Sedentary time associates detrimentally and physical activity beneficially with metabolic flexibility in adults with metabolic syndrome.

Metabolic flexibility (MetFlex) describes the ability to respond and adapt to changes in metabolic demand and substrate availability. The relationship between physical (in)activity and MetFlex is unclear. This study aimed to determine whether sedentary time, physical activity (PA), and cardiorespiratory fitness associate with MetFlex. Sedentary time, standing, and PA were measured with accelerometers for 4 weeks in 64 sedentary adults with metabolic syndrome [37 women, 27 men; 58.3 (SD 6.8) years]. Fitness (V̇o2max; mL·kg-1·min-1) was measured with graded maximal cycle ergometry. MetFlex was assessed with indirect calorimetry as the change in respiratory exchange ratio (ΔRER) from fasting to insulin stimulation with hyperinsulinemic-euglycemic clamp and from low-intensity to maximal exercise. Carbohydrate (CHOox) and fat oxidation (FATox) were calculated from respiratory gases. High sedentary time associated with higher fasting RER [ß = 0.35 (95% confidence interval: 0.04, 0.67)], impaired insulin-stimulated MetFlex (ΔRER) [ß=-0.41 (-0.72, -0.09)], and lower fasting FATox [ß=-0.36 (-0.67, -0.04)]. Standing associated with lower fasting RER [ß=-0.32 (-0.62, -0.02)]. Higher standing time and steps/day associated with higher fasting FATox [ß = 0.31 (0.01, 0.61), and ß = 0.26 (0.00, 0.53)]. Light-intensity and total PA associated with better insulin-stimulated MetFlex [ß = 0.33 (0.05, 0.61)], and ß = 0.33 (0.05, 0.60)]. Higher V̇o2max associated with higher CHOox during maximal exercise [ß = 0.81 (0.62, 1.00)], as well as during insulin stimulation [ß = 0.43 (0.13, 0.73)]. P values are less than 0.05 for all associations. Sedentary time and PA associate with MetFlex. Reducing sitting and increasing PA of even light intensity might aid in the prevention of metabolic diseases in risk populations through their potential effects on energy metabolism.NEW & NOTEWORTHY High accelerometer-assessed sedentary time associates with metabolic inflexibility measured during hyperinsulinemic-euglycemic clamp in adults with metabolic syndrome, and more light-intensity and total physical activity associate with more metabolic flexibility. Physical activity behaviors may thus play an important role in the regulation of fuel metabolism. This highlights the potential of reduced sedentary time and increased physical activity of any intensity to induce metabolic health benefits and help in disease prevention in risk populations.

Periodic mobile application (eMOM) with self-tracking of glucose and lifestyle improves treatment of diet-controlled gestational diabetes without human guidance: a randomized controlled trial.

BACKGROUND: Digitalization with minimal human resources could support self-management among women with gestational diabetes and improve maternal and neonatal outcomes. OBJECTIVE: This study aimed to investigate if a periodic mobile application (eMOM) with wearable sensors improves maternal and neonatal outcomes among women with diet-controlled gestational diabetes without additional guidance from healthcare personnel. STUDY DESIGN: Women with gestational diabetes were randomly assigned in a 1:1 ratio at 24 to 28 weeks' gestation to the intervention or the control arm. The intervention arm received standard care in combination with use of the periodic eMOM, whereas the control arm received only standard care. The intervention arm used eMOM with a continuous glucose monitor, an activity tracker, and a food diary 1 week/month until delivery. The primary outcome was the change in fasting plasma glucose from baseline to 35 to 37 weeks' gestation. Secondary outcomes included capillary glucose, weight gain, nutrition, physical activity, pregnancy complications, and neonatal outcomes, such as macrosomia. RESULTS: In total, 148 women (76 in the intervention arm, 72 in the control arm; average age, 34.1±4.0 years; body mass index, 27.1±5.0 kg/m2) were randomized. The intervention arm showed a lower mean change in fasting plasma glucose than the control arm (difference, -0.15 mmol/L vs -2.7 mg/mL; P=.022) and lower capillary fasting glucose levels (difference, -0.04 mmol/L vs -0.7 mg/mL; P=.002). The intervention arm also increased their intake of vegetables (difference, 11.8 g/MJ; P=.043), decreased their sedentary behavior (difference, -27.3 min/d; P=.043), and increased light physical activity (difference, 22.8 min/d; P=.009) when compared with the control arm. In addition, gestational weight gain was lower (difference, -1.3 kg; P=.015), and there were less newborns with macrosomia in the intervention arm (difference, -13.1 %; P=.036). Adherence to eMOM was high (daily use >90%), and the usage correlated with lower maternal fasting (P=.0006) and postprandial glucose levels (P=.017), weight gain (P=.028), intake of energy (P=.021) and carbohydrates (P=.003), and longer duration of the daily physical activity (P=.0006). There were no significant between-arm differences in terms of pregnancy complications. CONCLUSION: Self-tracking of lifestyle factors and glucose levels without additional guidance improves self-management and the treatment of gestational diabetes, which also benefits newborns. The results of this study support the use of digital self-management and education tools in maternity care.

