Physical Activity Recall Research Articles

Abstract 139: Middle School-based Intervention Leads to Improved Behaviors: A Report from Project Healthy Schools

Background: Project Healthy Schools (PHS) provides environmental changes and in-class lessons to sixth grade students to reduce future cardiovascular and diabetes risk. PHS has 5 main goals: (1) decrease mindless screen time, (2) exercise 150 minutes/week, (3) decrease unhealthy beverages, (4) increase fruits and vegetables and (5) decrease fried, fatty and sweet foods. Previous research demonstrated the program’s impact on total cholesterol, low density lipoprotein, and blood pressure. Methods: Baseline and follow up behavioral survey data was collected from 2130 sixth grade students, including: 24-hour food and 7-day physical activity recalls; compared using non-parametric Wilcoxon signed rank test. The behaviors were defined as follows: “screen time” as hours/week on computers, video games or TVs not for school; “exercise” as sessions/week of moderate for 30 minutes, vigorous for 20 minutes; servings of “unhealthy beverages” as soda, sports drinks or punch (not juice); “fruits and vegetables” as any fruits or vegetables (not fries, chips or juice) and “fried, fatty and sweet food” as any fried meat, hamburger, hot dogs, sausage, bacon, ribs, fries, chips, baked goods or candy. Results: Students improved on follow-up in 3 of 5 goals: decrease screen time (p≤.001), increase exercise (p=0.02) and decrease fried, fatty and sweet foods (p≤.001). Fruits, vegetables and beverages showed almost no net change. Conclusions: Improvements in 3 of 5 goals combined with previous physiologic findings suggest the program is effectively teaching healthy behaviors, but further research is required to improve all lessons, especially those including fruits, vegetables and beverages.

Self‐report use‐of‐time tools for the assessment of physical activity and sedentary behaviour in young people: systematic review

Regular physical activity and limiting extended periods of sitting are two behaviours critical for the prevention of obesity in young people. The purpose of the systematic review was to synthesize the psychometric evidence for self-report use-of-time tools that assess these behaviours. Articles were retrieved that reported reliability and/or validity for use-of-time tools in participants aged 18 years or under. Outcome variables were physical activity, sedentary behaviour and energy expenditure. Study quality was appraised, and the results summarized narratively. Sixteen studies and six different tools were identified. The tools were the Previous Day Physical Activity Recall, the Three-Day Physical Activity Recall, the Physical Activity Interview, the Computerized Activity Recall, the Activitygram, and the Multimedia Activity Recall for Children and Adolescents. Overall, tools indicated moderate validity compared with objective and criterion comparison methods. Generally, validity correlation coefficients were in the range of 0.30-0.40. Correlation coefficients for test-retest reliability ranged widely from 0.24 to 0.98. Use-of-time tools have indicated moderate reliability and validity for the assessment of physical activity and energy expenditure. Future research should focus on using criterion methods and on validating specifically for sedentary behaviour outcomes. Implementation of these tools for population surveillance should be considered.

Does physical activity counselling enhance the effects of a pedometer-based intervention over the long-term: 12-month findings from the Walking for Wellbeing in the west study

BackgroundPedometers provide a simple, cost effective means of motivating individuals to increase walking yet few studies have considered if short term changes in walking behaviour can be maintained in the long-term. The role of physical activity consultations in such interventions is unclear. The purpose of this study was to assess the sustainability of pedometer-based interventions and empirically examine the role of physical activity consultations using long-term results of a community-based walking study.Methods79 low active Scottish men and women (63 women and 16 men) from the Walking for Wellbeing in the West intervention study were randomly assigned to receive either: Group 1; pedometer-based walking programme plus physical activity consultations or Group 2; pedometer-based walking programme and minimal advice. Step counts (Omron HJ-109E Step-O-Meter pedometer), 7 day recall of physical activity (IPAQ long), mood (PANAS) and quality of life (EuroQol EQ-5D) were assessed pre-intervention and 12, 24 and 48 weeks after receiving the intervention. Body mass, body mass index and waist and hip circumference were assessed pre-intervention and 12 and 24 weeks after receiving the intervention. Analyses were performed on an intention to treat basis (baseline value carried forward for missing data) using mixed-factorial ANOVAs and follow-up t-tests.ResultsA significant main effect of time (p < 0.001) was found for step-counts attributable to significant increases in steps/day between: pre-intervention (M = 6941, SD = 3047) and 12 weeks (M = 9327, SD = 4136), t(78) = - 6.52, p < 0.001, d = 0.66; pre-intervention and 24 weeks (M = 8804, SD = 4145), t(78) = - 4.82, p < 0.001, d = 0.52; and pre-intervention and 48 weeks (M = 8450, SD = 3855), t(78) = - 4.15, p < 0.001, d = 0.44. Significant effects were found for several variables of self-reported physical activity, mood and quality of life and are discussed. No other significant effects in health related outcomes were found.ConclusionBoth interventions successfully increased and maintained step counts over 12 months. Physical activity consultations may encourage individuals to be active in other ways beyond walking and to reduce sitting time.Trial Registration NumberCurrent Controlled Trials Ltd ISRCTN88907382

