Stability Of Physical Activity Research Articles

Assessing the relationship between routine and schizophrenia symptoms with passively sensed measures of behavioral stability

Increased stability in one’s daily routine is associated with well-being in the general population and often a goal of behavioral interventions for people with serious mental illnesses like schizophrenia. Assessing behavioral stability has been limited in clinical research by the use of retrospective scales, which are susceptible to reporting biases and memory inaccuracies. Mobile passive sensors, which are less susceptible to these sources of error, have emerged as tools to assess behavioral patterns in a range of populations. The present study developed and examined a metric of behavioral stability from data generated by a passive sensing system carried by 61 individuals with schizophrenia for one year. This metric—the Stability Index—appeared orthogonal from existing measures drawn from passive sensors and matched the predictive performance of state-of-the-art features. Specifically, greater stability in social activity (e.g., calls and messages) were associated with lower symptoms, and greater stability in physical activity (e.g., being still) appeared associated with elevated symptoms. This study provides additional support for the predictive value of individualized over population-level data in psychiatric populations. The Stability Index offers also a promising tool for generating insights about the impact of behavioral stability in schizophrenia-spectrum disorders.

Momentary Affective States Are Associated with Momentary Volume, Prospective Trends, and Fluctuation of Daily Physical Activity.

Several interventions aiming to enhance physical activity in everyday life showed mixed effects. Affective constructs are thought to potentially support health behavior change. However, little is known about within-subject associations between momentary affect and subsequent physical activity in everyday life. This study analyzed the extent to which three dimensions of affective states (valence, calmness, and energetic arousal) were associated with different components of daily activity trajectories. Sixty-five undergraduates’ students (Age: M = 24.6; SD = 3.2; females: 57%) participated in this study. Physical activity was assessed objectively through accelerometers during 24 h. Affective states assessments were conducted randomly every 45 min using an e-diary with a six-item mood scale that was especially designed for ambulatory assessment. We conducted three-level multi-level analyses to investigate the extent to which momentary affect accounted for momentary volume, prospective trends, and stability vs. fluctuation of physical activity in everyday life. All three affect dimensions were significantly associated with momentary activity volumes and prospective trends over 45 min periods. Physical activity didn’t fluctuate freely, but featured significant autocorrelation across repeated measurements, suggesting some stability of physical activity across 5-min assessments. After adjusting for the autoregressive structure in physical activity assessments, only energetic arousal remained a significant predictor. Feeling energized and awake was associated with an increased momentary volume of activity and initially smaller but gradually growing decreases in subsequent activity within the subsequent 45 min. Although not related to trends in physical activity, higher valence predicted lower stability in physical activity across subsequent 45 min, suggesting more short-term fluctuations in daily activity the more participants reported positive affective valence. The current analyses afford interesting insight into within-subject associations between momentary affect and activity-trajectories in everyday life. Energetic arousal emerged as the only meaningful predictor of physical activity in daily life after adjusting for autoregression. A significant effect of valence on short-term activity fluctuations might indicate that activity interventions would benefit from taking into account enhancement of positive affective valence in everyday life. Moments of enhanced valence may scaffold attempts helping inactive people to get started with daily activities and overcome periods of inactivity in everyday life.

Prevalence and stability of active play, restricted movement and television viewing in infants

This study describes engagement in and stability of physical activity and sedentary behaviours in early life, and assesses associations with sex, maternal education and developmental stage. Maternal-report data at child age 4, 9 and 20 months were collected from 542 families in the Melbourne Infant Feeding Activity and Nutrition Trial Program. Parents estimated average time per day their child spent in active pursuits or pursuits that restricted movement. With increasing age, children generally spent more time in active pursuits and watching television, and less time in situations that restrict movement. Associations were found with age of developmental milestone attainment but not sex or maternal education. Stability over time was strongest for television viewing (β = 0.34–0.38) and time spent outdoors (β = 0.27–0.33). Contrary to guidelines, television viewing increased and showed stability, suggesting a need to target this behaviour very early in life to achieve optimal longer term outcomes.

