Purpose: To assess the convergent validity of body-worn wearable camera still images (IMGs) for determining posture compared with activPAL (AP) classifications. Methods: The participants (n = 16, mean age 46.7 ± 23.8 years, 9 F) wore an Autographer wearable camera and an AP during three 2-hr free-living visits. IMGs were on average 8.47 s apart and were annotated with output consisting of events, transitory states, unknown, and gaps. The events were annotations that matched AP classifications (sit, stand, and move), consisting of at least three IMGs; the transitory states were posture annotations fewer than three IMGs; the unknowns were IMGs that could not be accurately classified; and the gaps were the time between annotations. For the analyses, the annotation and AP output were converted to 1-s epochs. The total and average length of visits and events were reported in minutes. Bias and 95% confidence intervals for event posture times from IMGs to AP were calculated to determine accuracy and precision. Confusion matrices using total AP posture times were computed to determine misclassification. Results: Forty-three visits were analyzed, with a total visit and event time of 5,027.73 and 4,237.23 min, respectively, and the average visit and event lengths being 116.92 and 98.54 min, respectively. Bias was not statistically significant for sitting, but was significant for standing and movement (0.84, −6.87, and 6.04 min, respectively). From confusion matrices, IMGs correctly classified sitting, standing, and movement (85.69%, 54.87%, and 69.41%, respectively) of total AP time. Conclusion: Wearable camera IMGs provide a good estimation of overall sitting time. Future work is warranted to improve posture classifications and examine the validity of IMGs in assessing activity-type behaviors.
Julian Martinez, Autumn E. Decker, Chi C. Cho, Aiden Doherty, Ann M. Swartz, John Staudenmayer, and Scott J. Strath
Elif Inan-Eroglu, Bo-Huei Huang, Leah Shepherd, Natalie Pearson, Annemarie Koster, Peter Palm, Peter A. Cistulli, Mark Hamer, and Emmanuel Stamatakis
Background: Thigh-worn accelerometers have established reliability and validity for measurement of free-living physical activity-related behaviors. However, comparisons of methods for measuring sleep and time in bed using the thigh-worn accelerometer are rare. The authors compared the thigh-worn accelerometer algorithm that estimates time in bed with the output of a sleep diary (time in bed and time asleep). Methods: Participants (N = 5,498), from the 1970 British Cohort Study, wore an activPAL device on their thigh continuously for 7 days and completed a sleep diary. Bland–Altman plots and Pearson correlation coefficients were used to examine associations between the algorithm derived and diary time in bed and asleep. Results: The algorithm estimated acceptable levels of agreement with time in bed when compared with diary time in bed (mean bias of −11.4 min; limits of agreement −264.6 to 241.8). The algorithm-derived time in bed overestimated diary sleep time (mean bias of 55.2 min; limits of agreement −204.5 to 314.8 min). Algorithm and sleep diary are reasonably correlated (ρ = .48, 95% confidence interval [.45, .52] for women and ρ = .51, 95% confidence interval [.47, .55] for men) and provide broadly comparable estimates of time in bed but not for sleep time. Conclusions: The algorithm showed acceptable estimates of time in bed compared with diary at the group level. However, about half of the participants were outside of the ±30 min difference of a clinically relevant limit at an individual level.
Oliver W.A. Wilson, Kelsey E. Holland, Lucas D. Elliott, Michele Duffey, and Melissa Bopp
Background: Investigating the impact of the COVID-19 pandemic on both physical activity (PA) and mental health is important to demonstrate the need for interventions. This study examined the apparent impact of the pandemic on college students’ PA, perceived stress, and depressive symptoms. Methods: From 2015 through 2020, data were collected at the beginning and end of the spring semester at a large Northeastern US university via an online survey assessing student demographics, PA, perceived stress, and depressive symptoms. Mixed ANOVA examined differences in PA and mental health changes over the spring semester between “normal” and COVID-19 circumstances. Two-way ANOVA examined the interaction between circumstance and changes in PA in relation to changes in mental health. Results: Participants (n = 1019) were predominately women and non-Hispanic white. There was a significant decline in PA and an increase in perceived stress under COVID-19, but not normal, circumstances and a significant increase in depressive symptoms under COVID-19, but not normal, circumstances among women. Conclusions: A significant decline in PA and mental health among college students occurred under COVID-19 circumstances, and PA did not appear to protect against deterioration in mental health. Proactive and innovative policies, programs, and practices to promote student health and well-being must be explored immediately.
Bryndan W. Lindsey, Ali Boolani, Justin J. Merrigan, Nelson Cortes, Shane V. Caswell, and Joel R. Martin
Background: The COVID-19 pandemic has changed our working environment and divided workers into essential or nonessential statuses. Employment status is a major factor determining the amount of physical activity performed. Our purpose was to understand how employment status affects physical activity and sitting time. Methods: Between April 13 and May 4, 2020, 735 full-time employed individuals responded to a survey investigating daily life and overall health during the COVID-19 pandemic. Participants reported how much physical activity they had performed in the last 7 days. Multiple linear regressions were performed for physical activity and sitting time. Results: Physical activity was not associated with employment status. An interaction effect between hours worked and employment status was found for sitting time. Conclusions: Employment status was not related to physical activity; however, it did affect the amount of time spent sitting, with nonessential employees sitting more and working more hours than essential employees. Because greater amounts of daily total sitting time have been associated with increased risk of all-cause mortality, it is important that increased sitting time be attenuated by greater physical activity.