Abstract P264: Meeting 2008 Physical Activity Guidelines for Americans Reduces Risk of Recurrent CVD Events in MI Survivors: The Western New York Acute MI Study (1996–2006)

Introduction: The 2008 Physical Activity Guidelines for Americans (PAG) recommend adults perform at least 150 minutes/week of moderate intensity physical activity or 75 minutes/week of vigorous intensity activity or an equivalent combination of both in order to obtain important health benefits, including lower CHD risk. Despite advances in clinical medicine, survivors of MI remain at substantial risk of recurrent cardiovascular events and death. The aim of our prospective study was to examine whether meeting the PAG reduced risk of recurrent CVD events in MI patients. Hypothesis: We hypothesized that MI survivors who met the current PAG had a more favorable prognosis than those who did not meet the guidelines. Methods: Incident MI cases (933 men, 354 women, 35–69 years old) recruited from 12 of 15 Western NY hospitals completed an interviewer-administered survey and clinic exam. Physical activity (PA) in the previous seven days was assessed using the Stanford 7-day PA recall. Minutes reported in moderate and vigorous intensity recreational, household and occupational activity (MVPA) were summed and participants were categorized as follows (min/week): inactive (0), insufficiently active (&gt;0–&lt;150), met (150–300), and exceeded the guideline goal (&gt;300). Participant surveys, medical records and a search of the National Death Index Plus were used to determine fatal and non-fatal recurrent CVD (ICD9 390–450) events. Cox regression analysis adjusting for age (in years), gender, education (in years), race, BMI, smoking status, hypertension and use of diabetes and lipid medication was conducted to examine the association between PA and recurrent events. Results: During a mean follow up of 4.1 years, 301 recurrent CVD events occurred. At baseline, 174 (13.5%) participants reported no MVPA, 216 (16.8%) were insufficiently active, whereas 259 (20.1%) met and 638 (49.6%) exceeded the PAG, respectively. Multivariate adjusted hazard ratios (95% CI) for recurrent CVD events were Inactive [Ref (1.00)], insufficiently active [0.68 (0.46–1.01)], met [0.63 (0.43–0.92)], and exceeded the guideline goal [0.63 (0.45–0.87)], p-trend =0.019. Conclusion: In this prospective population-based study, there is evidence to support that meeting the 2008 Physical Activity Guidelines for Americans has significant benefits on fatal and non-fatal recurrent CVD events in men and women following myocardial infarction.

A Cluster Analysis of Physical Activity and Sedentary Behavior Patterns in Middle School Girls

To identify similar patterns of physical activity (PA) and sedentary behavior in sixth-grade girls using cluster analysis; to determine which clusters of girls were associated with greater daily minutes of objectively measured PA; and to examine whether girls in these clusters experienced change in PA from sixth to eighth grade. An adventitious cohort of girls (n = 957) from the Trial of Activity for Adolescent Girls were measured at sixth and eighth grade. Activities were identified using the 3-day physical activity recall and a self-report survey and used to create clusters of sixth-grade girls who had similar PA/sedentary behaviors. Accelerometry was used to assess PA in sixth and eighth grade. Data analysis consisted of FASTCLUS procedure and mixed model repeated measures analyses in SAS statistical software. Cluster analysis yielded six clusters (C1: educational sedentary; C2: sports and play; C3: organized sports teams/classes/lessons in past year; C4: active transport and chores; C5: electronic media; C6: sleep). Sixth-grade girls in C2 and C3 had greater average daily minutes of moderate-to-vigorous physical activity (MVPA), metabolic equivalent of a physical activity-weighted MVPA, and vigorous physical activity compared with other clusters (p < .05). In eighth grade, sedentary time increased and PA declined among girls in all clusters (p < .05). Girls in C2 had the greatest decline in PA, whereas girls' PA in C3 declined less. Encouraging participation in organized sports teams/class/lessons in middle school girls may promote greater MVPA and vigorous physical activity than other activities and may help to better sustain PA levels over time.