Three-year follow-up of physical activity in Norwegian youth from two ethnic groups: associations with socio-demographic factors

BackgroundMore research on factors associated with physical activity and the decline in participation during adolescence is needed. In this paper, we investigate the levels, change, and stability of physical activity during the late teens among ethnic Norwegians and ethnic minorities, and we examine the associations between physical activity and socio-demographic factors.MethodsThe baseline (T1) of this longitudinal study included 10th graders who participated in the youth part of the Oslo Health Study, which was carried out in schools in 2000–2001. The follow-up (T2) in 2003–2004 was conducted partly at school and partly by mail. A total of 2489 (1112 boys and 1377 girls) participated both at baseline and at follow-up. Physical activity level was measured by a question on weekly hours of physical activity outside of school. Socio-demographic variables were collected by questionnaire and from data obtained from Statistics Norway. Analysis of variance was used to study the level of and changes (T1 to T2) in physical activity, and the associations between physical activity and socio-demographic factors. Stability in physical activity was defined as the percentage of students reporting the same physical activity both times.ResultsBoys were more active than girls at age 15 and 18 years, independent of ethnic background. Among girls, ethnic Norwegians were more active than ethnic minorities. Hours per week spent on physical activity declined in all groups during the follow-up period. Few associations were found between physical activity and socio-demographic factors in both cross-sectional and longitudinal data. Among the ethnic minority girls, 65% reported being physically active 0–2 hours per week at baseline, and 82% of these girls reported the same level at follow up.ConclusionThe association between physical activity and ethnicity at age 15 years remained the same during the follow-up. Few associations were found between physical activity and socio-demographic variables. A large proportion of ethnic minority girls reported a persistently low physical activity level, and this low participation rate may need special attention.

Stability of Physical Activity across the Lifespan

Physical activity is associated with various health-relevant psychosocial and physiological processes, but activity stability across extended time periods is inadequately understood. This lifespan longitudinal cohort study examined activity levels of 723 males and 554 females. Associations across time were computed and structural equation modeling compared a one factor model and a simplex model. Results showed activity levels are somewhat stable from childhood through middle and late adulthood. Further, a simplex model provided a better fit than a one factor model. Successful models and interventions to improve health will likely require a more nuanced, pattern-sensitive understanding of physical activity across time.

Changes in physical activity in adolescent girls: a latent growth modelling approach

To examine: (1) the developmental trajectory of physical activity as well the influence of body mass index (BMI) and friend support on initial physical activity and change of physical activity; and (2) the stability of physical activity in adolescent girls. Participants were 193 urban adolescent girls and their best friends. Physical activity was measured using the 3-day physical activity recall. Best friend social support was assessed using a questionnaire. BMI was calculated based on height and body mass of the participants. Data were collected on four occasions over a 1.75-year period. The stability coefficients for moderate, vigorous and total physical activity were statistically significant and ranged from 0.25 to 0.62. There was a curvilinear decrease in physical activity and a curvilinear increase in BMI and friend social support across four measurement occasions. Latent growth modelling (LGM) revealed that initially higher level of friend social support was associated with higher physical activity, and higher level of BMI was associated with lower levels of physical activity. With the physical activity change factor, there were statistically significant and positive direct effect from friend social support change factor, and statistically significant and negative direct effect from BMI change factor. Change in friend social support was positively and change in BMI was inversely associated with a change in adolescent girls' physical activity.

Promoting physical activity in older adults by education of home visitors

The objectives were to investigate in older adults (1) whether regular preventive home visits are associated with change or stability in physical activity and (2) whether education of home visitors influences stability and change in physical activity. The design was a prospective controlled randomised follow-up study with randomization at municipality level (17 intervention and 17 control municipalities) and outcomes measured at individual level. Visitors in the intervention-municipalities received regular education during 3years. The effect of the intervention was measured by a questionnaire survey among 1,913 old persons living in the 34 municipalities at baseline and 4½-year follow-up. Changes in physical activity were measured through self-reported frequencies of vigorous physical activity. All logistic regression analyses were stratified by sex and age group (75 and 80years old). There was no effect of receiving preventive home visits on change in physical activity among the men and among the 75-year-old women. Among the physically active 80-year-old women those who accepted and received more than four preventive home visits were more likely to go on being physically active compared to women who did not receive preventive home visits. Among the sedentary 80-year-old women those living in the intervention municipalities tended to increase their physical activity compared to the control women. These results were not seen in the old men. Preventive home visits as part of daily routine in primary care and education of home visitors and general practitioners may promote physical activity in older women.

