Comparison of hourly walking and alternating walking-resistance breaks versus prolonged sitting on 26-h glucose responses in sedentary adults: a randomized crossover trial.

PURPOSE: To explore the impact of energy expenditure (EE) on glycemic responses when prolonged sitting is interrupted by three regular activity bouts. METHODS: Fourteenhealthy, sedentary, inactive adults (8 women; age 23.7±2.9 y; BMI, 22.2±2.4 kg/m2; VO2 max, 38.5±5.2ml·kg-1·min) completed four 26 h interventions in randomized order, including 22.5 h in an EE-testing calorimeter chamber. The four 9 h intervention periods were as follows: uninterrupted sitting (SIT); 30 min sitting/3 min brisk treadmill walk (60% VO2max, WALK3); 45 min sitting/5 min brisk treadmill walk (WALK5); or 60 min sitting/8 min brisk treadmill walk (WALK8). Meals and meal times were standardized across the trials for all participants. After adjustment for age, sex, percent of body fat, relative VO2max, treatment order, and corresponding baseline interstitial glucose concentrations, the relationship between EE and the incremental area under the curve (iAUC) for interstitial glucose was examined during the whole 26 h observation period and each segmentation period (intervention period, evening period, and sleep period). The interstitial glucose was obtained via continuous glucose monitoring. Random effects mixed model analyses were performed and data were represented as unstandardized coefficients with 95% confidence intervals. RESULTS: Model parameter estimates revealed that EE was negatively associated with glucose iAUC during the intervention period (β= -1.87 mmol·h·L-1·MJ-1[-3.68 - -0.05], P=0.04) and positively associated with glucose iAUC during the 2 h post-dinner period immediately following the intervention period (β=0.64 mmol·h·L-1·MJ-1[0.27 - 1.00],P=0.001). There was no significant association between EE and glucose iAUC during the entire 26 h observation or the other segmentation periods. The 2 h post-dinner iAUC was higher in men than in women (mean difference: 0.74 mmol·hL-1[0.16 - 1.33], P=0.01). CONCLUSIONS:Higher EE after the interruption of sitting time was associated with lower interstitial glucose responses during the intervention period in healthy, sedentary adults, but the opposite was true in the 2 h postprandial period immediately following the intervention period.

Breaking up periods of prolonged sitting can negate harmful metabolic effects but the influence on appetite and gut hormones is not understood and is investigated in this study. Thirteen sedentary (7 female) participants undertook three 5-h trials in random order: (i) uninterrupted sitting (SIT), (ii) seated with 2-min bouts of light-intensity walking every 20 min (SIT + LA), and (iii) seated with 2-min bouts of moderate-intensity walking every 20 min (SIT + MA). A standardised test drink was provided at the start of each trial and an ad libitum pasta test meal provided at the end of each trial. Subjective appetite ratings and plasma acylated ghrelin, peptide YY, insulin, and glucose were measured at regular intervals. Area under the curve (AUC) was calculated for each variable. AUC values for appetite and gut hormone concentrations were unaffected in the activity breaks conditions compared with uninterrupted sitting (linear mixed modelling: p > 0.05). Glucose AUC was lower in SIT + MA than in SIT + LA (p = 0.004) and SIT (p = 0.055). There was no difference in absolute ad libitum energy intake between conditions (p > 0.05); however, relative energy intake was lower in SIT + LA (39%; p = 0.011) and SIT + MA (120%; p < 0.001) than in SIT. In conclusion, breaking up prolonged sitting does not alter appetite and gut hormone responses to a meal over a 5-h period. Increased energy expenditure from activity breaks could promote an energy deficit that is not compensated for in a subsequent meal.