Evaluation of the Trackstick™ Super GPS Tracker for Use in Walking Research

The recent interest in promoting active commuting necessitates an accurate and feasible method to measure ambulatory physical activity and track routes, for sound evaluation of these interventions. Previous studies used basic measures such as hands up surveys, travel diaries, questionnaires, and physical activity recall (Boarnet, Anderson, Day, McMillan, & Alfonzo, 2005). However, these measures are Susceptible to social desirability and may result in misreported activity levels (Corder, Ekelund, Steele, Wareham, & Brage, 2008). Other more objective measures of commuting behavior include pedometers, accelerometers, and Geographic Information Systems-derived shortest routes (e.g., from home to school; Michaud-Thomson, Davidson, & Cuddihy, 2003; Sirard, Riner, McIver, & Pate, 2005; Timperio et al., 2006).

Reliability and Validity Tests of the Leisure Time Physical Activity Questionnaire for People With Spinal Cord Injury

Martin Ginis KA, Phang SH, Latimer AE, Arbour-Nicitopoulos KP. Reliability and validity tests of the Leisure Time Physical Activity Questionnaire for People with Spinal Cord Injury. ObjectiveTo examine the criterion validity and test-retest reliability of the Leisure Time Physical Activity Questionnaire for People with Spinal Cord Injury (LTPAQ-SCI), a brief measure of leisure time physical activity (LTPA) for people with spinal cord injury (SCI). DesignSurvey with a 1-week follow-up. SettingGeneral community. ParticipantsMen and women with SCI (N=103; mean age ± SD, 48.1±12.7y; mean years postinjury ± SD, 17.9±11.9) who used a wheelchair as the primary mode of mobility. InterventionsNot applicable. Main Outcome MeasuresParticipants completed the Physical Activity Recall Assessment for People with SCI (PARA-SCI) and the LTPAQ-SCI. A subset of the participants (n=35) completed the LTPAQ-SCI a second time, 7 days later. ResultsStatistically significant, positive correlations emerged between the LTPAQ-SCI and PARA-SCI measures of mild, moderate, and heavy intensity LTPA as well as total LTPA. All 4 intraclass correlation coefficients were significant across the test-retest period. ConclusionsThis study provides preliminary evidence of the criterion validity and reliability of the LTPAQ-SCI as a brief measure of LTPA performed by people with SCI.

Habitual active transport, TV viewing and weight gain: A four year follow-up study

ObjectivesTo examine the associations of TV viewing time and domain-specific physical activity with weight change; to determine whether domain-specific physical activity moderates the potential association of TV viewing time with weight change. MethodsWe used four-year longitudinal data (baseline: 2003–2004, follow-up: 2007–2008) on 969 adults from selected neighborhoods in Adelaide, Australia (Age: 48.6±10.6years, 61% females). Mixed models examined four-year weight change as the dependent variable, with TV viewing time, habitual transport and past week domain-specific physical activity at baseline as independent variables. ResultsOn average, participants gained 1.6kg over four years. TV viewing time at baseline was positively associated with weight gain at follow-up. Each additional hour of TV viewing was associated with 0.24–0.27kg of extra weight gain. This relationship was not moderated by recent recall of transport, leisure-time, and occupational physical activity, but was moderated by habitual transport: an additional hour of TV viewing time at baseline was significantly associated with an extra weight gain of 0.65kg at follow-up among those who were inactive in everyday transport; TV time was not significantly associated with weight change among those who were regularly active in transport. ConclusionHabitual active transport may protect adults against risk of weight gain associated with prolonged TV viewing time.

Cardiorespiratory fitness and proximity to commercial physical activity facilities among 12th grade girls.