Physical activity has decreased in Finnish children and adolescents from 2016 to 2022.

BACKGROUND: Varying trends in children's and adolescents' physical activity (PA) have been reported during the last 10-20 years. Trends in sedentary behavior (SB) have been studied only rarely. The purpose of the present study was to describe population-based trends in accelerometer-measured PA, standing and SB, among Finnish 7-15-year-old children and adolescents, and to evaluate the potential influence of the COVID-19 pandemic on these behaviors. METHOD: A cross-sectional population-based Finnish school-aged physical activity Study (FSPA) measured daily steps, vigorous (VPA), moderate (MPA), moderate-to-vigorous (MVPA), light physical activity (LPA), standing, and SB by an accelerometer for seven consecutive days in 2016, 2018, and 2022 (n = 7.080, 57% girls). The data was analyzed by multivariate regression analysis. RESULTS: In 2016, participants took on average 10.305 steps per day, and spent 0:15 (h: min) in VPA, 1:37 in MPA, 1:52 in MVPA, 3:48 in LPA, 0:55 in standing and 7:52 in SB. From 2016 to 2018, daily steps, MPA, LPA, and standing increased [229 steps (95% Confidence Interval, CI 70-387), 0:03 (CI 0:01 - 0:04), 0:11 (CI 0:09 - 0:14), and 0:07 (CI 0:05 - 0:08), respectively], while VPA and SB decreased [0:01 (CI 0:00-0:02) and 0:20 (CI 0:16 - 0:24), respectively]. From 2018 to 2022, daily PA and standing declined [751 steps (CI 562-939), VPA 0:02 (CI 0:01 - 0:03), MPA 0:09 (CI 0:07 - 0:11), MVPA 0:11 (CI 0:09 - 0:14), LPA 0:08 (CI 0:05 - 0:11), and standing 0:01 (CI 0:01 - 0:03)] while SB increased 0:21 (CI 0:16 - 0:25) indicating potential influence of the pandemic. CONCLUSIONS: Children and adolescents became physically less active from 2016 to 2022. The potential effects of the COVID-19 were seen as declined PA and increased sedentariness from 2018 to 2022.

Elective Cardiac Procedure Patients Have Low Preoperative Cardiorespiratory Fitness.