PURPOSE: To examine whether interrupting prolonged sitting with brief bouts of walking only or combined with simple resistance activity improve glucose levels in healthy, sedentary, young adults. METHODS: This study included 16 healthy, sedentary adults (9 women; 23.7±2.3 y; BMI 20.8±4.1 kg/m2; VO2max 39.1±5.3 ml·kg-1·min-1) who completed three 26-h laboratory conditions, including 22.5 h in a whole-room calorimeter, separated by 5-14 day washout period. The same procedures were performed in each of the three conditions except for the following 9-h activity period: uninterrupted sitting time (SIT); sitting with 8 min intermittent, brisk (60% VO2max) walking bouts (WALK; 7 bouts for a total of 56 min); or alternating 8-min brisk walks and simple resistance activities (RESIST; 3 bouts of walking and 4 bouts of resistance for a total of 56 min). Continuous glucose monitoring (CGM) was performed for 26 h. Standardized meals were consumed during each condition. The incremental areas under the curve (iAUC) for glucose during the entire observation period and the three segmentation periods (activity, evening, and sleep periods) were compared between conditions after adjustment for standard covariates (e.g., age, sex, et al.) and additional adjustment for energy expenditure (EE). RESULTS: Compared with SIT, RESIST reduced 26-iAUC for CGM by 3.04 mmol·L-1·h [95%CI 0.94-6.33] (p = 0.046). Compared with SIT, WALK and RESIST reduced the CGM iAUC by 3.80 mmol·L-1·h [0.19-7.40] (p = 0.036) and 7.37 mmol·L-1·h [4.08-10.66] (p <0.001) during the 9 h activity period, respectively. The iAUC was lowered by 3.57 mmol·L-1·h [0.06-7.08] (p = 0.045) in RESIST compared to WALK. Upon adjusting for EE, the only effect that remained was the comparison between RESIST and SIT during the activity period. During the evening period, WALK increased the CGM iAUC by 1.91 mmol·L-1·h [0.29-3.54] (p = 0.019) when compared to SIT, this effect was lost after adjustment for EE. CONCLUSIONS: Interrupting 9 h of prolonged sitting time with either WALK or RESIST reduced acute glucose responses in healthy, sedentary adults. This effect was more pronounced in RESIST than WALK and was only maintained during the 26-h period in RESIST. Supported by Shanghai Science and Technology Committee (NO. 16080503300)

Prolonged sitting is increasingly recognized as a ubiquitous cardiometabolic risk factor, possibly distinct from lack of physical exercise. We examined whether interrupting prolonged sitting with brief bouts of light-intensity activity reduced blood pressure (BP) and plasma noradrenaline in type 2 diabetes (T2D). In a randomized crossover trial, 24 inactive overweight/obese adults with T2D (14 men; mean ± SD; 62 ± 6 years) consumed standardized meals during 3 × 8 h conditions: uninterrupted sitting (SIT); sitting + half-hourly bouts of walking (3.2 km/h for 3-min) (light-intensity walking); and sitting + half-hourly bouts of simple resistance activities for 3 min (SRAs), each separated by 6-14 days washout. Resting seated BP was measured hourly (mean of three recordings, ≥20-min postactivity). Plasma noradrenaline was measured at 30-min intervals for the first hour after meals and hourly thereafter. Compared with SIT, mean resting SBP and DBP were significantly reduced (P < 0.001) for both light-intensity walking (mean ± SEM; -14 ± 1/-8 ± 1 mmHg) and SRA (-16 ± 1/-10 ± 1 mmHg), with a more pronounced effect for SRA (P < 0.05 versus light-intensity walking). Similarly, mean plasma noradrenaline was significantly reduced for both light-intensity walking (-0.3 ± 0.1 nmol/l) and SRA (-0.6 ± 0.1 nmol/l) versus SIT, with SRA lower than light-intensity walking (P < 0.05). Mean resting heart rate was lowered by light-intensity walking (-3 ± 1 bpm; P < 0.05), but not SRA (-1 ± 1 bpm). Interrupting prolonged sitting with brief bouts of light-intensity walking or SRA reduces resting BP and plasma noradrenaline in adults with T2D, with SRA being more effective. Given the ubiquity of sedentary behaviors and poor adherence to structured exercise, this approach may have important implications for BP management in patients with T2D.