To investigate the relationship between proximity to commercial physical activity (PA) facilities and cardiorespiratory fitness of 12th grade girls. Adolescent girls (n = 786, 60% African American, mean age = 17.6 ± .6 years) performed a submaximal fitness test (Physical Work Capacity 170 test). Commercial PA facilities were mapped and counted within a .75-mile street-network buffer around girls' homes using Geographic Information Systems. Sedentary activities and vigorous physical activity (≥6 metabolic equivalents) were determined by the average number of 30-minute blocks reported per day on the 3-Day Physical Activity Recall. Mixed model regressions were calculated using school as a random variable. Girls had higher weight-relative Physical Work Capacity 170 test scores if there was a commercial PA facility (n = 186, 12.4 ± 4.2 kg m/min/kg) within a .75-mile street-network buffer of home as compared with girls without a nearby facility (n = 600, 11.2 ± 3.6 kg m/min/kg). After adjusting for demographic variables, sports participation, sedentary behaviors, and vigorous physical activity, having one or more commercial PA facilities within a .75-mile street-network buffer of homes was significantly related to cardiorespiratory fitness. Both with and without adjustment for covariates, the presence of a commercial PA facility within a .75-mile street-network buffer of a girl's home was associated with higher cardiorespiratory fitness.

Long-term physical activity outcomes of home-based lifestyle interventions among breast and prostate cancer survivors

Few studies have investigated long-term effects of physical activity (PA) interventions. The goal of this study was to evaluate whether or not increased levels of moderate to vigorous physical activity (MVPA) were maintained by cancer survivors 1 year after receipt of two home-based interventions. The FRESH START trial randomized 543 breast and prostate cancer survivors to 1-of-2 mailed print diet and exercise interventions: sequentially-tailored vs. standardized (attention control). Each arm received eight mailings over a 1-year period, with follow-up at 1 and 2 years. This analysis focuses solely on the 400 participants who had suboptimal levels of MVPA at baseline (measured by the 7-Day Physical Activity Recall) and who completed the 2-year study. Median minutes of MVPA at baseline, 1-year and 2-year follow-up in the tailored intervention arm were as follows: 0, 90, and 60 min/week, respectively. The corresponding values in the attention control group were 0, 30, and 30 min/week. Significant improvements in MVPA from baseline to 2-year follow-up were observed in both study arms (p < 0.01). While significant between-arm differences were observed at 1-year follow-up (p < 0.01), there was only the suggestion of a trend (p = 0.08) at 2-year follow-up. This study provides evidence that mailed-print exercise interventions result in significant and sustainable improvements in MVPA among newly diagnosed cancer survivors that are observed well after the intervention is complete. While tailored interventions, as compared to standardized materials, appear to produce superior improvements in MVPA initially, these differences diminish over time.

Evaluation of 2 self-report measures of physical activity with accelerometry in young adults.

The purpose of this paper is to evaluate self-reported physical activity of young adults using 1-week and 1-year recall measures with an accelerometer as the criterion measure. Participants were a subsample (N = 121, 24 ± 1.7 yrs) from a large longitudinal cohort study. Participants completed a detailed 1-year physical activity recall, wore an accelerometer for 1 week and then completed a brief 1-week physical activity recall when they returned the accelerometer. Mean values for moderate-to-vigorous physical activity (MVPA) from the 3 instruments were 3.2, 2.2, and 13.7 hours/wk for the accelerometer, 1-week recall, and 1-year recall, respectively (all different from each other, P < .001). Spearman correlations for moderate, vigorous, and MVPA between the accelerometer and the 1-week recall (0.30, 0.50, and 0.40, respectively) and the 1-year recall (0.31, 0.42, and 0.44, respectively) demonstrated adequate validity. Both recall instruments may be used for ranking physical activity at the group level. At the individual level, the 1-week recall performed much better in terms of absolute value of physical activity. The 1-year recall overestimated total physical activity but additional research is needed to fully test its validity.

Modeling Errors in Physical Activity Recall Data

Physical activity recall instruments provide an inexpensive method of collecting physical activity patterns on a sample of individuals, but they are subject to systematic and random measurement error. Statistical models can be used to estimate measurement error in activity recalls and provide more accurate estimates of usual activity parameters for a population. We develop a measurement error model for a short-term activity recall that describes the relationship between the recall and an individual's usual activity over a long period of time. The model includes terms for systematic and random measurement errors. To estimate model parameters, the design should include replicate observations of a concurrent activity recall and an objective monitor measurement on a subsample of respondents. We illustrate the approach with preliminary data from the Iowa Physical Activity Measurement Study. In this dataset, recalls tend to overestimate actual activity, and measurement errors greatly increase the variance of recalls relative to the person-to-person variation in usual activity. Statistical adjustments are used to remove bias and extraneous variation in estimating the usual activity distribution. Modeling measurement error in recall data can be used to provide more accurate estimates of long-term activity behavior.

