Responsiveness on metabolic syndrome criteria and hepatic parameters after 12 weeks and 24 weeks of multidisciplinary intervention in overweight adolescents.

PURPOSE: This study aimed to evaluate the effect and individual responsiveness after 12 (12wk) and 24 weeks (24wk) of physical exercise (PE) and nutritional guidance (NG) on metabolic syndrome (MetS) criteria and hepatic parameters in overweight adolescents. METHODS: The study comprised 94 overweight adolescents, aged between 10 and 16 years old, from both sexes, allocated into groups: PE and NG (PENGG, n = 64) and control with NG (NGCG, n = 30). Variables were collected at baseline, 12wk, and 24wk. Weight, height, abdominal circumference (AC), blood pressure, and peak oxygen consumption (VO2peak), as well as insulin, triglycerides (TAG), high-density lipoprotein (HDL-c), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated. HOMA-IR and QUICKI were calculated. PE session consisted of 45 min of indoor cycling, 45 min of walking, and 20 min of stretching, three times a week. The NG consisted of three collective sessions in the first 12wk. Anova, effect size, and prevalence of responders were used for statistical analysis. RESULTS: The PENGG12wk reduced anthropometric and metabolic measurements, while increased VO2peak and HDL-c. The PEG24wk promoted anthropometric, blood pressure, metabolic, and VO2peak improvements, but participants without PE returned to pre-exercise status and presented worsening AST and ALT concentrations. Frequencies of respondents in PENGG12wk versus (vs) NGCG12wk were, respectively, AC (69.1% vs 17.6%, p < 0.01), HDL-c (87.2% vs 23.5%, p < 0.01), TAG (67.3% vs 41.7%, p = 0.05) and ALT (45.5% vs 5,9%; p = 0.003). CONCLUSION: Interventions with PE were effective to reduce MetS components in 12wk and maintenance in 24wk, showing anthropometric, metabolic, and VO2peak improvements. Higher individual responses were observed in 12wk and in 24wk, important changes in overweight adolescent's therapy. LEVEL OF EVIDENCE: Level I, evidence obtained from well-designed controlled trials randomization. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: Brazilian Registry of Clinical Trials (RBR-4v6h7b) and date of registration April 4th, 2020.

Distance from home to the nearest park and the use of the parks for physical activity: the mediator role of road safety perception in adolescents.

OBJECTIVE: The objective of the study is to examine whether adolescents' road safety perception (RSP) acts as a mediator on the association between the distance from home to the nearest park and the use of the parks for physical activity (PA). STUDY DESIGN: This is a cross-sectional study. METHODS: The evaluation was through a random sample of 1130 adolescents (534 male), corresponding to 47.3%, 14-20 years old, from Porto Alegre, Brazil. RSP was assessed through some questions of the Neighborhood Environment Walkability Scale for Youth. Park use, socioeconomic status, age, and sex were measured using a questionnaire. Distance from home to the nearest park was evaluated through geographic information system. Data analysis was performed using Pearson correlation, and linear regression models were fitted as per the Baron and Kenny procedures for mediation analyses. All analyses were adjusted for sex and socioeconomic status. RESULTS: Road safety perception is independently associated with less distance from home to the nearest park (P = 0.04) and use of the parks for PA (P = 0.02). Road safety perception is a mediator and explains 16% of the association between park use and distance from home to the park (indirect Effect = -40.9966; 95% confidence interval [CI]: 119.3733-2.2455). CONCLUSION: Our findings indicated that RSP is a mediator on the association between the distance from home to the nearest park and the use of the parks for PA. Future studies should take this into consideration frequency and intensity of PA and other environmental characteristics, such as crime, aesthetics, and neighborhood facilities.

3 Different types of strength training in older women.

The objective of the present study was to evaluate and compare the neuromuscular, morphological and functional adaptations of older women subjected to 3 different types of strength training. 58, healthy women (67 ± 5 year) were randomized to experimental (EG, n=41) and control groups (CG, n=17) during the first 6 weeks when the EG group performed traditional resistance exercise for the lower extremity. Afterwards, EG was divided into three specific strength training groups; a traditional group (TG, n=14), a power group (PG, n=13) that performed the concentric phase of contraction at high speed and a rapid strength group (RG, n=14) that performed a lateral box jump exercise emphasizing the stretch-shortening-cycle (SSC). Subjects trained 2 days per week through the entire 12 weeks. Following 6 weeks of generalized strength training, significant improvements occurred in EG for knee extension one-repetition (1RM) maximum strength (+19%), knee extensor muscle thickness (MT, +15%), maximal muscle activation (+44% average) and onset latency ( -31% average) for vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) compared to CG (p<0.05). Following 6 more weeks of specific strength training, the 1RM increased significantly and similarly between groups (average of +21%), as did muscle thickness of the VL (+25%), and activation of VL (+44%) and VM (+26%). The onset latency of RF (TG=285 ± 109 ms, PG=252 ± 76 ms, RG=203 ± 43 ms), reaction time (TG=366 ± 99 ms, PG=274 ± 76 ms, RG=201 ± 41 ms), 30-s chair stand (TG=18 ± 3, PG=18 ± 1, RG=21 ± 2) and counter movement jump (TG=8 ± 2 cm, PG=10 ± 3 cm, RG=13 ± 2 cm) was significantly improved only in RG (p<0.05). At the end of training, the rate of force development (RFD) over 150 ms (TG=2.3 ± 9.8 N·s(-1), PG=3.3 ± 3.2 N·s(-1), RG=3.8 ± 6.8 N·s(-1), CG=2.3 ± 7.0 N·s(-1)) was significantly greater in RG and PG than in TG and CG (p<0.05). In conclusion, rapid strength training is more effective for the development of rapid force production of muscle than other specific types of strength training and by consequence, better develops the functional capabilities of older women.