Sedentary behaviour (SB) has emerged as a risk factor for cardiovascular morbidity and mortality, independent of physical activity (PA) levels. Despite associations between SB and cerebrovascular disease, little research has assessed the influence of SB on cerebrovascular function, comprising cerebral blood flow (CBF), cerebral autoregulation (CA) and cerebrovascular carbon dioxide reactivity (CVR). This is of upmost importance since the maintenance of cerebrovascular function appears critical for cognition, mood and the prevention of cerebrovascular diseases. Consequently, the overarching aims of this thesis were to explore the effects of sitting on cerebrovascular function, cognition and mood and to explore the effect of breaking up sitting on these parameters. Study one assessed whether objectively measured workplace sitting and PA were associated with cognition and mood. Results showed workplace sitting was negatively associated with calm mood state, but not cognition. Standing and stepping whilst at work were positively associated with aspects of cognition (working memory and attention) and mood (positive affect and calm and content mood states), indicating PA throughout the workday should be encouraged as it may have beneficial effects on mental wellbeing and cognitive performance. In contrast to guidelines advising increasing light-intensity PA in the workplace, only moderate-intensity PA at work was positively associated with working memory, possibly indicating this higher intensity of PA should be encouraged during work hours to positively influence cognitive performance in desk workers. Study two aimed to determine the acute effects of a prolonged sitting period on cerebrovascular function, cognition and mood in healthy desk workers. Uninterrupted sitting for six hours reduced CBF and impaired aspects of CA but had no effect on CVR. Decreases in positive affect, and the alert and content mood states were also observed, but these were not related to the concurrent changes in cerebrovascular function. There was no change in cognition following prolonged sitting. Results may have important implications for the long-term mental and physical health of individuals who are repeatedly exposed to periods of uninterrupted sitting. Study three assessed the acute effects of breaking up sitting time on cerebrovascular function in healthy desk workers using two different walking break strategies. The decrease in CBF and CA observed following four hours of uninterrupted sitting was prevented using frequent, short duration walking breaks rather than less frequent, longer duration walking breaks. Results further demonstrate that prolonged uninterrupted sitting impairs cerebrovascular function and suggest that the frequency of the breaks used to interrupt sitting is an important component to preserve aspects of function. In contrast, both walking break strategies caused a larger increase in CVR compared to prolonged sitting. This indicates that, for this aspect of cerebrovascular function, any duration or frequency of PA may have acute benefits. Study four assessed whether using a computer-based prompting software designed to break up prolonged sitting at work altered cerebrovascular function, cognition and mood in healthy office workers. Following the intervention, workplace sitting was reduced and replaced predominantly by increased time spent standing. This reduction in sitting improved aspects of CA but had no influence on other measures of cerebrovascular function, cognition or mood. Results provide preliminary evidence that long-term reductions in SB may improve aspects of cerebrovascular function. Overall, the major findings of this thesis are that prolonged, uninterrupted sitting acutely impairs aspects of cerebrovascular function, however this can be prevented by breaking up sitting with short duration, regular walking breaks. Prolonged sitting also acutely impairs aspects of mood but not cognition. Taken together this thesis provides the first evidence that SB negatively effects cerebrovascular function and further research should explore whether this leads to heightened cerebrovascular disease risk.

To compare the effects of 4 hours of laboratory-based regular activity breaks (RABs) and prolonged sitting (SIT) on subsequent 48-h free-living interstitial glucose levels in a group of healthy adults. In this randomized crossover trial, participants completed two 4-h laboratory-based interventions commencing at ~5:00 pm: (1) SIT and (2) SIT interrupted with 3 min of body weight resistance exercise activity breaks every 30 min (RABs). Continuous glucose monitoring was performed during the intervention and for 48-h after, during which time participants returned to a free-living setting. Twenty-eight adults (female n = 20, mean ± SD age 25.5 ± 5.6 years, body mass index 29.2 ± 6.9 kg/m2) provided data for this analysis. During the intervention period, RABs lowered mean interstitial glucose by 8.3% (-0.47 mmol/L/4 h, 95% confidence interval [CI] -0.74 to -0.20; p = 0.001) and area under the curve (AUC) by 8.9% (-2.01 mmol/L/4 h, 95% CI -3.05 to -0.97; p < 0.001) compared to SIT. Measures of glycaemic variability were not significantly different during the intervention. There were no significant differences in mean glucose and AUC between conditions during the first nocturnal period and 24-h post intervention. When compared to SIT, RABs increased continuous overall net action of glucose at 1 h and SD glucose by 22% (0.18 mmol/L, 95% CI 0.03 to 0.29; p = 0.018) and 26% (95% CI 4.9 to 42.7; p = 0.019) in the first nocturnal period and by 10% (0.09 mmol/L, 95% CI 0.01, 0.17; p = 0.025) and 15% (95% CI 6.6 to 22.4; p = 0.001) in the 24-h post intervention period, respectively. Performing activity breaks in the evening results in acute reductions in interstitial glucose concentrations; however, the magnitude of these changes is not maintained overnight or into the following 48 hours.

