Changes In Moderate-to-vigorous Physical Activity Research Articles

Moderating Effects of Health Literacy on Change in Physical Activity Among Latinas in a Randomized Trial.

Latinas report low rates of physical activity (PA) and are at risk for poor health outcomes. Language and literacy barriers impede access and utilization of PA-related resources. This study examined health literacy as a moderator on changes in moderate-to-vigorous physical activity (MVPA) in 196 Latinas enrolled in Seamos Saludables, a randomized-controlled trial of a 6-month culturally and linguistically adapted PA print intervention Secondary analyses were conducted on demographics, acculturation and generation status, and health literacy (Newest Vital Sign). MVPA was determined by 7 day physical activity recall, assessed at baseline and 6 months. General linear models examined interaction effects between health literacy (HL), experimental condition (treatment vs. control), and generation status. Health literacy moderated change in MVPA from baseline to 6 months. The intervention effect was greater among first-generation Latinas with limited health literacy. Differences in health literacy level appear to influence MVPA outcomes. Formative research is recommended to ensure that materials are appropriate when developing print-based PA interventions, particularly among first-generation Latinas who are more likely to have limited health literacy.

Validity of the global physical activity questionnaire (GPAQ) in assessing levels and change in moderate-vigorous physical activity and sedentary behaviour.

BackgroundFeasible, cost-effective instruments are required for the surveillance of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) and to assess the effects of interventions. However, the evidence base for the validity and reliability of the World Health Organisation-endorsed Global Physical Activity Questionnaire (GPAQ) is limited. We aimed to assess the validity of the GPAQ, compared to accelerometer data in measuring and assessing change in MVPA and SB.MethodsParticipants (n = 101) were selected randomly from an on-going research study, stratified by level of physical activity (low, moderate or highly active, based on the GPAQ) and sex. Participants wore an accelerometer (Actigraph GT3X) for seven days and completed a GPAQ on Day 7. This protocol was repeated for a random sub-sample at a second time point, 3–6 months later. Analysis involved Wilcoxon-signed rank tests for differences in measures, Bland-Altman analysis for the agreement between measures for median MVPA and SB mins/day, and Spearman’s rho coefficient for criterion validity and extent of change.Results95 participants completed baseline measurements (44 females, 51 males; mean age 44 years, (SD 14); measurements of change were calculated for 41 (21 females, 20 males; mean age 46 years, (SD 14). There was moderate agreement between GPAQ and accelerometer for MVPA mins/day (r = 0.48) and poor agreement for SB (r = 0.19). The absolute mean difference (self-report minus accelerometer) for MVPA was −0.8 mins/day and 348.7 mins/day for SB; and negative bias was found to exist, with those people who were more physically active over-reporting their level of MVPA: those who were more sedentary were less likely to under-report their level of SB. Results for agreement in change over time showed moderate correlation (r = 0.52, p = 0.12) for MVPA and poor correlation for SB (r = −0.024, p = 0.916).ConclusionsLevels of agreement with objective measurements indicate the GPAQ is a valid measure of MVPA and change in MVPA but is a less valid measure of current levels and change in SB. Thus, GPAQ appears to be an appropriate measure for assessing the effectiveness of interventions to promote MVPA.

A Daily Process Analysis of Intentions and Physical Activity in College Students

Social-cognitive theories, such as the theory of planned behavior, posit intentions as proximal influences on physical activity (PA). This paper extends those theories by examining within-person variation in intentions and moderate-to-vigorous physical activity (MVPA) as a function of the unfolding constraints in people's daily lives (e.g., perceived time availability, fatigue, soreness, weather, overeating). College students (N = 63) completed a 14-day diary study over the Internet that rated daily motivation, contextual constraints, and MVPA. Key findings from multilevel analyses were that (1) between-person differences represented 46% and 33% of the variability in daily MVPA intentions and behavior, respectively; (2) attitudes, injunctive norms, self-efficacy, perceptions of limited time availability, and weekend status predicted daily changes in intention strength; and (3) daily changes in intentions, perceptions of limited time availability, and weekend status predicted day-to-day changes in MVPA. Embedding future motivation and PA research in the context of people's daily lives will advance understanding of individual PA change processes.

