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The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU).Sedentary time and physical activity were measured with accelerometers and VOSedentary time (β = -0.374), standing (β = 0.376), steps (β = 0.351), and VOBody composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness.

Objectives: To investigate if reducing sedentary behavior improves cardiometabolic biomarkers in adults with metabolic syndrome. Design: Randomized controlled trial. Methods: Sixty-four sedentary middle-aged adults with metabolic syndrome were randomized into intervention (INT; n = 33) and control (CON; n = 31) groups. INT was guided to limit sedentary behavior by 1 h/day through increased standing and light-intensity physical activity. CON was instructed to maintain usual habits. Sedentary behavior, breaks in sedentary behavior, standing, and physical activity were measured with hip-worn accelerometers for three months. Fasting blood sampling and measurements of anthropometrics, body composition, and blood pressure were performed at baseline and at three months. Linear mixed models were used for statistical analyses. Results: INT reduced sedentary behavior by 50 (95% CI: 24, 73) min/day by increasing light-intensity and moderate-to-vigorous physical activity (19 [8, 30] and 24 [14, 34] min/day, respectively). Standing increased also, but non-significantly (6 [−11, 23] min/day). CON maintained baseline activity levels. Significant intervention effects favoring INT occurred in fasting insulin (INT: 83.4 [68.7, 101.2] vs. CON: 102.0 [83.3, 125.0] pmol/l at three months), insulin resistance (HOMA-IR; 3.2 [2.6, 3.9] vs. 4.0 [3.2, 4.9]), HbA1c (37 [36, 38] vs. 38 [37, 39] mmol/mol), and liver enzyme alanine aminotransferase (28 [24, 33] vs. 33 [28, 38] U/l). Conclusions: Reducing sedentary behavior by 50 min/day and increasing light-intensity and moderate-to-vigorous activity showed benefits in several cardiometabolic biomarkers in adults with metabolic syndrome. Replacing some of the daily sedentary behavior with light-intensity and moderate-to-vigorous physical activity may help in cardiometabolic disease prevention in risk populations. publishedVersion

Purpose This study aimed to investigate whether a reduction in daily sedentary behavior (SB) improves insulin sensitivity in adults with metabolic syndrome in 6 months, without adding intentional exercise training. Methods Sixty-four sedentary inactive middle-age adults with overweight and metabolic syndrome (mean (SD) age, 58 (7) yr; mean (SD) body mass index, 31.6 (4.3) kg·m-2; 27 men) were randomized into intervention and control groups. The 6-month individualized behavioral intervention supported by an interactive accelerometer and a mobile application aimed at reducing daily SB by 1 h compared with baseline. Insulin sensitivity by hyperinsulinemic euglycemic clamp, body composition by air displacement plethysmography, and fasting blood samples were analyzed before and after the intervention. SB and physical activity were measured with hip-worn accelerometers throughout the intervention. Results SB decreased by 40 (95% confidence interval, 17-65) min·d-1, and moderate-to-vigorous physical activity increased by 20 (95% confidence interval, 11-28) min·d-1 on average in the intervention group with no significant changes in these outcomes in the control group. After 6 months, fasting plasma insulin decreased (1 mU·L-1) in the intervention group compared with the control group (time-group, P = 0.0081), but insulin sensitivity did not change in either group. The changes in body mass or adiposity did not differ between groups. Among all participants, the changes in SB and body mass correlated inversely with the change in insulin sensitivity (r = -0.31, -0.44; P = 0.025, 0.0005, respectively). Conclusions An intervention aimed at reducing daily SB resulted in slightly decreased fasting insulin, but had no effects on insulin sensitivity or body adiposity. However, as the change in insulin sensitivity associated with the changes in SB and body mass, multifaceted interventions targeting to weight loss are likely to be beneficial in improving whole-body insulin sensitivity. publishedVersion

Introduction: Poor cardiorespiratory fitness (CRF) is associated with adverse health outcomes. Previous observational and cross-sectional studies have suggested that reducing sedentary behavior (SB) might improve CRF. Therefore, we investigated the effects of a 6-month intervention of reducing SB on CRF in 64 sedentary inactive adults with metabolic syndrome in a non-blind randomized controlled trial. Materials and Methods: In the intervention group (INT, n = 33), the aim was to reduce SB by 1 h/day for 6 months without increasing exercise training. Control group (CON, n = 31) was instructed to maintain their habitual SB and physical activity. Maximal oxygen uptake (VO2max) was measured by maximal graded bicycle ergometer test with respiratory gas measurements. Physical activity and SB were measured during the whole intervention using accelerometers. Results: Reduction in SB did not improve VO2max statistically significantly (group × time p > 0.05). Maximal absolute power output (Wmax) did not improve significantly but increased in INT compared to CON when scaled to fat free mass (FFM) (at 6 months INT 1.54 [95% CI: 1.41, 1.67] vs. CON 1.45 [1.32, 1.59] Wmax/kgFFM, p = 0.036). Finally, the changes in daily step count correlated positively with the changes in VO2max scaled to body mass and FFM (r = 0.31 and 0.30, respectively, p < 0.05). Discussion: Reducing SB without adding exercise training does not seem to improve VO2max in adults with metabolic syndrome. However, succeeding in increasing daily step count may increase VO2max. publishedVersion