Both exercise and breaks in prolonged sitting can reduce blood pressure (BP) in older overweight/obese adults. We investigated whether there is an additive hypotensive effect when exercise is combined with subsequent breaks in sitting. Sex differences and changes in plasma catecholamines as a potential candidate mechanism underlying BP responses were also examined. Sedentary older adults (n=67; 67±7 years; 31.2±4.1 kg/m2) completed 3 conditions in random order-sitting (SIT): uninterrupted sitting (8 hours, control); exercise+sitting (EX+SIT): sitting (1 hour), moderate-intensity walking (30 minutes), uninterrupted sitting (6.5 hours); exercise+breaks (EX+BR): sitting (1 hour), moderate-intensity walking (30 minutes), sitting interrupted every 30 minutes with 3 minutes of light-intensity walking (6.5 hours). Serial BP and plasma epinephrine/norepinephrine measurements occurred during 8 hours. The 8-hour average systolic and diastolic BP (mm Hg 95% CI) was lower in EX+SIT -3.4 (-4.5 to -2.3), -0.8 (-1.6 to -0.04), and EX+BR -5.1 (-6.2 to -4.0), -1.1 (-1.8 to -0.3), respectively, relative to SIT (all P <0.05). There was an additional reduction in average systolic BP of -1.7 (-2.8 to -0.6) in EX+BR relative to EX+SIT ( P=0.003). This additional reduction in systolic BP was driven by women -3.2 (-4.7 to -1.7; P<0.001 EX+BR versus EX+SIT). Average epinephrine decreased in EX+SIT and EX+BR in women (-13% to -12%) but increased in men (+12% to +23%), respectively, relative to SIT ( P<0.05). No differences in average norepinephrine were observed. Morning exercise reduces BP during a period of 8 hours in older overweight/obese adults compared with prolonged sitting. Combining exercise with regular breaks in sitting may be of more benefit for lowering BP in women than in men. Clinical Trial Registration- URL: https://www.anzctr.org.au . Unique identifier: ACTRN12614000737639.

This study aimed to determine whether interrupting prolonged sitting with three different walking-bout schedules improves glycemic metabolism relative to continuous prolonged sitting in sedentary adults. In a randomized, crossover trial, 16 inactive healthy adults (7 men, 24 ± 3 yr old) completed four 26-h laboratory sessions, including 22.5 h in an energy expenditure (EE)-testing calorimeter chamber. The four 9-h intervention periods were as follows: 9-h uninterrupted sitting (SIT), 30-min sitting/3-min brisk (60% V˙O2max) treadmill walk (WALK3), 45-min sitting/5-min (WALK5), or 60-min sitting/8-min (WALK8). Coprimary outcomes included the difference in the mean interstitial glucose concentration, total area under the curve (tAUC), and incremental area under the curve (iAUC) for the entire 26 and 9 h (intervention period) during three activity-bout conditions compared with SIT. Compared with SIT, the 26-h mean glucose concentration was attenuated in WALK8 (Δmean -0.22 mmol·L [95% confidence interval = -0.43 to -0.001], P = 0.048) without adjustment for EE and attenuated in WALK3 (Δ-0.47 mmol·L [-0.75 to -0.10]), WALK5 (Δ-0.47 mmol·L [-0.83 to -0.10]), and WALK8 (Δ-0.53 mmol·L [-0.92 to -0.13]) after adjustment for EE (all P < 0.01). The 26-h tAUC was reduced in WALK3 (Δ-11.18 mmol·L per 26 h [-20.07 to -2.29]), WALK5 (2.12.67 mmol·L per 26 h [-22.54 to -2.79]), and WALK8 (Δ-13.85 mmol·L per 26 h [-24.60 to -3.10]) (all P < 0.01), as well as the iAUC (all P < 0.05), only after adjustment for EE. The 9-h mean glucose concentration, tAUC, and iAUC decreased in the three activity-break conditions regardless of EE adjustment (all P < 0.05). All three walking-bout conditions improved glycemic metabolism compared with SIT, independent of EE, in inactive, healthy adults.