Preoperative cardiorespiratory fitness may influence the recovery after cardiac procedure. The aim of this study was to investigate the cardiorespiratory fitness of patients scheduled for elective cardiac procedures, using a six-minute walk test, and compare the results with a population-based sample of Finnish adults. Patients (n=234) awaiting percutaneous coronary intervention or coronary angiography, coronary artery bypass grafting, aortic valve replacement or mitral valve surgery performed the six-minute walk test. VO2max was calculated based on the walk test. The patients were compared to a population-based sample of 60-69-year-old Finnish adults from the FinFit2017 study. The mean six-minute walk test distances (meters) and VO2max (ml/kg/min) of the patient groups were: 452±73 and 24.3±6.9 (coronary artery bypass grafting), 499±84 and 27.6±7.2 (aortic valve replacement), 496±85 and 27.4±7.3 (mitral valve surgery), and 519±90 and 27.3±6.9 (percutaneous coronary intervention or coronary angiography). The population-based sample had significantly greater walk test distance (623±81) and VO2max (31.7±6.1) than the four patient groups (all p-values<0.001). All patient groups had lower cardiorespiratory fitness than the reference population of 60-69-year-old Finnish adults. Particularly the coronary artery bypass grafting group had a low cardiorespiratory fitness, and therefore might be prone to complications and challenging rehabilitation after the operation.

Measurement of Sedentary Behavior-The Outcomes of the Angle for Posture Estimation (APE) Method.

Hip-worn accelerometers are commonly used to assess habitual physical activity, but their accuracy in precisely measuring sedentary behavior (SB) is generally considered low. The angle for postural estimation (APE) method has shown promising accuracy in SB measurement. This method relies on the constant nature of Earth's gravity and the assumption that walking posture is typically upright. This study investigated how cardiorespiratory fitness (CRF) and body mass index (BMI) are related to APE output. A total of 3475 participants with adequate accelerometer wear time were categorized into three groups according to CRF or BMI. Participants in low CRF and high BMI groups spent more time in reclining and lying postures (APE ≥ 30°) and less time in sitting and standing postures (APE < 30°) than the other groups. Furthermore, the strongest partial Spearman correlation with CRF (r = 0.284) and BMI (r = -0.320) was observed for APE values typical for standing. The findings underscore the utility of the APE method in studying associations between SB and health outcomes. Importantly, this study emphasizes the necessity of reserving the term "sedentary behavior" for studies wherein the classification of SB is based on both intensity and posture.

Association Between Accelerometer-Measured Physical Activity and Mobility Limitations in Twins.

BACKGROUND: The associations between mobility limitations and device-measured physical activity are sparsely studied. In this study, these associations are studied among community-dwelling older twins. METHODS: This cross-sectional study utilized data gathered in 2014-2016 for the MOBILETWIN study. Participants were twins born in Finland between 1940 and 1944 (774 participants, mean age 73 years). Physical activity was measured with a hip-worn accelerometer. Mobility limitations were assessed with a questionnaire. RESULTS: Individual-level analyses revealed that physical activity was associated with mobility limitations. Participants with severe mobility limitations took 2,637 (SD = 1,747) steps per day, those with some mobility limitations 4,437 (SD = 2,637) steps, and those without mobility limitations 7,074 (SD = 2,931) steps (p < .05). The within-twin pair analyses revealed the same pattern for the 144 dizygotic twin pairs, but no associations were seen for the 117 monozygotic twin pairs. CONCLUSIONS: Accelerometer-measured physical activity and mobility limitations were associated in community-dwelling older adults. Genetic factors may explain some of the variations in physical activity. SIGNIFICANCE: A personalized exercise program to promote increased physical activity should be provided for older adults who report mobility difficulties. Future research is needed to examine causality between physical activity and mobility limitations.

The effects of a 6-month intervention aimed to reduce sedentary time on skeletal muscle insulin sensitivity: a randomized controlled trial.