School-Day and Overall Physical Activity Among Youth

Increasing school-day physical activity through policy and programs is commonly suggested to prevent obesity and improve overall child health. However, strategies that focus on school-day physical activity may not increase total physical activity if youth compensate by reducing physical activity outside of school. Objectively measured, nationally representative physical activity data were used to test the hypothesis that higher school-day physical activity is associated with higher overall daily physical activity in youth. Accelerometer data from 2003-2004/2005-2006 National Health and Nutrition Examination Surveys were analyzed in 2012 to estimate physical activity levels during the school day (8AM-3PM) among youth aged 6-19 years (n=2548). Fixed-effects regressions were used to estimate the impact of changes in school-day minutes of moderate-to-vigorous physical activity (MVPA) on changes in total daily MVPA. Each additional minute of school-day MVPA was associated with an additional 1.14 minutes (95% CI=1.04, 1.24; p<0.001) of total daily MVPA, or 0.14 additional minutes (95% CI=0.04, 0.24; p=0.008) outside the school day, controlling for total daily accelerometer wear time and age, gender, race/ethnicity, and other non-time varying covariates. There were no differences in the effect of school-day MVPA on total MVPA by age group, gender, race/ethnicity, poverty status, or degree of change in MVPA. Higher school-day MVPA was associated with higher daily MVPA among U.S. youth with no evidence for same-day "compensation." Increasing school-based physical activity is a promising approach that can improve total daily physical activity levels of youth.

Longitudinal Relationship of Physical Activity With Insulin Sensitivity in Overweight and Obese Pregnant Women

Physical activity (PA) initiated in the second half of pregnancy does not affect (or modify) insulin sensitivity in normal weight women. However, this might be different in obese women with lower insulin sensitivity. To test the hypothesis that in overweight and obese women at risk for gestational diabetes, PA is related to improved maternal glucose and insulin metabolism in pregnancy. A longitudinal study, with measurements at 15, 24, and 32 weeks of gestation, was conducted. Time spent in moderate-to-vigorous PA (MVPA) was measured objectively. In regression models, the relationship between time spent in MVPA at week 15 and changes in MVPA from 15 weeks to 24 or 32 weeks with fasting glucose, glycosylated hemoglobin, fasting insulin, insulin sensitivity, and insulin response at week 24 or 32 was assessed. In a group of 24 women, MVPA in early pregnancy was significantly associated with a reduced first- and second-phase insulin response at week 32. Women with larger decreases in MVPA throughout pregnancy had significantly higher fasting insulin levels, worse insulin sensitivity, increased first- and second-phase insulin response, and higher triglyceride levels in late pregnancy compared to women with smaller decreases in MVPA. Time spent in MVPA was not related to glucose or glycosylated hemoglobin levels. In our group of overweight and obese pregnant women, MVPA was associated with improved insulin sensitivity, insulin response, and decreased triglycerides at 32 weeks of pregnancy. This supports efforts for counseling obese women at risk for gestational diabetes in pregnancy to maintain their MVPA levels.

Cognitive‐behavioural physical activity treatment in African‐American pre‐schoolers: Effects of age, sex, and BMI

Prevalence of overweight and obesity in children of 5 years and younger has greatly increased in countries including Australia, Canada, the UK and the USA, with African-Americans most affected in the USA. Low amounts of physical activity may be a primary cause. Interventions intended to increase physical activity during pre-school have had minimal effects. A physical activity intervention derived from self-efficacy and social cognitive theory administered by pre-school teachers in the USA (Start For Life) was contrasted with typical care over 8 weeks. The 30-min-per-day treatment incorporated structured gross motor skill physical activities and training in self-management and self-regulation skills. The African-American children in the treatment (n = 154, 21 classrooms) and control (n = 121, 11 classrooms) groups ranged in age from 3.5 to 5.6 years. Mixed-model repeated measures analysis of variances indicated significantly (P ≤ 0.05) greater increases in moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) in the treatment group when both the children and classrooms were the unit of analysis. Time in sedentary activities was not affected. Together, age, sex and body mass index (BMI) percentile significantly predicted treatment-related changes in MVPA (R(2) = 0.11) and VPA (R(2) = 0.11), with age (β = -0.22 and β = -0.23, respectively) and BMI percentile (β = -0.24 and β = -0.23, respectively) contributing uniquely to the explained variances indicating greater treatment effects for participants who were younger and had a lower BMI percentile. The Start For Life treatment was associated with increased MVPA by approximately 1 h per week, with most of that change being in VPA. After sufficient replication, adjustments may be made to maximise treatment effects.