To determine whether interrupting prolonged sitting with three different activity breaks has both acute and chronic effects on postprandial lipid metabolism immediately after the activity-break period and on the following day, this study is a secondary analysis of an experimental research, which included 16 sedentary healthy adults (7 men, 24±3years, BMI 22.2±2.3kg/m2 ) who completed four 26-h laboratory trials. Participants spent 22.5hours in a whole room calorimeter for testing energy expenditure (EE), including a 9-h activity-break period: (a) 9-h prolonged sitting (SIT); (b) 3minutes of brisk walking (60% VO2max ) in between every 30-min sitting bout (WALK3), (c) 5minutes every 45-min (WALK5), and (d) 8minutes every 60-min (WALK8). Total area under the curve (tAUC) and incremental AUC (iAUC) for 2-h postprandial serum triglyceride (TG) levels and non-esterified fatty acid (NEFA) levels were examined immediately after the 9-h trial (post-dinner) and the next morning (post-breakfast). WALK8 reduced the post-breakfast TG tAUC by 11% (P=.041) relative to SIT, and the effect was attenuated after adjustment for EE. The tAUC and iAUC indicated no significant treatment effects on post-dinner TG and NEFA, and post-breakfast NEFA in any of the activity-break trials. EE was positively associated with the post-breakfast NEFA iAUC (unstandardized β=0.17µmol/L/MJ [0.05-0.28], P=.006). There was a chronic effect of interrupting sitting with short bouts (8minutes) of brisk walking every 60minutes on postprandial lipemia the following morning after intervention, and higher activity bout-induced EE may be more effective in sedentary, healthy adults.

Prolonged sitting contributes to cardiovascular disease (CVD) risk. The underlying mechanisms are unknown but may include changes in arterial function and vasoactive mediators. We examined the effects of prolonged unbroken sitting, relative to regular active interruptions to sitting time, on arterial function in adults at increased CVD risk. In a randomized crossover trial, 19 sedentary overweight/obese adults (mean ± SD age 57 ± 12 yr) completed 2 laboratory-based conditions: 5 h uninterrupted sitting (SIT) and 5 h sitting interrupted every 30 min by 3 min of simple resistance activities (SRA). Femoral artery function [flow-mediated dilation (FMD)], blood flow, and shear rate were measured at 0 h, 30 min, 1 h, 2 h, and 5 h. Brachial FMD was assessed at 0 and 5 h. Plasma was collected hourly for measurement of endothelin-1 (ET-1), nitrates/nitrites, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). There was a significant decline in femoral artery FMD, averaged over 5 h in the SIT condition, relative to SRA (P < 0.001). Plasma ET-1 total area under the curve over 5 h increased in the SIT condition compared with SRA (P = 0.006). There was no significant difference between conditions in femoral or brachial shear rate, brachial FMD, nitrates/nitrites, VCAM-1, or ICAM-1 (P > 0.05 for all). Five hours of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating ET-1 in overweight/obese adults. There is the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting.NEW & NOTEWORTHY This is the first study to examine the effect of prolonged sitting on arterial function in adults at increased cardiovascular disease risk. We have shown that 5 h of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating endothelin-1 in overweight/obese adults. There is now the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting.

