Purpose: Previous studies revealed first evidence of a negative association between time spent sitting and affective states. In particular, prolonged sitting time is a potential risk factor for decreasing momentary affective states. However, whether the social and environmental context might moderate these effects is mainly unknown.

Methods: In four independent studies, we collected data from 308 participants (50.3% female, age: 27.4 yrs., range: 17-66) by using the ecological momentary assessment approach (EMA). Sitting time was continuously assessed via a thigh-worn accelerometer, and affective states were captured multiple times per day via electronic diaries on study smartphones. Moreover, we used a cutting-edge algorithm to assess social and environmental context information “just in time”. That means the accelerometer transferred data to the smartphone and whenever a participant remained in an uninterrupted sitting bout of ≥ 20/30 minutes, the smartphone triggered contextual questions (i.e., alone vs. not-alone; and work vs. home) to the participants.

Results: Social and environmental context significantly (P values < 0.001) moderated the effects of sitting bouts on affective states. In practice, sitting bouts in company with others were associated with higher valence levels and energetic arousal. Furthermore, sitting bouts during leisure time were associated with higher levels of valence and calmness and lower levels of energetic arousal. Significant interaction analyses revealed that participants felt best while sitting during leisure episodes together with others.

Discussion: The study showed that the social and environmental context moderated the association between sitting bouts and momentary affective states. Sitting with others, sitting during leisure time, and especially sitting during leisure time and with others, was associated with better feelings. The results indicate that not all sitting bouts are equally bad for well-being. Moreover, our valid ecological findings may inform future intervention studies, which target to increase well-being to focus mainly on sitting bouts during work conditions and while being alone.

Purpose: Sedentary behaviour (SB) especially sitting for large proportions of the day has become a public health concern. Due to the nature of their occupation, office workers are exposed to a high risk of engaging in SB and prolonged sitting during their everyday lives. The aim of this ecological momentary assessment (EMA) study was to describe the physical activity (PA) and SB patterns of office workers, identify potential health risks, and to inform the development of future interventions to reduce sitting and promote PA.

Methods: Seventy-seven office workers participated in a seven-day EMA-study. Time spent in PA and SB was assessed via thigh-worn accelerometers worn during waking hours. Participants’ habit to perform tasks while standing (5-point likert scale) and stages of change (SOC) for SB reduction were assessed using self-reports before starting the EMA period. Descriptive analyses were conducted for self-report and accelerometer data.

Results: Data of 69 participants (mage = 46.2 ±10.6; 86% female) were included in the analyses. 93% reported that they were in a preparation or action/maintenance SOC for SB reduction. Self-reported habit to perform tasks while standing was m = 2.9 (±0.95). Participants provided valid activity monitor data for 287 work days in total. On average, accelerometers were worn on 15.7 h/day. Office workers spent 10.6 h/day in SB, 3.3 h/day standing and 1.8 h/day in PA while taking 8934 steps/day. Sedentary bouts <5 min were the most frequent (22.24/day) while bouts >30 min occurred less often (6.26/day), but accounted for 5.8h/day (55%).

Conclusions: Office workers spent two thirds of their work days in SB. Regardless of their high motivation to spend less time sedentary and their above average PA, office workers spent more time in SB than the population average and accumulated more than half of the total time in prolonged bouts of >30 min. These findings indicate an intention behaviour gap for time spent in SB. Interventions aiming to reduce time spent in SB should focus on volitional strategies such as behaviour change techniques like action planning, which facilitate overcoming this gap.

Purpose: Sedentary behaviours (SB) are risk factors for poor cardiometabolic health in youth, and novel intervention strategies are needed. The purpose of this pilot study was to determine the feasibility of: 1) interrupting prolonged SB in a free-living setting; and 2) leveraging multiple measures to assess relationships between objectively measured SB, glucose homeostasis, and behavioural contexts in a free-living setting in adolescents.

Methods: Healthy youth (N=15; mean(SD) age=13.1(1.0) years, 66.7% female, 66.7% healthy weight) completed two 1-week conditions in random order: 1) habitual activity; or 2) wrist-worn device-prompted interruptions of prolonged (30+ minutes) SB. Participants simultaneously wore an ActivPAL accelerometer on the right thigh, a Freestyle Libre continuous glucose monitor (CGM) on the back of the upper arm, and completed ecological momentary assessment (EMA) surveys up to 7 times/day on self-reported behaviours and contexts.

Results: 93% of participants completed both assessments. There were no significant differences in accelerometer-measured SB characteristics between the conditions. Across the two assessment weeks, participants recorded an average of 7.6 (1.3) sitting bouts lasting longer than 30 min/day, and 3.2 (0.9) sitting bouts lasting longer than 60 min/day for an average of 839.4 (106.0) and 658.1 (108.0) min/day, respectively, spent in sedentary bouts lasting longer than 30 or 60 minutes at a time. They averaged 70 sit-to-stand transitions per day. There were no significant differences between the conditions on compliance with the multiple measures. Participants provided an average of 6.4 (1.7) valid days (10+hrs/day) per week of accelerometer data. Participants had 85% compliance with 24-hour CGM wear and contributed an average of 6.7 (1.9) days/week. There was a 65.0% compliance rate with the EMA surveys. Participants who were 12+ years old, male, had mothers with less than a college education, or who had overweight/obesity had higher EMA survey response rates.

Conclusions: Employing multiple modalities to assess SB, glucose homeostasis, and EMA-measured SB behaviours and contexts is feasible in a free-living setting in youth. However, more work is needed to better understand how to effectively prompt interruptions in prolonged sedentary time using multiple modalities in free-living settings with adolescents.