Sedentary behavior (SB) and physical inactivity associate with impaired insulin sensitivity. We investigated whether an intervention aimed at a 1-h reduction in daily SB during 6 mo would improve insulin sensitivity in the weight-bearing thigh muscles. Forty-four sedentary inactive adults [mean age 58 (SD 7) yr; 43% men] with metabolic syndrome were randomized into intervention and control groups. The individualized behavioral intervention was supported by an interactive accelerometer and a mobile application. SB, measured with hip-worn accelerometers in 6-s intervals throughout the 6-mo intervention, decreased by 51 (95% CI 22-80) min/day and physical activity (PA) increased by 37 (95% CI 18-55) min/day in the intervention group with nonsignificant changes in these outcomes in the control group. Insulin sensitivity in the whole body and in the quadriceps femoris and hamstring muscles, measured with hyperinsulinemic-euglycemic clamp combined with [18F]fluoro-deoxy-glucose PET, did not significantly change during the intervention in either group. However, the changes in hamstring and whole body insulin sensitivity correlated inversely with the change in SB and positively with the changes in moderate-to-vigorous PA and daily steps. In conclusion, these results suggest that the more the participants were able to reduce their SB, the more their individual insulin sensitivity increased in the whole body and in the hamstring muscles but not in quadriceps femoris. However, according to our primary randomized controlled trial results, this kind of behavioral interventions targeted to reduce sedentariness may not be effective in increasing skeletal muscle and whole body insulin sensitivity in people with metabolic syndrome at the population level.NEW & NOTEWORTHY Aiming to reduce daily SB by 1 h/day had no impact on skeletal muscle insulin sensitivity in the weight-bearing thigh muscles. However, successfully reducing SB may increase insulin sensitivity in the postural hamstring muscles. This emphasizes the importance of both reducing SB and increasing moderate-to-vigorous physical activity to improve insulin sensitivity in functionally different muscles of the body and thus induce a more comprehensive change in insulin sensitivity in the whole body.

Effects of reducing sedentary behavior on cardiorespiratory fitness in adults with metabolic syndrome: A 6-month RCT.

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 .

Longitudinal physical activity patterns and the development of cardiometabolic risk factors during adolescence.

PURPOSE: To examine the associations between longitudinal physical activity (PA) patterns and the development of cardiometabolic risk factors from adolescence to young adulthood. METHODS: This cohort study encompassed 250 participants recruited from sports clubs and schools, and examined at mean age 15 and 19. Device-measured moderate-to-vigorous PA was grouped into five patterns (via a data-driven method, using inactivity maintainers as a reference). The outcomes were: glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), total cholesterol, HDL and LDL cholesterol, triglycerides, blood pressure, and body mass index (BMI). Linear growth curve models were applied with adjustment for sex, age, fruit/vegetable consumption, cigarette/snuff use, and change in the device wear-time. RESULTS: Insulin and BMI increased among decreasers from moderate to low PA (ß for insulin 0.23, 95% CI 0.03-0.46; ß for BMI 0.90; CI 0.02-1.78). The concentration of HDL cholesterol decreased (ß -0.18, CI -0.31 to -0.05) and that of glucose increased (ß 0.18, CI 0.02-0.35) among decreasers from high to moderate PA. By contrast, among increasers, blood pressure declined (systolic ß -6.43, CI -12.16 to -0.70; diastolic ß -6.72, CI -11.03 to -2.41). CONCLUSIONS: Already during the transition to young adulthood, changes in PA are associated with changes in cardiometabolic risk factors. Favorable blood pressure changes were found among PA increasers. Unfavorable changes in BMI, insulin, glucose, and HDL cholesterol were found in groups with decreasing PA. The changes were dependent on the baseline PA and the magnitude of the PA decline.

Associations of sedentary time, physical activity, and fitness with muscle glucose uptake in adults with metabolic syndrome.

OBJECTIVE: The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU). METHODS: Sedentary time and physical activity were measured with accelerometers and VO2 max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [18 F]FDG-PET imaging. RESULTS: Sedentary time (ß = -0.374), standing (ß = 0.376), steps (ß = 0.351), and VO2 max (ß = 0.598) were associated with muscle GU when adjusted for sex, age, and accelerometer wear time. Adjustment for body fat-% turned all associations non-significant. CONCLUSION: Body composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness.

Psychosocial and health behavioural characteristics of longitudinal physical activity patterns: a cohort study from adolescence to young adulthood.