Objective: This study examined acute effects of interrupting prolonged sitting with short activity breaks on postprandial glucose/insulin responses and estimations of insulin sensitivity in adults with type 1 diabetes (T1D). Method: In a randomized crossover trial, eight adults (age = 46 ± 14 years [mean ± SD], body mass index [BMI] = 27.2 ± 3.8 kg/m2) receiving continuous subcutaneous insulin infusion (CSII) therapy completed two 6-h conditions as follows: uninterrupted sitting (SIT) and sitting interrupted with 3-min bouts of simple resistance activities (SRAs) every 30 min. Basal and bolus insulin were standardized across conditions except in cases of hypoglycemia. Postprandial responses were assessed using incremental area-under-the-curve (iAUC) and total AUC (tAUC) from half-hourly venous sampling. Meal-based insulin sensitivity determined from glucose sensor and insulin pump (SiSP) was assessed from flash continuous glucose monitor and insulin pump data. Outcomes were analyzed using mixed models adjusted for sex, BMI, treatment order, and preprandial values. Results: Glucose iAUC did not differ by condition (SIT: 19.8 ± 3.0 [estimated marginal means ± standard error] vs. SRA: 14.4 ± 3.0 mmol.6 h.L-1; P = 0.086). Despite CSII being standardized between conditions, insulin iAUC was higher in SRA compared to SIT (137.1 ± 22.7 vs. 170.9 ± 22.7 mU.6 h.L-1; P < 0.001). This resulted in a lower glucose response relative to the change in plasma insulin in SRA (tAUCglu/tAUCins: 0.32 ± 0.02 vs. 0.40 ± 0.02 mmol.mU-1; P = 0.03). SiSP was also higher at dinner following the SRA condition, with no between-condition differences at breakfast or lunch. Conclusion: Regularly interrupting prolonged sitting in T1D may increase plasma insulin and improve insulin sensitivity when meals and CSII are standardized. Future studies should explore underlying mechanistic determinants and the applicability of findings to those on multiple daily injections. Trial Registration: Australian and New Zealand Clinical Trial Registry Identifier-ACTRN12618000126213 (www.anzctr.org.au).

We hypothesized that differences in cardiac baroreflex sensitivity (BRS) would be independently associated with aortic stiffness and augmentation index (AI), clinical biomarkers of cardiovascular disease (CVD) risk, among young sedentary and middle-aged/older sedentary and endurance-trained adults. A total of 36 healthy middle-aged/older (age 55-76 years, n=22 sedentary; n=14 endurance-trained) and 5 young sedentary (age 18-31 years) adults were included in a cross-sectional study. A subset of the middle-aged/older sedentary adults (n=12) completed an 8-week aerobic exercise intervention. Invasive brachial artery blood pressure waveforms were used to compute spontaneous cardiac BRS (via sequence technique) and estimated aortic pulse wave velocity (PWV) and AI (AI, via brachial-aortic transfer function and wave separation analysis). In the cross-sectional study, cardiac BRS was 71% lower in older compared with young sedentary adults (P<0.05), but only 40% lower in older adults who performed habitual endurance exercise (P=0.03). In a regression model that included age, sex, resting heart rate, mean arterial pressure (MAP), body mass index and maximal exercise oxygen uptake, estimated aortic PWV (β±SE = −5.76 ± 2.01, P=0.01) was the strongest predictor of BRS (Model R2=0.59, P<0.001). The 8 week exercise intervention improved BRS by 38% (P=0.04) and this change in BRS was associated with improved aortic PWV (r=−0.65, P=0.044, adjusted for changes in MAP). Age- and endurance exercise-related differences in cardiac BRS are independently associated with corresponding alterations in aortic PWV among healthy adults, consistent with a mechanistic link between variations in the sensitivity of the baroreflex and aortic stiffness with age and exercise.