Short Term Stability of Physical Activity and Sedentary Behaviour using Accelerometery

Short Term Stability of Physical Activity and Sedentary Behaviour using Accelerometery

Stability Of Physical Activity In Children As Assessed By Accelerometry

Stability Of Physical Activity In Children As Assessed By Accelerometry

Stability Of Physical Activity In Children As Assessed By Accelerometry

Accurate estimates of habitual physical activity (PA) are essential when examining the associations between PA and health outcomes. Evidence suggests that a minimum of 4 days of monitoring is required for assessing PA by accelerometry. However, intra-individual variation throughout the year may lead to inaccurate assessments of habitual PA. PURPOSE To estimate intra-individual variation of children's PA over the course of a year using accelerometry. METHODS Children aged 11 to 12 were recruited from a large birth cohort- the Avon Longitudinal Study of Parents and Children (ALSPAC). Children were asked to wear an accelerometer for 7 days and then again on a further 2 occasions in the next two seasons of the year. Accelerometer counts per minute (cpm) were used as the main PA outcome measure. Multilevel modelling was used to estimate the inter- and intra-individual variance in PA. RESULTS 208 children had data for three separate occasions throughout the year; mean (SD) counts per minute were 601 (179), 611 (189) and 600 (191) for the first occasion (Sep 2003 to Jan 2004), second occasion (Jan to July 2004) and third occasion (March to Sep 2004) respectively. Defining seasons as December to February, March to May, June to August, and September to November, the mean (SD) counts per minute were 524 (148), 641 (203), 583 (178) and 614 (196) respectively. A random intercepts model was fitted to separate the inter- and intra-individual variance components of PA, with adjustment for gender. The intra-individual SD was 131 counts per minute, and the coefficient of variation (SD as % of mean counts per minute) was 22%. The intra-class correlation was 0.50. Two sine and cosine functions of the month of data collection were then added to the model as fixed effects, allowing two peaks and troughs throughout the year. The highest counts were in May and October, and the lowest in January and July. The intraindividual variance component was reduced by 4% by inclusion of these terms in the model, and the intra-class correlation increased slightly to 0.52. CONCLUSION This study suggests that intra-individual variance should be considered when accelerometry is used to estimate habitual PA in children. Further work will consider whether this variation is driven by differences in PA between school holidays and term-time. Supported by NIH Grant R01 HL071248-01A1

DETERMINANTS OF PHYSICAL ACTIVITY MAINTENANCE IN COLLEGE STUDENTS

Motivation has been consistently related to physical activity adoption and maintenance. Lee and DiClemente (1999, 2001) found that intrinsic and extrinsic motivation increased significantly by stage of exercise adoption. PURPOSE The purpose of this study was to extend this work by examining changes in motivation and other psychosocial variables as a function of patterns of physical activity maintenance (Bock et al., 2001). METHODS Healthy college students (N=142, 66.2% female; 88.7% Caucasian; age 21.3 ±3.6 yr) enrolled in four exercise (N=72; aerobics, kickboxing, and strength training) and four lecture (N=70; AIDS Awareness, Personal Health, and Human Sexuality) classes completed instruments to measure demographic variables, intrinsic and extrinsic motivation, and other psychosocial factors at the beginning and end of the 10-wk academic quarter. Exercise stage was measured pre and post, and students were classified into Stable Inactive (SI: n=32), Stable Active (SA: n=45), Regressed (RG: n=16), and Progressed (PG: n=20). RESULTS Participants in exercise classes reported stability in physical activity while physical activity among those in lecture classes significantly declined. Those in exercise classes also reported greater intrinsic and extrinsic motivation than did those in lecture classes. After adjusting for class assignment, repeated measures ANOVAs showed that SAs reported more exercise and scored consistently higher on intrinsic motivation, social support and self efficacy than those in SI, RG and PG (p < .05). Self-efficacy for making time for exercise was the only factor that distinguished among maintenance groups over time (p < .05), increasing for PR and decreasing for RG. CONCLUSIONS Factors other than intrinsic and extrinsic motivation may mediate the processes of adoption and maintenance. Commitment and behavioral skills such as time management may be stronger indicators of physical activity maintenance rather than cognitive measures of attitudes or beliefs. Funded in part by the School of Physical Activity and Educational Services, The Ohio State University

Stability of leisure-time physical activity during adolescence--a longitudinal study among 16-, 17- and 18-year-old Finnish youth.

