervalado de Alta Intensidade/efeitos adversos , Humanos , Pesquisa Interdisciplinar , Masculino , Motivação , Hepatopatia Gordurosa não Alcoólica/etiologia , Ciências da Nutrição/educação , Cooperação do Paciente , Educação de Pacientes como Assunto , Obesidade Infantil/sangue , Obesidade Infantil/dietoterapia , Obesidade Infantil/fisiopatologia , Condicionamento Físico Humano/efeitos adversos , Psicoterapia de GrupoRESUMO
The aim of this study was to determine whether rating of perceived exertion (RPE) is a valid method to control the effort during the circuit weight training (CWT) in trained men. Ten men (21.3 ± 3.3 years) with previous experience in resistance training (13.1 ± 6.3 months) performed 3 sessions: 1 orientation session and 2 experimental sessions. The subjects were randomly counterbalanced to 2 experimental sessions: CWT or multiple-set resistance training (control). In both sessions, 8 exercises (bench press, leg press 45°, seated row, leg curl, triceps pulley, leg extension, biceps curl, and adductor chair) were performed with the same work: 60% of 1 repetition maximum, 24 stations (3 circuits) or 24 sets (3 sets/exercise), 10 repetitions, 1 second in the concentric and eccentric phases, and rest intervals between sets and exercise of 60 seconds. Active muscle RPEs were measured after each 3 station/sets using the OMNI-Resistance Exercise Scale (OMNI-RES). In this same time, blood lactate was collected. Compared with baseline, both levels of blood lactate and RPE increased during whole workout in both sessions, the RPE at third, 23rd, and 27th minute and the blood lactate at third, seventh, 11th, 15th, 27th, and 31st minute were higher in multiple set compared with CWT. Positive correlation between blood lactate and RPE was observed in both experimental sessions. The results indicated that the RPE is a valid method to control the effort during the CWT in trained men and can be used to manipulate the intensity without the need to perform invasive assessments.