Stephanie G. Kerrigan, Evan M. Forman, Dave Williams, Mitesh Patel, Caitlin Loyka, Fengqing Zhang, Ross D. Crosby, and Meghan L. Butryn
Background: Financial incentives and feedback on behavior offer promise for promoting physical activity. However, evidence for the effect of each of these techniques is inadequate. The present study evaluated the effects of daily versus weekly feedback and incentives contingent on reaching a daily walking goal versus noncontingent incentives in a 2 × 2 trial. Methods: Participants (N = 57) had a body mass index >25 kg/m2 and were insufficiently active. Participants received a daily walking goal that adapted weekly. Results: Participants receiving daily feedback increased daily steps (P = .03) more than those receiving weekly feedback. Participants receiving contingent incentives did not significantly increase steps (P = .12) more than those receiving noncontingent incentives. A trend-level effect (P = .09) suggested that there may be an interaction such that the combination of daily feedback and contingent incentives is most effective. Conclusions: Results indicate that feedback is an important component of remotely delivered PA interventions and that evaluating each component of low-intensity interventions may help to improve efficacy. Moreover, results indicate that possible synergistic effects of feedback and rewards should be investigated further to help optimize interventions.
John Bellettiere, Fatima Tuz-Zahra, Jordan A. Carlson, Nicola D. Ridgers, Sandy Liles, Mikael Anne Greenwood-Hickman, Rod L. Walker, Andrea Z. LaCroix, Marta M. Jankowska, Dori E. Rosenberg, and Loki Natarajan
Little is known about how sedentary behavior (SB) metrics derived from hip- and thigh-worn accelerometers agree for older adults. Thigh-worn activPAL (AP) micro monitors were concurrently worn with hip-worn ActiGraph (AG) GT3X+ accelerometers (with SB measured using the 100 counts per minute [cpm] cut point; AG100cpm) by 953 older adults (age 77 ± 6.6, 54% women) for 4–7 days. Device agreement for sedentary time and five SB pattern metrics was assessed using mean error and correlations. Logistic regression tested associations with four health outcomes using standardized (i.e., z scores) and unstandardized SB metrics. Mean errors (AP − AG100cpm) and 95% limits of agreement were: sedentary time −54.7 [−223.4, 113.9] min/day; time in 30+ min bouts 77.6 [−74.8, 230.1] min/day; mean bout duration 5.9 [0.5, 11.4] min; usual bout duration 15.2 [0.4, 30] min; breaks in sedentary time −35.4 [−63.1, −7.6] breaks/day; and alpha −.5 [−.6, −.4]. Respective Pearson correlations were: .66, .78, .73, .79, .51, and .40. Concordance correlations were: .57, .67, .40, .50, .14, and .02. The statistical significance and direction of associations were identical for AG100cpm and AP metrics in 46 of 48 tests, though significant differences in the magnitude of odds ratios were observed among 13 of 24 tests for unstandardized and five of 24 for standardized SB metrics. Caution is needed when interpreting SB metrics and associations with health from AG100cpm due to the tendency for it to overestimate breaks in sedentary time relative to AP. However, high correlations between AP and AG100cpm measures and similar standardized associations with health outcomes suggest that studies using AG100cpm are useful, though not ideal, for studying SB in older adults.
Hyeonho Yu, Pamela H. Kulinna, and Shannon C. Mulhearn
Background: Environmental provisions can boost students’ discretionary participation in physical activity (PA) during lunchtime at school. This study investigated the effectiveness of providing PA equipment as an environmental intervention on middle school students’ PA levels and stakeholders’ perceptions of the effectiveness of equipment provisions during school lunch recess. Methods: A baseline–intervention research design was used in this study with a first baseline phase followed by an intervention phase (ie, equipment provision phase). A total of 514 students at 2 middle schools (school 1 and school 2) in a rural area of the western United States were observed directly using the System for Observing Play and Leisure Activity in Youth instrument. Interviews were conducted with stakeholders. Paired-sample t tests and visual analysis were conducted to explore differences in PA levels by gender, and common comparison (with trustworthiness measures) was used with the interview data. Results: The overall percentage of moderate to vigorous PA levels was increased in both schools (ranging from 8.0% to 24.0%). In school 2, there was a significant difference in seventh- and eighth-grade students’ moderate to vigorous PA levels from the baseline. Three major themes were identified: (1) unmotivated, (2) unequipped, and (3) unquestionable changes (with students becoming more active). Conclusions: Environmental supports (access, equipment, and supervision) significantly and positively influenced middle school students’ lunchtime PA levels.
Danilo Fernandes da Silva, Shuhiba Mohammad, Taniya Singh Nagpal, Sara Carolina Scremin Souza, Rachel C. Colley, and Kristi Bree Adamo
Background: The authors examined whether or not ≤3 days wearing Actical® accelerometers provided acceptable results in comparison with the recommendation of ≥4 days in women across gestation. Methods: A total of 26, 76, and 57 participants at early, mid, and late pregnancy, respectively, were assessed. Participants were instructed to wear the device for 7 days and women who wore it for ≥4 days were included. For each participant, 3, 2, and 1 day(s) were randomly selected. Paired comparisons, intraclass correlations coefficients, and kappa statistics were performed for ≥4 days (criterion) versus 3, 2, and 1 day(s). Averages (in minutes per day) of sedentary time, light, moderate, vigorous, moderate to vigorous physical activity (PA) and steps per day were examined. Results: When 3 valid days were compared with the criterion, no significant differences were found for any gestational period. The intraclass correlations coefficients were “high” for all PA-related variables. The k values varied from .819 to .838 across pregnancy (“strong”). Two and 1 valid day(s) versus the criterion showed significant differences in some PA intensities, reduced intraclass correlations coefficients, “moderate” k values for 2 valid days (.638–.788) and “minimal-to-moderate” k values for 1 valid day (.367–.755). Conclusion: In pregnant women during early, mid, and late pregnancy, PA data obtained from 3 valid days of wear was equivalent and agreed with ≥4 valid days.