BACKGROUND: The decline in physical activity (PA) during adolescence is well-established. However, while some subgroups of adolescents follow the general pattern of decreased activity, others increase or maintain high or low activity. The correlates and determinants of different PA patterns may vary, offering valuable information for targeted health promotion. This study aimed to examine how psychosocial factors, health behaviours, and PA domains are associated with longitudinal PA patterns from adolescence to young adulthood. METHODS: This prospective study encompassed 254 participants measured at mean ages 15 and 19. Device-measured moderate-to-vigorous PA was grouped into five patterns (activity maintainers, inactivity maintainers, decreasers from moderate to low PA, decreasers from high to moderate PA, increasers) via a data-driven method, K-Means for longitudinal data. Multinomial logistic regression was used to analyse the associations between health behaviours, psychosocial factors, PA domains, and different PA patterns. RESULTS: A lack of sports club participation characterised inactivity maintainers throughout adolescence. Difficulties in communicating with one's father at age 15 were associated with higher odds of belonging to inactivity maintainers and to decreasers from moderate to low PA. Lower fruit and vegetable consumption at age 19 was also related to increased odds of belonging to the groups of inactivity maintainers and decreasers from moderate to low PA. Smoking at age 19 was associated with being a decreaser from moderate to low PA. CONCLUSIONS: Diverse factors characterise longitudinal PA patterns over the transition to young adulthood. Sports club participation contributes to maintained PA. Moreover, a father-adolescent relationship that supports open communication may be one determinant for sustained PA during adolescence. A healthier diet and non-smoking as a young adult are associated with more favourable PA development.

Floating Epoch Length Improves the Accuracy of Accelerometry-Based Estimation of Coincident Oxygen Consumption.

Estimation of oxygen consumption (VO2) from accelerometer data is typically based on prediction equations developed in laboratory settings using steadily paced and controlled test activities. These equations may not capture the temporary changes in VO2 occurring in sporadic real-life physical activity. In this study, we introduced a novel floating epoch for accelerometer data analysis and hypothesized that an adaptive epoch length provides a more consistent estimation of VO2 in irregular activity conditions than a 6 s constant epoch. Two different activity tests were conducted: a progressive constant-speed test (CS) performed on a track and a 6 min back-and-forth walk test including accelerations and decelerations (AC/DC) performed as fast as possible. Twenty-nine adults performed the CS test, and sixty-one performed the AC/DC test. The data were collected using hip-worn accelerometers and a portable metabolic gas analyzer. General linear models were employed to create the prediction models for VO2 that were cross-validated using both data sets and epoch types as training and validation sets. The prediction equations based on the CS test or AC/DC test and 6 s epoch had excellent performance (R2 = 89%) for the CS test but poor performance for the AC/DC test (31%). Only the VO2 prediction equation based on the AC/DC test and the floating epoch had good performance (78%) for both tests. The overall accuracy of VO2 prediction is compromised with the constant length epoch, whereas the prediction model based on irregular acceleration data analyzed with a floating epoch provided consistent performance for both activities.

Performance of Different Accelerometry-Based Metrics to Estimate Oxygen Consumption during Track and Treadmill Locomotion over a Wide Intensity Range.

Accelerometer data can be used to estimate incident oxygen consumption (VO2) during physical activity. Relationships between the accelerometer metrics and VO2 are typically determined using specific walking or running protocols on a track or treadmill. In this study, we compared the predictive performance of three different metrics based on the mean amplitude deviation (MAD) of the raw three-dimensional acceleration signal during maximal tests performed on a track or treadmill. A total of 53 healthy adult volunteers participated in the study, 29 performed the track test and 24 the treadmill test. During the tests, the data were collected using hip-worn triaxial accelerometers and metabolic gas analyzers. Data from both tests were pooled for primary statistical analysis. For typical walking speeds at VO2 less than 25 mL/kg/min, accelerometer metrics accounted for 71-86% of the variation in VO2. For typical running speeds starting from VO2 of 25 mL/kg/min up to over 60 mL/kg/min, 32-69% of the variation in VO2 could be explained, while the test type had an independent effect on the results, except for the conventional MAD metrics. The MAD metric is the best predictor of VO2 during walking, but the poorest during running. Depending on the intensity of locomotion, the choice of proper accelerometer metrics and test type may affect the validity of the prediction of incident VO2.

How adherence to the updated physical activity guidelines should be assessed with accelerometer?