Social cognitive mediators of the effect of the MobileMums intervention on physical activity.

To explore whether improvements in physical activity following the MobileMums intervention were mediated by changes in Social Cognitive Theory (SCT) constructs targeted in the intervention (barrier self efficacy, goal setting skills, outcome expectancy, social support, and perceived environmental opportunity for exercise). This paper also examined if the mediating constructs differed between initial (baseline to 6 weeks) and overall (baseline to 13 weeks) changes in physical activity. Secondary analysis of data from a randomized controlled trial involving 88 postnatal women (<12 months postpartum). Participants were randomized to receive either the 12-week MobileMums intervention or a minimal-contact control condition. Physical activity and proposed mediators were assessed by self-report at baseline, 6 weeks, and 13 weeks. Walking for Exercise frequency was assessed using the Australian Women's Activity Survey and frequency of moderate-to-vigorous physical activity (MVPA) was assessed using a single-item question. Initial improvements in goal-setting skills mediated the relationship between experimental condition and initial changes in MVPA, αβ (95% CI) = 0.23(0.01, 0.59), and Walking for Exercise, αβ (95% CI) = 0.34(0.06, 0.73). Initial improvements in barrier self efficacy mediated the relationship between experimental condition and initial change in MVPA, αβ (95% CI) = 0.36(0.12, 0.65), but not Walking for Exercise. None of the SCT outcomes significantly mediated the relationship between experimental condition and overall (baseline to 13 weeks) change in frequency of MVPA or Walking for Exercise. Future interventions with postnatal women using SCT should target barrier self-efficacy and goal setting skills in order to increase physical activity.

Use of SPARK to Promote After‐School Physical Activity

The after-school period is potentially an important venue for increasing physical activity for youth. We sought to assess the effectiveness of the Sports, Play, and Recreation for Youth (SPARK) program to increase physical activity and improve cardiorespiratory fitness and weight status among elementary students after school. This quasi-experimental controlled study compared change in moderate to vigorous physical activity (MVPA), body mass index (BMI) z-score, and cardiorespiratory fitness (VO(2) ) over 5 months between students in after-school programs exposed to SPARK versus controls. Participants were fifth grade students at 3 intervention schools (N = 48) and 3 control schools (N = 52). There was no difference between groups in mean change in MVPA, BMI z-score, or cardiorespiratory fitness. After-school time dedicated to physical activity did not increase with the implementation of SPARK. Intervention students' self-assessment of their activity levels relative to their peers significantly increased compared to control students (p = .011). In this 5-month study, the SPARK program did not increase MVPA in the after-school setting. Increasing the amount of time dedicated to physical activity may be as important as the curriculum used to effectively increase physical activity after school.

A Short-Term Physical Activity Randomized Trial in the Lower Mississippi Delta

BackgroundThe purpose of this study was to determine if a short-term pedometer-based intervention results in immediate increases in time spent in moderate-to-vigorous physical activity (MVPA) compared to a minimal educational intervention.MethodsA sample of 43 overweight adults 35 to 64 years of age participated in a one week pedometer-based feasibility trial monitored by accelerometry. Participants were randomized into a one-week education-only group or a group that also wore a pedometer. Accelerometer-measured MVPA was measured over 7 days at baseline and again for 7 days immediately post-intervention.ResultsMinutes of MVPA increased significantly in the overall sample (p = 0.02); however, the effect of adding the pedometer to the education program was not significant (p = 0.89). Mean (±SE) MVPA increased from 12.7±2.4 min/day to 16.2±3.6 min/day in the education-only group and from 13.2±3.3 min/day to 16.3±3.9 min/day in the education+pedometer group. The correlation between change in steps/day and change in MVPA was 0.69 (p<0.0001).ConclusionsThe results of this study suggest that the addition of a pedometer to a short-term education program does not produce added benefits with respect to increasing physical activity in the Lower Mississippi Delta.Trial RegistrationClinicalTrials.gov NCT01264757

