Equivalence Curves for Healthy Lifestyle Choices

The association between reallocations of time and health using compositional data analysis: a systematic scoping review with an interactive data exploration interface

BACKGROUND

How time is allocated influences health. However, any increase in time allocated to one behaviour must be offset by a decrease in others. Recently, studies have used compositional data analysis (CoDA) to estimate the associations with health when reallocating time between different behaviours. The aim of this scoping review was to provide an overview of studies that have used CoDA to model how reallocating time between different time-use components is associated with health.

METHODS

A systematic search of four electronic databases (MEDLINE, Embase, Scopus, SPORTDiscus) was conducted in October 2022. Studies were eligible if they used CoDA to examine the associations of time reallocations and health. Reallocations were considered between movement behaviours (sedentary behaviour (SB), light physical activity (LPA), moderate-to-vigorous physical activity (MVPA)) or various activities of daily living (screen time, work, household chores etc.). The review considered all populations, including clinical populations, as well as all health-related outcomes.

RESULTS

One hundred and three studies were included. Adiposity was the most commonly studied health outcome (n = 41). Most studies (n = 75) reported reallocations amongst daily sleep, SB, LPA and MVPA. While other studies reported reallocations amongst sub-compositions of these (work MVPA vs. leisure MVPA), activity types determined by recall (screen time, household chores, passive transport etc.) or bouted behaviours (short vs. long bouts of SB). In general, when considering cross-sectional results, reallocating time to MVPA from any behaviour(s) was favourably associated with health and reallocating time away from MVPA to any behaviour(s) was unfavourably associated with health. Some beneficial associations were seen when reallocating time from SB to both LPA and sleep; however, the strength of the association was much lower than for any reallocations involving MVPA. However, there were many null findings. Notably, most of the longitudinal studies found no associations between reallocations of time and health. Some evidence also suggested the context of behaviours was important, with reallocations of leisure time toward MVPA having a stronger favourable association for health than reallocating work time towards MVPA.

CONCLUSIONS

Evidence suggests that reallocating time towards MVPA from any behaviour(s) has the strongest favourable association with health, and reallocating time away from MVPA toward any behaviour(s) has the strongest unfavourable association with health. Future studies should use longitudinal and experimental study designs, and for a wider range of outcomes.

Daily and average associations of physical activity, social media use, and sleep among adolescent girls during the COVID-19 pandemic

Adolescents' daily lives have been disrupted during the Coronavirus disease 2019 (COVID-19) pandemic. It remains unclear how changes in adolescents' daily physical and social behaviours affect their sleep. The present study examined the daily and average effects of physical activity and social media use (i.e., video chatting, texting, and social networking sites) on adolescent girls' sleep during the COVID-19 pandemic. Adolescent girls aged 12-17 years (N = 93; 69% White) from a larger longitudinal study completed a 10-day daily diary protocol during state-mandated stay-at-home orders. Girls reported on daily sleep (duration, timing, quality), physical activity, and social media use during COVID-19. Multilevel modelling was used to examine the within- and between-person effects of physical activity and social media on sleep duration, timing, and quality during the 10-day period. Between-person associations indicate that youth with greater social media use (texting, video chatting, and social networking) and less physical activity had later sleep timing across the 10-day study period. Only video chatting was associated with shorter sleep duration. There were no within-person effects of physical activity or social media activities on sleep outcomes. Findings indicate that physical activity and social media use may impact later adolescent sleep timing during the COVID-19 pandemic. It will be critical for research to examine the potential long-term costs of delayed sleep timing, and whether targeting specific youth behaviours associated with sleep and circadian disruption improve mental and physical health during the COVID-19 pandemic and beyond.

The reciprocal interplay of physical activity and health‐related quality of life in children and adolescents: Evidence for both upward and downward spirals

OBJECTIVE

This study examines the bidirectional effect between physical activity (PA) and health-related quality of life in children and adolescents, focusing on within-person effects.

METHODS

PA and health-related quality of life were assessed in children and adolescents (N = 685, age: M = 10.29 years, SD = 1.35, range = 8-14), via self-report across four waves, each 6 months apart, and a random-intercept cross-lagged panel model with time-invariant cross-lagged effects was calculated.

RESULTS

Positive cross-lagged effects between prior PA and health-related quality of life 6 months later ( γ y  = 0.536, 95% CI [0.016, 1.055], p = .043, d = 0.11) and vice versa ( γ x  = 0.015, 95% CI [0.001, 0.030], p = .039, d = 0.12) were found. Furthermore, the random intercept correlation was significant ( T xy  = 3.622, 95% CI [2.204, 5.041], p < .001, d = 0.27).

CONCLUSIONS

The findings confirm known correlations between PA and health-related quality of life and extends them by indicating both an upward and downward spiral of PA and health-related quality of life in children and adolescents.

The Compositional Impacts of 2 Distinct 24-Hour Movement Behavior Change Patterns on Physical Fitness in Chinese Adolescents

BACKGROUND

The study aimed to examine predicted differences of 2 different behavior change patterns on physical fitness (PF).

METHODS

Participants were 241 students (51% girls) aged 11-14 years from China. Light physical activity, moderate to vigorous physical activity (MVPA), and sedentary behavior (SB) were objectively measured. Sleep was obtained by subtracting from awake time. According to Chinese National student PF standards, 5 components of PF, including body mass index, cardiorespiratory fitness, speed, muscular explosive power and strength endurance, and flexibility, were assessed. The effects of different time reallocations between 24-hour movement behaviors on PF were estimated based on adjusted compositional multiple linear regression models with isometric log ratios.

RESULTS

Compared with MVPA substituting for the remaining behaviors, MVPA replacing SB or light physical activity produced more favorable changes on the comprehensive PF score, cardiorespiratory fitness, explosive power, and speed. MVPA replacing 30 minutes of SB was associated with favorable changes in PF (+1.9 [0.53, 3.18] points), 50-m run (-0.17 [-0.31, -0.04] s), long-distance running (-5.54 s [for girls]/7.25 s [for boys]), and long jump (+0.05 [0.01, 0.09] m). When sleep replaced SB, PF improved.

CONCLUSIONS

MVPA substituting SB or light physical activity is a strategy with a greater improvement in PF.