BACKGROUND: The aerobic part of the recently updated physical activity (PA) guidelines for adults recommends at least 150 min of moderate or at least 75 of vigorous-intensity PA or an equivalent combination of both. PA can be accumulated of any bout duration. On an absolute scale, moderate-intensity threshold is 3 metabolic equivalents (METs) and vigorous 6 METs. On a scale relative to individual's personal capacity, moderate-intensity threshold is 40% and vigorous 60% of the oxygen uptake reserve. In this study, the adherence to the new guidelines was evaluated using both absolute and relative thresholds. METHODS: Totally, 1645 adults aged 20-64 years, participated in this population-based study and their cardiorespiratory fitness (CRF) was estimated with 6-min walking test. The participants with estimated maximal oxygen uptake <7.9 MET were categorized as low CRF group and the others as adequate CRF group. The participants were instructed to wear a triaxial hip-worn accelerometer for 1 week and their adherence to PA guidelines was assessed from the accelerometer data. RESULTS: The adequate CRF group had higher adherence to PA guidelines with the absolute thresholds, but the use of relative thresholds inverted the results. The adherence varied from 20% to 99% in the total sample depending on the analysis parameters of accelerometer data. CONCLUSIONS: The absolute thresholds provide a more appropriate basis to assess the adherence to PA guidelines in population-based samples and interventions. The use of individually determined relative thresholds may be more useful for individual exercise prescriptions in PA counseling.

Physical activity from adolescence to young adulthood: patterns of change, and their associations with activity domains and sedentary time.

BACKGROUND: Longitudinal studies demonstrate an average decline in physical activity (PA) from adolescence to young adulthood. However, while some subgroups of adolescents decrease activity, others increase or maintain high or low activity. Activity domains may differ between subgroups (exhibiting different PA patterns), and they offer valuable information for targeted health promotion. Hence, the aim of this study was to identify PA patterns from adolescence to young adulthood; also to explore the associations of (i) changes in PA domains and in sedentary time, (ii) sociodemographic factors, and (iii) self-rated health with diverging PA patterns. METHODS: The observational cohort study data encompassed 254 adolescents at age 15 and age 19. K-means cluster analysis for longitudinal data was performed to identify participant clusters (patterns) based on their accelerometry-measured moderate-to-vigorous PA (MVPA). Logistic regressions were applied in further analysis. RESULTS: Five PA patterns were identified: inactivity maintainers (n = 71), activity maintainers (n = 70), decreasers from moderate (to low) PA (n = 61), decreasers from high (to moderate) PA (n = 32), and increasers (n = 20). At age 15, participation in sports clubs (SC, 41-97%) and active commuting (AC, 47-75%) was common in all the patterns. By age 19, clear dropout from these activities was prevalent (SC participation mean 32%, AC 31-63%). Inactivity maintainers reported the lowest amount of weekly school physical education. Dropout from SC - in contrast to non-participation in SC - was associated with higher odds of being a decreaser from high PA, and with lower odds of being an inactivity maintainer. Maintained SC participation was associated with higher odds of belonging to the decreasers from high PA, and to the combined group of activity maintainers and increasers; also with lower odds of being an inactivity maintainer. Maintenance/adoption of AC was associated with decreased odds of being an inactivity maintainer. Self-reported health at age 19 was associated with the patterns of maintained activity and inactivity. CONCLUSIONS: PA patterns diverge over the transition to adulthood. Changes in SC participation and AC show different associations with diverging PA patterns. Hence, tailored PA promotion is recommended.

Higher number of steps and breaks during sedentary behaviour are associated with better lipid profiles.