Mediators of physical activity behavior change: Findings from a 12-month randomized controlled trial.

To examine putative mediators of a 12-month motivationally tailored physical activity (PA) promotion intervention. We randomly assigned 239 healthy, underactive adults (moderate-vigorous physical activity <90 min/week; mean age = 47.5 years; 82% women) to receive (a) print-based feedback, (b) phone-based feedback, or (c) contact control. PA at baseline, 6, and 12 months, as measured by the 7-day physical activity recall interview. MEDIATORS: Four TransTheoretical Model constructs explicitly targeted by the intervention (i.e., self-efficacy, decisional balance, cognitive and behavioral processes of change), as well as four additional constructs linked to PA behavior change (i.e., social support, outcome expectancy, PA enjoyment, exercise-induced feelings). Multivariate mediation analyses were used to analyze longitudinal PA outcomes. Changes in behavioral processes and one aspect of exercise-induced feelings (revitalization) satisfied both action theory (i.e., treatment effects on mediators) and conceptual theory (i.e., mediator effects on PA) tests at 6 and 12 months and emerged as statistically significant mediators of treatment effects on PA across delivery channels (ps <.014). Cognitive processes, self-efficacy, decisional balance, and social support for PA participation satisfied Action Theory tests at both 6 and 12 months, but failed conceptual theory tests. Delayed intervention effects were observed on other aspects of exercise-induced feelings, PA enjoyment, and outcome expectancies, but these variables failed mediation testing at 12 months. Findings are consistent with previous research illustrating the importance of behavioral processes of change, but also indicate that affective response to PA may warrant more attention as a potential target of behavior change programs.

Comparison of methods to assess energy expenditure and physical activity in people with spinal cord injury

ObjectiveTo compare different methods of assessing energy expenditure (EE) and physical activity (PA) in people with spinal cord injury (SCI) under community-dwelling conditions.MethodsA reference standard encompassing the doubly labelled water (DLW) technique, heart rate monitoring (FLEX-HR), a multi-sensor armband (SenseWear Armband (SWA)), and two PA recall questionnaires were employed in 14 people with SCI to estimate EE and leisure-time PA.ResultsMean total daily energy expenditure (TDEE) assessed by DLW, FLEX-HR, and SWA were 9817 ± 2491 kJ/day, 8498 ± 1516 kJ/day, and 11414 ± 3242 kJ/day, respectively. Physical activity energy expenditure (PAEE) quantified by DLW was 2841 ± 1626 kJ/day, 2935 ± 1732 kJ/day estimated from FLEX-HR, and 2773 ± 2966 kJ/day derived from SWA. After converting the PA recall questionnaire data to EE in kJ/day, PAEE for the Physical Activity Recall Assessment for People with Spinal Cord Injury (PARA-SCI) was 2339 ± 1171 kJ/day and for Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) 749 ± 1026 kJ/day. DLW-quantified PAEE was moderately associated with PARA-SCI (R2 = 0.62, P < 0.05), but not with the other estimates of PAEE (R2 ranged between 0.13 and 0.30, P > 0.05).ConclusionOur findings revealed that the PARA-SCI recall questionnaire was the best estimate of PAEE compared to the reference standard DLW approach. Although the between-method variability for SWA, FLEX-HR, and PASIPD-derived PAEE was small, there was a weak association between these methods and the criterion DLW technique. The best estimate of DLW-quantified TDEE was by FLEX-HR. SWA significantly overestimated TDEE in this population.

Validity and reliability of a physical activity questionnaire for Vietnamese adolescents