Increasing Moderate-to-Vigorous Physical Activity in the Lower Mississippi Delta

PURPOSE: To determine if a short-term pedometer-based educational intervention results in immediate increases in time spent in moderate-to-vigorous physical activity (MVPA) compared to an education-only intervention, and whether increases in the number of steps taken per day correlate with measurable increases in MVPA. METHODS: This was a randomized, controlled short-term (one week) pedometer-based feasibility trial evaluated by accelerometry. Primary outcomes were changes in time spent in accelerometer-determined MVPA. All assessments were conducted at baseline (pre-intervention) and immediately post-intervention. The sample included 42 overweight adults 35 to 64 years of age from a small community in the Louisiana Lower Mississippi Delta region. Participants were randomized equally into a one-week education-only control group or a group that received the same education and wore a pedometer. Repeated measures ANOVA was used to compare group changes in 7-day accelerometer-measured MVPA from baseline to post-intervention. Pearson correlation was used to assess the association between changes in steps taken per day and changes in time spent in MVPA. RESULTS: There was an overall increase in MVPA in the entire sample (p=0.02); however, the effect of the addition of the pedometer to the education program itself was not significant (p=0.89). Mean (±SE) MVPA increased from 12.7±2.4 min/day to 16.2±3.6 min/day in the education-only group and from 13.2±3.3 min/day to 16.3±3.9 min/day in the education + pedometer group. The correlation between changes in steps/day and changes in MVPA was 0.69 (p<0.0001) in the overall sample, 0.72 (p = 0.0003) in the education-only group and 0.63 (p = 0.004) in the education + pedometer group. CONCLUSIONS: The addition of a pedometer to a short-term education program did not produce increases in MVPA beyond that observed with an education program alone in this Lower Mississippi Delta sample. However, participants who did increase their walking behavior had a propensity to also increase their time spent in MVPA. Supported by ARS/USDA Cooperative Agreement no. 58-6251-8-038.

Effects of Child Care Policy and Environment on Physical Activity

Child care centers differ systematically with respect to the quality and quantity of physical activity they provide, suggesting that center-level policies and practices, as well as the center's physical environment, are important influences on children's physical activity behavior. To summarize and critically evaluate the extant peer-reviewed literature on the influence of child care policy and environment on physical activity in preschool-aged children. A computer database search identified seven relevant studies that were categorized into three broad areas: cross-sectional studies investigating the impact of selected center-level policies and practices on moderate-to-vigorous physical activity (MVPA), studies correlating specific attributes of the outdoor play environment with the level and intensity of MVPA, and studies in which a specific center-level policy or environmental attribute was experimentally manipulated and evaluated for changes in MVPA. Staff education and training, as well as staff behavior on the playground, seem to be salient influences on MVPA in preschoolers. Lower playground density (less children per square meter) and the presence of vegetation and open play areas also seem to be positive influences on MVPA. However, not all studies found these attributes to be significant. The availability and quality of portable play equipment, not the amount or type of fixed play equipment, significantly influenced MVPA levels. Emerging evidence suggests that several policy and environmental factors contribute to the marked between-center variability in physical activity and sedentary behavior. Intervention studies targeting these factors are thus warranted.

The relative influence of demographic, individual, social, and environmental factors on physical activity among boys and girls.

BackgroundThis study aimed to evaluate the associations of selected demographic, individual, social, and environmental factors with moderate-to-vigorous physical activity (MVPA) in a sample of children and adolescents.MethodsMVPA was assessed among youth (n = 294) 10-17-years-old using the ActiGraph accelerometer. Youth completed measures of demographic and individual variables related to physical activity (PA), perceived social support by parents and peers, and perceived neighborhood characteristics. Parents completed the long-form of the International Physical Activity Questionnaire. The Physical Activity and Media Inventory was used to measure the home environment and Geographical Information Systems software was used to measure the physical neighborhood environment. Bivariate correlations and hierarchical multiple regression were conducted stratified by gender.ResultsBoys participated in significantly more MVPA than girls. In hierarchical analyses, peer support, home PA equipment, and temperature were significantly associated with MVPA among boys whereas distance to the school they attended was associated with MVPA among girls. The final models accounted for 25% and 15% of the variance in MVPA among boys and girls, respectively.ConclusionsImportant differences exist among the individual, social, and environmental factors related to MVPA between boys and girls. Boys' levels of activity appear to be influenced by factors closely linked to unstructured and social types of activities whereas girls' activities relate to internal and external barriers as well as their proximity to their schools. The prospective contribution of these important individual, social, and environmental factors to changes in MVPA among children and adolescents remains to be determined.

Does Participation in Organized Sports Predict Future Physical Activity for Adolescents from Diverse Economic Backgrounds?

