JMIR Publications

ABSTRACT

Background:

Previous studies of affective state-sedentary behavior (SB) associations have not accounted for their potentially time-varying nature and have utilized inconsistent SB measurement modalities. We investigated the within-day, time-varying associations between device-measured SB, ecological momentary assessment (EMA)-reported screen-based SB, and concurrently reported affective states (negative/positive) in youth.

Objective:

This proof-of-concept study had objective of informing the methodology of future work on free-living behavior-affective state associations.

Methods:

Fifteen adolescents (mean [SD] age= 13.07[1.03] years, 66.67% female, 40.00% Hispanic, 66.67% healthy weight) wore thigh-mounted activPAL accelerometers and simultaneously reported on their screen-based SBs and concurrent affective states via EMA for 7-14 days (N=636 occasions). Time-varying effect models (varying slopes) examined how each measure of SB was associated with concurrent affective states from 7am-8pm.

Results:

The time-varying effect model plots revealed that these associations varied in strength across the day. Specifically, device-based SB was related to greater concurrent negative affect only after ~5:00pm and was unrelated to concurrent positive affect. Screen-based SB was related to greater concurrent negative affect only from 7am to ~9am. It was also related to greater concurrent positive affect from 7am to ~9:30am and from ~3pm to ~7pm.

Conclusions:

We provide preliminary evidence to suggest that future confirmatory studies investigating the SB-affective state relationship should consider the time-varying nature of these associations and SB measurement modality. There may be critical time windows when specific types of SBs co-occur with affect, suggesting that interventions may need tailoring by time of day and type of SB if future studies can replicate our findings.