This systematic review and meta-analysis aimed to determine the magnitude of the effect of combined exercise training on glucose metabolism markers, adipokines, and inflammatory cytokines in non-diabetic sedentary adults. PubMed, Web of Science, Scopus, Cochrane Library electronic databases and reference lists of included studies were explored for randomized controlled trials (RCTs) that included physically inactive adults and provided combined training interventions (aerobic plus resistance exercise). Effects on fasting glucose and insulin, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), HbA1c, adiponectin, leptin, IL-6, TNF-α, and C-reactive protein (CRP) in exercise vs control groups were analyzed using random effects meta-analysis. The Cochrane Risk of Bias Tool for Randomized Trials 2.0 (RoB 2) was used to assess the risk of bias. A total of 24 RCTs were included in the quantitative analysis. Combined exercise training significantly decrease fasting glucose (standardized mean difference, SMD: − 0.474, 95% CI [− 0.829, − 0.120], p = 0.009, 35 study arms), fasting insulin (SMD: − 1.024, 95% CI [− 1.502, − 0.545], p < 0.001, 27 study arms), HOMA-IR (SMD: − 0.946, 95% CI [− 1.450, − 0.442], p < 0.001, 23 study arms), TNF-α (SMD: − 0.972, 95% CI [− 1.361, − 0.582], p < 0.001, 10 study arms), and CRP (SMD: − 0.507, 95% CI [− 0.818, − 0.196], p = 0.001, 14 study arms). No significant effects were observed for HbA1c, adiponectin, leptin, and IL-6 levels. Random effects meta-regression models by age, sex, and intervention length were not able to explain any of the variation in the effect size of HOMA-IR. Findings from this systematic review and meta-analysis suggest that combined exercise training improves some glucose metabolism markers and inflammatory parameters in sedentary adults without diabetes.

Background: Sedentary behavior has been considered an independent risk factor to health. The aim of this systematic review and meta-analysis was to examine associations between objectively measured sedentary time and physical fitness components in healthy adults. Methods: Four electronic databases (Web of Science, Scopus, Pubmed and Sport Discus) were searched (up to 20 September 2020) to retrieve studies on healthy adults which used observational, cohort and cross-sectional designs. Studies were included if sedentary time was measured objectively and examined associations with the health- or skill-related attributes of physical fitness (e.g., muscular strength, cardiorespiratory fitness, balance). After applying additional search criteria, 21 papers (11,101 participants) were selected from an initial pool of 5192 identified papers. Results: Significant negative associations were found between total sedentary time with cardiorespiratory fitness (r = −0.164, 95%CI: −0.240, −0.086, p < 0.001), muscular strength (r = −0.147, 95%CI: −0.266, −0.024, p = 0.020) and balance (r = −0.133, 95%CI: −0.255, −0.006, p = 0.040). Conclusions: The evidence found suggests that sedentary time can be associated with poor physical fitness in adults (i.e., muscular strength, cardiorespiratory fitness and balance), so strategies should be created to encourage behavioral changes.

This study aimed to analyze the effects of a combined training (CT) program performed during the first national lockdown due to the COVID-19 pandemic on body composition, metabolic profile, quality of life and stress in sedentary workers, and examines whether changes in the metabolic profile are associated with changes in health-related outcomes which are modifiable by exercise. We evaluated 31 sedentary workers (48.26 ± 7.89 years old). Participants were randomly assigned to a CT group (i.e., performed 16 weeks of exercise) or to a non-exercise control group. The CT program consisted of 16-week of resistance and aerobic exercise. Body composition, glycemic and lipidic profiles, cardiorespiratory fitness (CRF), health-related quality of life and stress levels were assessed pre- and post-intervention. After the intervention period, the CT group demonstrated significantly lower waist and hip circumference (p < 0.05) values than the control group. The control group significantly increased the fasting glucose and HOMA-IR after 16 weeks follow-up (+4.74 mg/dL, p = 0.029; and +0.41 units, p = 0.010, respectively), whiles no significant changes were observed in the CT group in the same parameters (+3.33 mg/dL, p = 0.176; and +0.04 units, p = 0.628, respectively). No changes were observed in the lipid profile for either group (p > 0.05). A significant positive relationship was detected between the change in BMI with the changes in insulin and HOMA-IR (r = 0.643, p = 0.024; and r = 0.605, p = 0.037, respectively). In addition, the changes in CRF were negatively associated with the changes in total cholesterol (r = −0.578, p = 0.049). We observed differences between groups on perceived stress levels and physical, psychological, and environmental domains of quality of life, with the CT group showing better results. Moreover, the CT group improved perceived life satisfaction (+3.17 points, p = 0.038). The findings of the present study suggest that the participants who remained physically active during the first pandemic-related lockdown were able to mitigate the deleterious effects associated with a sedentary lifestyle.

Purpose: We investigated the effects of a 16-wk combined exercise training on body composition, and metabolic and inflammatory markers in sedentary middle-aged workers. We also assessed whether alterations in metabolic markers were associated with changes in health-related outcomes. Methods: This randomized controlled trial involved 46 participants randomly allocated into control and exercise groups. The exercise group performed 16-wk combined aerobic and resistance training for 75 min per session, 3 times a week. Fasting blood samples were collected at baseline and after 16-wk intervention to determine lipid profile, and metabolic and inflammatory markers as primary outcomes. Results: A total of 36 participants completed the intervention (53.70 ± 6.92 yr old; n = 18 in each group). Waist circumference (interaction effect: F = 7.423, P = 0.002), fat mass (interaction effect: F = 5.070, P = 0.011), and muscle mass (interaction effect: F = 5.420, P = 0.007) were improved in the exercise group compared with the control group. Fasting glucose increased after the 16-wk follow-up (time effect: F = 73.253, P < 0.001), without an intergroup difference. Insulin levels were greater in the control compared with exercise group (group effect: F = 6.509, P = 0.015). The control group tended to increase the homeostatic model assessment of insulin resistance index (interaction effect: F = 3.493, P = 0.070) and to decrease the QUICKI index (interaction effect: F = 3.364, P = 0.075) to a greater extent compared with the exercise group. Exercise group reduced leptin (interaction effect: F = 11.175, P = 0.002) and adiponectin (interaction effect: F = 4.437, P = 0.043) concentrations in a greater magnitude than the control group. Interleukin (IL)-6 (time effect: F = 17.767, P < 0.001) and tumor necrosis factor α (time effect: F = 9.781, P = 0.004) concentrations decreased after the intervention, without an intergroup difference. IL-17A levels increased in the control compared with exercise group (interaction effect: F = 5.010, P = 0.033). Effects on adiponectin, IL-6, and IL-17A levels seem to depend on baseline body mass index, age, and sex. Percentage changes in leptin correlated positively with changes in homeostatic model assessment of insulin resistance index in the exercise (r = 0.565, P = 0.015) and control (r = 0.670, P = 0.002) groups. Conclusions: A combined training program can be an effective strategy to improve body composition and inflammatory markers and prevent marked reductions in insulin sensitivity among middle-aged workers.