BACKGROUND: Physical activity (PA) is known to be associated with lipid profiles and the risk of both cardiovascular diseases and cancer. The aim of this study was to evaluate the association of objectively measured PA, sedentary behaviour (SB), amount of breaks during SB and number of daily steps with serum lipids in a healthy, Finnish, middle-aged, female population. METHODS: The participants (571) were recruited at mammography screening, target group was women aged 50-60 years. A measurement of PA was done with accelerometer, blood lipid profile was assessed, and questionnaires of participants characteristics were sent to participants. RESULTS: The participants with the highest number of daily breaks during SB (≥ 41) had the highest mean concentration of HDL-cholesterol (high density lipoprotein cholesterol, HDL-c) (1.9 mmol/l, standard deviation (SD) 0.4) and the lowest mean concentration of triglycerides (1.0 mmol/l, SD 0.5). HDL-c level was 0.16 mmol/l higher (p < 0.001) in the group with 28-40.9 breaks/day and 0.25 mmol/l higher (p < 0.001) among participants with ≥41 breaks/day than in the group with the fewest breaks during SB (< 28). Those with the most daily steps (≥ 9100) had the highest mean HDL-c level (1.9 mmol/l). HDL-c level was 0.16 mmol/l higher (p < 0.001) among the participants with 5600-9099 steps/day and 0.26 mmol/l higher (p < 0.001) among participants with ≥9100 steps/day than those with the fewest steps (< 5600). The number of daily steps was inversely associated with the triglyceride concentration. From wake-time, participants spent 60% in SB, 18% standing, 14% in light PA, and 9% in moderate-to-vigorous PA (MVPA). PA was associated with serum total cholesterol (TC), HDL-c and triglyceride levels. The mean HDL-c level was the highest in the lowest quartile of SB and in the highest quartile of MVPA. CONCLUSIONS: To our knowledge, this is the first study showing a high number of objectively measured breaks during SB is associated with a favourable effect on the level of serum lipids, which may later translate into cardiovascular health among middle-aged women. TRIAL REGISTRATION: This study was registered and approved by the Regional Ethics Committee of Tampere University Hospital in Finland (approval code R15137 ).

Intensity Paradox-Low-Fit People Are Physically Most Active in Terms of Their Fitness.

Depending on their cardiorespiratory fitness (CRF), people may perceive the exertion of incident physical activity (PA) differently. Therefore, the use of relative intensity thresholds based on individual fitness have been proposed to evaluate the accumulation of PA at different intensity levels. A subsample of the FinFit2017-study, 1952 adults (803 men and 1149 women) aged 20-69 years, participated in this study. Their maximal oxygen uptake (VO2max) was predicted with a 6 min walk test, and they were instructed to wear a triaxial hip-worn accelerometer for one week. The participants were divided into CRF tertiles by five age groups and sex. Raw acceleration data were analyzed with the mean amplitude deviation method in 6 s epochs. Additionally, the data were smoothed with 1 min and 6 min exponential moving averages. The absolute intensity threshold for moderate activity was 3.0 metabolic equivalent (MET) and for vigorous 6.0 MET. Correspondingly, the relative thresholds were 40% and 60% of the oxygen uptake reserve. Participants in the lowest CRF tertile were the most active with relative thresholds, and participants in the highest CRF tertile were the most active with absolute thresholds. High-fit people easily reached the absolute thresholds, while people in the lowest CRF tertile had to utilize most of their aerobic capacity on a daily basis simply to keep up with their daily chores or peers.

Motives for physical activity in older men and women: A twin study using accelerometer-measured physical activity.

Motives for physical activity may vary considerably by age, sex, and the level of physical activity. We aimed to examine motives for physical activity in older men and women with different physical activity levels as well as whether genetic and/or environmental factors explain those motives. Finnish twins (mean age 72.9 years, 262 full twin pairs) self-reported their motives for physical activity. Time spent on moderate-to-vigorous physical activity was monitored using a hip-worn accelerometer. Comparisons between the different physical activity groups of older twins (n = 764-791/motive dimension) were analyzed using the Wald test, and effect sizes were calculated as Cohen's d. Quantitative genetic modeling was used to estimate genetic and environmental contributions. For both sexes, the most frequently reported motives for physical activity were physical fitness, health maintenance, and psychological well-being. Conforming to others' expectations was more important for men than for women (P < .001, Cohen's d = 0.38), while appearance (P = .001 Cohen's d = -0.24) and psychological well-being (P = .02, Cohen's d = -0.17) were highlighted by women. Most of the motive dimensions differed significantly between the physically active and inactive individuals. It was estimated that 5%-42% of the variation in motives was contributed by genetic factors and 58%-95% by environmental factors. The result that environmental factors contribute in a great deal to motives indicates that interventions to motivate physically inactive older individuals to be physically active can be successful. However, personalized interventions are needed because sex and the level of physical activity were found to be associated with older individuals' motives for physical activity.