Participation in physical activity during childhood and adolescence is frequently mentioned as one factor likely to promote a more active lifestyle in adulthood with its health benefits. We studied the changes in leisure-time physical activity pattern and self-reported fitness during a three-year period in adolescence and investigated whether the type of sports has an effect on stability of physical activity at leisure. A questionnaire with identical physical activity items was sent to Finnish twins on their 16th and 17th birthdays and 6 months after the 18th birthday. A total of 1338 boys and 1596 girls responded to all three questionnaires, with response rates of 73.6% and 86.5%. The proportions of very active adolescents and adolescents with very good self-reported fitness seem to be alike at each age. Among girls, 23.7% to 27.7% reported being very active (4-5 times a week) and 13.7% to 15.1% considered their physical fitness to be very good at the ages of 16, 17 and 18. Among boys, the comparable percentages were 31.5% to 35.5% and 30.6% to 34.4%. However, the longitudinal three-year follow up showed substantial changes over time among individuals from one physical activity group to another. Only 19.1% of boys and 11.2% of girls were persistent exercisers (i.e., very active on all three years) and 15.6% of boys and 5.1% of girls were persistently fit (i.e., very good self-reported fitness on all three years). Stability of leisure-time physical activity was highest among those who participated in several different types of sports. Among boys the proportion of persistent exercisers was highest for those who participated in cross-country skiing, jogging and body-building (22.0-41.5%) and among girls for those who participated in ball games (11.9-28.6%). Those who participated in organised sports were more often persistent exercisers than those who did not (odds ratio = 13.2 for boys (CI 9.4-18.7) and 8.9 for girls (CI 6.4-12.5)). Also, those who participated in organised sports were more often persistently fit (odds ratio = 7.3 for boys (CI 5.2-10.2) and 10.4 for girls (CI 6.4-16.9). Adolescents are recommended to participate in and try different types of sports, and especially for girls ball games would appear to favour long-term maintenance of leisure-time physical activity.

Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study

The stability of physical fitness and physical activity in Flemish males from 18 to 40 years of age was investigated. In addition, effects of a consistently low-activity or high-activity level during the same age period on physical fitness were studied. The sample consisted of males who were followed longitudinally from age 13 to age 18 years, and were remeasured at the ages of 30, 35, and 40 years. Complete data about physical fitness and physical activity between 13 and 40 years were available for 130 subjects. Stability was measured using Pearson autocorrelations and simplex models. Multivariate analysis of variance (MANOVA) for repeated measurements was used to look for the effects of activity level on physical fitness. Simplex models showed higher stability coefficients than Pearson correlations, and stability of physical fitness was higher than stability of physical activity. Physical fitness showed the highest stability in flexibility (r = 0.91 between 18 and 30 years, r = 0.96 for both the 30–35 and 35–40 ages intervals), while physical activity showed the highest stability during work (r between 0.70 and 0.98 for the 5-year intervals). Results from MANOVA indicated that for some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than assumed and, therefore, it is a useful and independent indicator for further research. Although possible confounding factors are present (e.g., heredity), a higher level of physical activity during work and leisure time on a regular basis benefits physical fitness considerably. Am. J. Hum. Biol. 12:487–497, 2000. © 2000 Wiley-Liss, Inc.

Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study.

The stability of physical fitness and physical activity in Flemish males from 18 to 40 years of age was investigated. In addition, effects of a consistently low-activity or high-activity level during the same age period on physical fitness were studied. The sample consisted of males who were followed longitudinally from age 13 to age 18 years, and were remeasured at the ages of 30, 35, and 40 years. Complete data about physical fitness and physical activity between 13 and 40 years were available for 130 subjects. Stability was measured using Pearson autocorrelations and simplex models. Multivariate analysis of variance (MANOVA) for repeated measurements was used to look for the effects of activity level on physical fitness. Simplex models showed higher stability coefficients than Pearson correlations, and stability of physical fitness was higher than stability of physical activity. Physical fitness showed the highest stability in flexibility (r = 0.91 between 18 and 30 years, r = 0.96 for both the 30-35 and 35-40 ages intervals), while physical activity showed the highest stability during work (r between 0.70 and 0.98 for the 5-year intervals). Results from MANOVA indicated that for some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than assumed and, therefore, it is a useful and independent indicator for further research. Although possible confounding factors are present (e.g., heredity), a higher level of physical activity during work and leisure time on a regular basis benefits physical fitness considerably. Am. J. Hum. Biol. 12:487-497, 2000. Copyright 2000 Wiley-Liss, Inc.

Reproducibility and Stability of Physical Activity in Children

The purpose of this study was to examine the between-day reproducibility of physical activity across 1 week and determine the stability of physical activity over 2 years. Forty-two children (19 boys, 23 girls) aged 8–9 years at the beginning of the study were followed across 1 week and over a 2-year period. Physical activity was assessed by Caltrac accelerometer. Reproducibility and stability of physical activity was analyzed using Spearman correlations. The results revealed significant Spearman rank order correlations between weekdays (r = 0.64 to 0.79) and weekend days (r = 0.53 to 0.67). Spearman rank order correlations between weekdays and weekend days during two monitoring sessions were consistently lower, ranging from 0.34 to 0.57. It was concluded that the between-day reproducibility of accelerometer monitoring was higher between similar days of the week (weekdays or weekend days). Shortterm stability of physical activity during late childhood was moderate.