Increasing prevalence of sedentary behavior (SB) combined with low levels of physical activity (PA) in children and adolescents has become a growing public health concern. Therefore, this study aimed to identify the daily behavioral pattern of adolescents and examine the isotemporal substitution effects of SB with light-intensity PA (LIPA) or moderate-to-vigorous PA (MVPA) on cardiometabolic markers. In this cross-sectional study, the daily behavioral pattern of Brazilian male adolescents was objectively measured for 7 days. Vector magnitude activity counts were used to estimate SB, LIPA, and MVPA with cut-points specifically validated for youth. The isotemporal substitution model was used to assess the effects of replacing different SB bouts (5, 10, 30, and 60 min) with LIPA or MVPA on cardiometabolic markers [body mass index, waist circumference, body fat percentage (BF%), total cholesterol, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, low-density lipoprotein cholesterol, triglyceride (TG), glucose, insulin, homeostatic model assessment of insulin resistance (HOMA2-IR), insulin sensitivity (HOMA2-S), beta cell function (HOMA2-β), systolic-blood pressure (SBP), diastolic-blood pressure, and cardiometabolic risk score]. Male adolescents (n = 84; age, 16.7 ± 0.9 years) wore the GT3X+ for 6.7 ± 0.6 days, during 15.2 ± 2.3 h, and spent 72.9% of the time in SB, 17.3% in LIPA, and 9.8% in MVPA. SB replacement with LIPA was associated with increased HDL-C, TG, HOMA2-IR, and HOMA2-S and decreased SBP. In contrast, SB replacement with MVPA was associated with decreased BF%. Therefore, our findings suggest that replacing SB with LIPA showed positive results on HDL-C, HOMA2-S and SBP, while replacing SB with MVPA was associated with only one obesity indicator (BF%). Moreover, participants met the daily MVPA recommendations, but they still had a daily behavioral pattern with high SB. In this context, LIPAs can be considered an effective alternative to reduce SB and improve the health indicators of this population.

Although exercise promotes beneficial effects in diabetic patients, some studies have questioned the degree of their importance in terms of the increase in total energy expenditure. In these studies, the decrease of physical activity levels (PAL) was referred as "compensatory effect of exercise". However, our aim was to investigate whether aerobic exercise has compensatory effects on PAL in type 2 diabetes patients. Eight volunteers (51.1 ± 8.2 years) were enrolled in a supervised exercise programme for 8 weeks (3 d · wk(-1), 50-60% of VO2 peak for 30-60 min). PAL was measured using tri-axial accelerometers in the 1st, 8th and 12th weeks. Biochemical tests, cardiorespiratory fitness, anthropometric assessment and body composition were measured in the 2nd and 11th weeks. Statistical analysis was performed using non-parametric tests (Friedman and Wilcoxon, P < 0.05). We found no significant differences in PAL between intervention periods, and participants spent the majority of their awake time in sedentary activities. However, the exercise programme generated a significant 14.8% increase in VO2 peak and a 15% reduction in fructosamine. The exercise programme had no compensatory effects on PAL in type 2 diabetes patients, but improved their cardiorespiratory fitness and glycaemic control.

BackgroundGlycated hemoglobin (A1C) and Fasting Plasma Glucose (FPG) are the two monitoring blood glucose tests most frequently used. However, both methods are shown to be insensitive to detect glycemic variations in short duration periods. Therefore, we aimed to assess the effect of a short-term exercise program on glycemic levels measured by fructosamine concentrations in type 2 diabetes patients.MethodsEight volunteers (51.1 ± 8.2 years) underwent a supervised exercise program during eight weeks (3 d.wk-1, 50-60% of VO2 peak for 30–60 minutes). The body composition, VO2 peak, A1C, FPG, fructosamine and capillary blood glucose (CBG) were evaluated. We used ANOVA - One Way for repeated measures followed by Tukey post-hoc test and paired t test. P values <0.05 were considered significant.ResultsWe found statistical differences on the concentrations of fructosamine, VO2 peak and CBG. However, A1C and FPG showed no statistical difference. Fructosamine declined by 15% (57 μmol/L) between the beginning and the end of the study. Individually, 50% of the sample reached the reference values for the normality in fructosamine test. VO2 peak increased by 14.8% (3.8 ml.kg-1.min-1) and CBG decreased on an average of 34.4% (69.3 mg/dL).ConclusionsFructosamine test is effective in the evaluation of glucose with type 2 diabetes patients when undergoing a short exercise program, alternatively to the traditional A1C and FPG assessment. Our results are relevant in clinical practice, because the significant improvement in glycemic status can help to evaluate the inclusion of exercise as adjunct therapy to replace the prescription of additional drugs in poorly controlled patients.

This study aimed to assess the effects of isotemporal replacement of sitting time (SIT) with standing (STA) on cardiometabolic biomarkers. In this cross-sectional study, male adolescents wore the GT3X+ activity monitor for 7 days to measure the SIT and STA. Moderate-to-vigorous physical activity (MVPA) was estimated by a youth-specific cut-off point. An isotemporal substitution approach was used to examine the effects of replacing different periods of SIT (15, 30, 60, and 120 min) with STA on cardiometabolic biomarkers [total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), non-HDL-c, low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), glucose, insulin, HOMA2-β, HOMA2-S, and HOMA2-IR]. Analysis of covariance (ANCOVA) with a post-hoc Bonferroni test was used to compare the adjusted means between the four subgroups that were clustered according to SIT and STA amount. Adolescents (n = 84; age, 16.7 ± 0.9 years) wore GT3X+ for 15.2 ± 2.3 h, for 6.7 ± 0.6 days. Isotemporal substitution of SIT with STA was associated with TC, non-HDL-c, LDL-c, and TG. ANCOVA results showed a statistically significant difference for TC, non-HDL-c, and LDL-c. These findings showed that for male adolescents, sitting less and standing more may be an effective alternative to reduce cardiometabolic biomarker levels related to lipid metabolism, regardless of MVPA.

Background Type 2 diabetes is now a common and serious global health problem, which, for most countries, has evolved in association with rapid cultural and social changes, ageing populations, increasing urbanisation, dietary changes, reduced physical activity and other unhealthy lifestyle and behavioural patterns. Aims To identify the different approaches to physical training used in the last decade in the management of type 2 diabetes. Methods We searched PubMed and Science Direct for all randomised clinical trials from 1999 to 30 May 2010. Results We selected 17 randomised controlled trials, five studies with aerobic exercise, five with resistance exercise and seven combined exercise studies. Conclusions The use of resistance training for the treatment of type 2 diabetes is becoming more commonly used in the management of type 2 diabetes. The number of studies using resistance exercise has been growing over the last decade, and has actually become as widely used as the popular aerobic exercise. In turn, most of the reviewed studies have used interventions combining resistance and aerobic exercise. An exercise programme for diabetic patients should be seen as a form of treatment. Hence, there were no established guidelines for the duration of the programme, because exercise should become a habitual daily task, and assumed in a new lifestyle for long-term glucose control.