Purpose To examine cross-sectional and longitudinal associations between socioeconomic status (SES), gender, sports participation and moderate-to-vigorous physical activity (MVPA) in adolescents. Methods Project EAT (Eating Among Teens), a population-based longitudinal study followed a socioeconomically and ethnically diverse sample of 1709 adolescents in 1998–1999 (Time 1) and 2003–2004 (Time 2). Mixed model regression analyses were used to examine longitudinal trends in MVPA as a function of SES and previous sports involvement. Results For both genders, participation in organized sports and weekly hours of MVPA were positively associated with SES. On average, MVPA decreased between high school and young adulthood for both genders. Adolescents who participated in sports during high school showed a steeper decline in weekly hours of MVPA than their non–sports-participating counterparts. SES had a significant moderating effect on the change in MVPA over time for boys who participated in organized sports, with low SES boys showing a steeper decline in MVPA between time periods than higher SES boys. Although on average, a statistically significant difference in MVPA between previous sports participants and nonparticipants remained at Time 2, for all SES groups and both genders, the gap between hours of MVPA was either overcome or significantly narrowed by young adulthood. Conclusions Increased dependence on organized sports for MVPA may be insufficient to meet the needs of youth following high school, especially for low SES youth. Designing physical activity promotions that reach and address the unique needs of lower SES youth and families is a public health priority.

Physical activity as a strategy for maintaining tobacco abstinence: A randomized trial

Objectives For smoking cessation, physical activity (PA) may help manage withdrawal symptoms, mood, stress, and weight; yet studies of PA as an aid for smoking cessation have been mixed. This study examined: (1) the impact of an extended relapse prevention program on increasing moderate to vigorous PA (MVPA) in adults enrolled in a tobacco cessation treatment trial; (2) whether changes in MVPA were associated with sustained abstinence from smoking; and (3) mechanisms by which MVPA may support sustained abstinence from smoking. Methods In a randomized controlled trial conducted from 2003–2006 in San Francisco, California, 407 adult smokers received a 12 week group-based smoking cessation treatment with bupropion and nicotine patch with the quit date set at week 3. At week 12, participants were randomized to no further treatment or to 40 weeks of bupropion or placebo with or without an 11-session relapse prevention intervention of which 2 sessions (held at weeks 16 and 20) focused on PA. Participants receiving the PA intervention ( n = 163) received a pedometer, counseling to increase steps 10% biweekly towards a 10,000 steps/day goal, and personalized reports graphing progress with individualized goals. The International Physical Activity Questionnaire assessed weekly minutes of MVPA at baseline and weeks 12 and 24. Sustained abstinence from tobacco at week 24 was validated with expired carbon monoxide. Results In a repeated mixed model analysis, intervention participants significantly increased their MVPA relative to control participants, F(1,475) = 3.95, p = .047. Pedometer step counts also increased significantly, t(23) = 2.36, p = .027, though only 15% of intervention participants provided 6 weeks of pedometer monitoring. Controlling for treatment condition, increased MVPA predicted sustained smoking abstinence at week 24, odds ratio = 1.84 (95% CI: 1.07, 3.05). Among participants with sustained abstinence, increased MVPA was associated with increased vigor ( r = 0.23, p = .025) and decreased perceived difficulty with staying smoke-free ( r = − 0.21, p = .038). Conclusion PA promotion as an adjunct to tobacco treatment increases MVPA levels; changes in MVPA predict sustained abstinence, perhaps by improving mood and self-efficacy.

PREDICTORS OF CHANGE IN ADOLESCENT PHYSICAL ACTIVITY

A 4 year, prospective study was undertaken to identify predictors of change in physical activity during adolescence. The sample consisted of 238 teens, including 161 Mexican-American and 62 non-Hispanic White teens, 135 girls and 103 boys. Each year, study participants completed a physical activity questionnaire and responded to items concerning the following predictor variables: self-efficacy, perceived barriers, personal incentives and social support for activity, adequacy, enjoyment, and predilection for physical activity. Changes in moderate to vigorous physical activity (MVPA) and in predictor variables were represented by residualized change scores. Multiple regression analysis using the residualized changes in predictor variables revealed that only the perception that a boyfriend or girlfriend kept participants from being active was significantly associated with change in MVPA, accounting for 2.1% of the variance. Regression using baseline values of the predictor variables revealed that parental & peer support for, adequacy in, and predilection for activity were significantly associated with change in MVPA, accounting for 20.5% of the variance. These results suggest possible strategies for resisting the decline in physical activity during adolescence.