Frequent sit-to-stand transitions and several short standing periods measured by hip-worn accelerometer are associated with smaller waist circumference among adults.

This cross-sectional study analysed the association of sedentary behaviour (SB) and standing with waist circumference. Finnish adults aged 30-75 years from a sub-sample of population-based Health 2011 Study used a hip-worn tri-axial accelerometer (Hookie AM20, Traxmeet, Ltd, Espoo, Finland) for seven days. Those 1405 participants (57% women) who used accelerometer at least four days, minimum of 10 hours/day, were included. SB and standing were analysed in 6s epochs using validated algorithm. Daily total time, daily number and accumulated time from bouts (30s-5min,30s-10min,30s-15min,30s 30min,>5min,>10min,>15min, >30min) as well as daily number of sit-to-stand transitions were determined. Waist circumference (cm) was measured in standardized way. Participants' mean age was 52 years (SD 12.2). Mean waist circumference was 97cm (SD 12.3) in men and 87cm (SD 12.7) in women. According to multivariable stepwise linear regression analysis, sit-to-stand transitions [standardised regression coefficient (ß)= -0.14, 95%CI -0.20 to -0.09], standing bouts of 30s-5min (ß= -0.21, 95%CI -0.26 to -0.15) and number of 30s-30min SB bouts (ß=0.12, 95%CI 0.06 to 0.17) were most strongly associated with waist circumference. Besides assessing total SB time, future studies should assess also different bout lengths of SB and sit-to-stand transitions and standing times should be assessed separately.

Physical Activity and Body Composition in Children and Their Mothers According to Mother's Gestational Diabetes Risk: A Seven-Year Follow-Up Study.

Background and Objectives: There is lack of knowledge on whether mothers' gestational diabetes (GDM) risk is related to their physical activity (PA) or their children's PA and body composition. We aimed to examine the difference in (1) change in self-reported PA from pre-pregnancy to seven-year follow-up and (2) accelerometer-based PA at seven years after delivery between the mothers having GDM risk (GDMRyes-mothers) and not having GDM risk (GDMRno-mothers). Furthermore, we examined the difference in children's PA and/or body composition at six years of age according to their mothers' GDM risk. Materials and Methods: The study included 199 Finnish women. GDM risk factors were screened at the beginning of pregnancy, and the women were classified as GDMRyes-mothers if they had at least one GDM risk factor (body mass index ≥25 kg/m2; age ≥40 years; family history of diabetes; GDM, signs of glucose intolerance, or newborn's macrosomia (≥4500 g) in earlier pregnancy) or as GDMRno-mothers if they had no risk factors. Mothers' PA was assessed by self-reporting at 8-12 gestational weeks concerning pre-pregnancy PA and at a follow-up seven years after the delivery. Moreover, mothers' and their children's PA was measured using a triaxial Hookie AM20-accelerometer at seven years after delivery. Children's body composition was assessed using a TANITA bioelectrical impedance device. Adjusted linear regression analyses were applied. Results: GDMRno-mothers increased their self-reported PA more than GDMRyes-mothers from pre-pregnancy to the seven-year follow-up. Concerning women's measured PA as well as children's PA and body composition at seven years after delivery, the differences were non-significant between GDMRyes-mothers and GDMRno-mothers. However, of the GDM risk factors, mothers' pre-pregnancy body mass index was positively related to unhealthier body composition in boys at six years of age. Conclusion: Health promotion should be targeted at women with GDM risk factors, in particular overweight women, in enhancing women's PA in the long term and their children's healthy body composition.