ABSTRACTPurposePhysical exercise may enhance cognitive functions, including inhibitory control. Despite increasing evidence, there remains a need for robust evidence on long-term interventions targeting inhibition in healthy, sedentary young adults. We investigated the effects of a 12-wk cardiovascular exercise program on this population’s behavioral and neuroelectric measures of inhibitory control.MethodsSedentary young adults were randomized into an experimental group (n = 32) or a passive control group (n = 30). The experimental group completed a cycling ergometer program consisting of 6 wk of moderate-intensity continuous exercise, followed by 6 wk of moderate- to high-intensity interval exercise. Inhibitory control was assessed at baseline (pretest), after 6 wk (midtest), and after the intervention (posttest) using a modified flanker task with EEG recordings. Assessed outcomes included response time (RT) and event-related potentials (the amplitude and latency of the N2 and P3b components).ResultsThe experimental group exhibited a progressive reduction in RT for incongruent trials across all time points (pretest to midtest, midtest to posttest, and pretest to posttest) without compromising accuracy. The control group showed RT reductions only from pretest to posttest, with a decline in overall accuracy. Neuroelectric analyses revealed decreased N2 amplitudes and faster P3b latencies in the experimental group from midtest to posttest during incongruent trials. The control group demonstrated increased N2 amplitudes from pretest to midtest and pretest to posttest during congruent trials.ConclusionsA 12-wk cardiovascular exercise intervention combining moderate-intensity continuous exercise and moderate- to high-intensity interval exercise enhances both behavioral and neuroelectric indices of inhibitory control in sedentary young adults. These findings highlight the potential of exercise programs as an accessible and effective strategy for improving cognitive health, especially in healthy but sedentary adults.

Carbohydrate-enriched diets and sedentary behavior contribute to diabetes risk. However, their impacts on glucose metabolism in abdominal (ASAT) and gluteal subcutaneous adipose tissues (GSAT), especially considering sex differences, remain unexplored. Twenty (median age 29.2 years, median BMI 23.1 kg/m2) healthy participants (10 females) underwent mixed-feeding trials lasting 320 min, with carbohydrate-enriched meals following either prolonged sitting (SIT) or interrupted prolonged sitting (ACTIVE) in a randomized crossover design. Continuous glucose monitoring (CGM) was inserted simultaneously at abdominal and gluteal fat depots. Body composition was quantified by dual-energy x-ray absorptiometry. Oral glucose tolerance test was performed for measuring insulin sensitivity and resistance. In vitro experiments using paired human abdominal and gluteal preadipocyte cell lines were conducted to investigate molecular mechanisms. In the SIT trial, GSAT CGM showed a slower increase in interstitial glucose during lunch compared to ASAT CGM, particularly in females. In the ACTIVE trial, intermittent brisk walking led to numerically lower interstitial glucose levels in both ASAT and GSAT CGM, with the most significant impact observed in female ASAT CGM. While males with higher hepatic insulin resistance or android fat displayed a notable correlation with decreased interstitial glucose levels in the ACTIVE trial. Our in vitro experiments further revealed steady glucose uptake (GLUT1 expression) and de novo lipogenesis (ChREBP protein) were specifically enhanced in gluteal adipocytes during post-feeding 3-6 h. Breaking up prolonged sitting improves postprandial glucose control. Whereas gluteal fat depot may play roles to stabilize carbohydrate-enriched diets-induced hyperglycemia.

Mindfulness-acceptance commitment interventions in sport and exercise contexts have been helpful to increasing a positive psycho-physiological state among competitive athletes and recreational exercise participants. In the current study, we sought to extend research in this area by identifying the effect of a brief-mindfulness intervention on psychophysiological functioning among healthy but sedentary young adults. Our mixed gender sample (n = 42) of inactive individuals performed a brief cycling task without training (control condition) followed by task completion with brief mindfulness training (15-minute audio engagement with mindfulness techniques and specific present moment 'anchors'). We found that participants self-reported more accurate ratings of perceived exertion (i.e., self-ratings better matched actual physiological indices of exertion) following the mindfulness intervention, suggesting that mindfulness techniques can increase bodily awareness. Better body awareness may be useful to helping sedentary participants appreciate physiological changes experienced through exercise. The mindfulness manipulation also increased participants' absorption into the activity, suggesting greater attentiveness to the exercise task with less distraction from irrelevant external and internal cues. In sum, mindfulness may be a complementary psychological training tool for inactive, sedentary young adults attempting to re-engage with exercise. We provide recommendations for future research.