Objectives The association between the subjective experience of pain-related disability (PRD) and device-measured physical activity (PA) and sedentary behavior (SB) in overweight and obese adults is not well known. The aim of this study was to investigate the associations of pain markers with accelerometer-measured SB duration and different intensities of PA among physically inactive middle-aged adults with overweight or obesity. Methods This cross-sectional analysis included 72 subjects (27 men) with mean age of 57.9 (SD 6.7) years and mean BMI of 31.6 (SD 4.1) kg/m2. SB and standing time (ST), breaks in sedentary time, light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) were measured for four consecutive weeks (mean 25 days, SD 4) with a hip-worn triaxial accelerometer. Headache, musculoskeletal pain, back pain, and PRD were assessed by visual analog scales (VAS) and using the Oswestry disability index (ODI). RAND-36 questionnaire was applied to assess health-related quality of life. The associations were studied by linear models. Results ST was positively and SB proportion was negatively associated with PRD when adjusted for age, sex, BMI, accelerometry duration, MVPA, pain medication use, and general health perceptions assessed by RAND-36. No associations were found between ST and back pain. SB or different PA intensities were not associated with pain experience at specific sites. Conclusions Longer daily ST, but not LPA or MVPA is associated with higher level of PRD. Correspondingly, higher proportion of SB is associated with lower level of PRD. This suggests that individuals with PRD prefer to stand, possibly to cope with pain. These results may highlight the importance of habitual standing behaviors in coping with experienced PRD in adults with overweight or obesity.

Background Cardiorespiratory fitness (CRF) has been inversely associated with insulin resistance and clustering of cardiometabolic risk factors among overweight and obese individuals. However, most previous studies have scaled CRF by body mass (BM) possibly inflating the association between CRF and cardiometabolic health. We investigated the associations of peak oxygen uptake (V O2peak) and peak power output (Wpeak) scaled either by BM-1, fat free mass (FFM-1), or by allometric methods with individual cardiometabolic risk factors and clustering of cardiometabolic risk factors in 55 overweight or obese adults with metabolic syndrome. Methods V O2peak and Wpeak were assessed by a maximal cycle ergometer exercise test. FFM was measured by air displacement plethysmograph and glucose, insulin, HbA1c, triglycerides, and total, LDL, and HDL cholesterol from fasting blood samples. HOMA-IR and metabolic syndrome score (MetS) were computed. Results V O2peak and Wpeak scaled by BM-1 were inversely associated with insulin (β=-0.404 to -0.372, 95% CI=-0.704 to -0.048), HOMA-IR (β=-0.442 to -0.440, 95% CI=-0.762 to -0.117), and MetS (β=-0.474 to -0.463, 95% CI's=-0.798 to -0.127). Other measures of CRF were not associated with cardiometabolic risk factors. Conclusions Our results suggest that using BM-1 as a scaling factor confounds the associations between CRF and cardiometabolic risk in overweight/obese adults with the metabolic syndrome.

Background: Physical activity (PA) is a determinant of insulin sensitivity. It is more unclear how sedentary behavior (SB) and patterns of SB associate with insulin sensitivity. Purpose: To determine how SB, breaks in sitting, standing, PA, and fitness are associated with insulin sensitivity in adults with metabolic syndrome. Methods: Sixty-four sedentary adults with metabolic syndrome (mean age 58 years; 37 women) were included. SB, breaks in sitting, standing, and PA were measured for four weeks with accelerometers. VO2max was measured with maximal cycle ergometry. Insulin sensitivity was determined by hyperinsulinaemic-euglycaemic clamp (M-value) and fasting blood sampling (HOMA-IR, insulin). Multivariable regression was used for analyses. Results: Sedentary time, standing, steps, and VO2max were associated with M-value, HOMA-IR, and insulin, while breaks in sitting associated only with M-value. When adjusted for body fat %, only standing remained significantly associated with HOMA-IR and insulin, and significance was maintained even when further adjusted for PA, SB, and fitness (all p-values, The Health & Fitness Journal of Canada, Vol. 14 No. 3 (2021): Proceedings from the 8th International Society for Physical Activity and Health Congress

Background: This study examined whether hemoglobin (Hb) and white blood cell count (WBC) associate with body adiposity and other cardiometabolic risk factors, as well as accelerometer-measured sedentary behavior (SB) and physical activity (PA), when adjusted for body mass index (BMI). Methods: The cross-sectional analysis included 144 participants (42 men) with a mean age of 57.0 years and a mean BMI of 31.7 kg/m2. SB and standing time, breaks in sedentary time and PA were measured during four consecutive weeks with hip-worn accelerometers. A fasting blood sample was collected from each participant during the 4-week measurement period and analyzed using Sysmex XN and Cobas 8000 c702 analyzers. Associations of WBC, Hb and other red blood cell markers with cardiometabolic risk factors and physical activity were examined by Pearson’s partial correlation coefficient test and with linear mixed regression models. Results: In sex- and age-adjusted correlation analyses both BMI and waist circumference correlated positively with Hb, WBC, red blood cell count (RBC), and hematocrit. Hb was also positively correlated with systolic blood pressure, insulin resistance scores, liver enzymes, LDL, and triglyceride levels. Sedentary time correlated positively with WBC, whereas standing time correlated negatively with WBC. Lying time correlated positively with WBC, RBC, hematocrit, and Hb. Regarding SB and PA measures, only the association between lying time and RBC remained significant after adjustment for the BMI. Conclusion: We conclude that body adiposity, rather than components of SB or PA, associates with Hb levels and WBC, which cluster with general metabolic derangement.