BackgroundAccurate assessment of physical activity in adolescents at population level is necessary. In Vietnam, the International Physical Activity Questionnaire (IPAQ) and Physical Activity Questionnaire for Adolescents (PAQA) have been validated against accelerometers for use in adolescents. However, these questionnaires were originally designed for adults and showed poor validity. This study aims to assess the reliability and validity of the Vietnamese Adolescent Physical Activity Recall Questionnaire (V-APARQ).MethodsOne hundred and sixty five students were recruited from four junior high schools in Ho Chi Minh City Vietnam in 2004. V-APARQ asked students to report their usual organised and non-organised physical activity during a normal week and moderate- (MPA), vigorous- (VPA and moderate-to-vigorous- (MVPA) physical activity were calculated. Reliability was assessed by test-retest (2 weeks apart). Construct validity was assess by 7-day accelerometry, following the completion of the first V-APARQ.ResultsThe construct validity of the V-APARQ showed Spearman correlation of 0.25 and 0.22 for the assessment of the questionnaire when compared to the accelerometer. Test-retest reliability showed a weighted Kappa of 0.75 and the intra-class correlation coefficient for MVPA was 0.57 for the whole group (MPA =0.37 and VPA = 0.62), and were higher in boys than girls. The Bland-Altman plots for reliability show a mean difference of 0.4 minutes (95 % CI = −3.2, 4.0) for daily MVPA (n = 146) and the limits of agreement were −42.6 to 43.4 mins/day. In boys MVPA was lower on the first, compared with second administration of V-APARQ while the reverse was observed among girls.ConclusionThe reliability and validity of the V-APARQ were low to fair, but are comparable to other self-report physical activity questionnaires used among adolescents. V-APARQ will be useful for population monitoring of change in physical activity among urban Vietnamese adolescents.

Sources of Validity Evidence Needed With Self-Report Measures of Physical Activity

Over the years, self-report measures of physical activity (PA) have been employed in applications for which their use was not supported by the validity evidence. To address this concern this paper 1) provided an overview of the sources of validity evidence that can be assessed with self-report measures of PA, 2) discussed the validity evidence needed to support the use of self-report in certain applications, and 3) conducted a case review of the 7-day PA Recall (7-d PAR). This paper discussed 5 sources of validity evidence, those based on: test content; response processes; behavioral stability; relations with other variables; and sensitivity to change. The evidence needed to use self-report measures of PA in epidemiological, surveillance, and intervention studies was presented. These concepts were applied to a case review of the 7-d PAR. The review highlighted the utility of the 7-d PAR to produce valid rankings. Initial support, albeit weaker, for using the 7-d PAR to detect relative change in PA behavior was found. Overall, self-report measures can validly rank PA behavior but they cannot adequately quantify PA. There is a need to improve the accuracy of self-report measures of PA to provide unbiased estimates of PA.

Adaptation and cognitive testing of physical activity measures for use with young, school-aged children and their parents

Increasing physical activity is one way to address the public health concern of childhood obesity. Physical activity measures for use with young, school-aged children are limited. This study adapted two existing activity measures for young children, specifically self-efficacy and 7-day recall of physical activity. Through expert review and cognitive testing, the scales were adapted for use with young, school-aged children (ages 7-9). This article describes how the measures were adapted to insure comprehension of the child self-report measures. Reliability analyses provide support for their use in this population [Cronbach's alpha = 0.76 for the self-efficacy scale; moderate correlation between parent report and child report of child physical activity over the past week (rho = 0.52, P < 0.01]. Suggestions are offered for researchers interested in using similar methods when designing and adapting physical activity measures for new populations.

Trajectories of Physical Activity in Montreal Adolescents From Age 12 to 17 Years

Despite the benefits of physical activity, many Canadian adolescents are inactive and rates of inactivity increase with age. Few studies describe the pattern of change in physical activity as a function of age during adolescence. Data were drawn from the Nicotine Dependence in Teens Study. The analytic sample included 1206 adolescents who completed a 7-day physical activity recall up to 4 times per year over 5 years. Individual growth models, analyzed using multilevel models for change, were developed separately by sex controlling for season. Physical activity levels through adolescence were best described by a cubic function. Levels increased from age 12 to a peak at approximately age 13.5, decreased to age 16.5, and increased again to age 17. Activity participation was highest in the spring and lowest during fall and winter. Substantial within- and between-subject heterogeneity in the trajectories was evident. Adolescent physical activity follows a complex, curvilinear pattern in both males and females, with considerable variation within- and between-persons.

Stanford Seven-Day Physical Activity Recall questionnaire in COPD

Quantification of daily physical activity is of clinical interest in chronic obstructive pulmonary disease (COPD). Objective measures using activity monitors may take several days to obtain reliable results. The aim of our study was to evaluate the Stanford Seven-Day Physical Activity Recall questionnaire (PAR) against the SenseWear armband (SWA) and compare its validity with three other physical activity questionnaires. 43 COPD patients wore the SWA for 7 days. Patients completed the PAR, Baecke, Physical Activity Scale for the Elderly (PASE) and Zutphen questionnaires. Spearman rank correlation, intraclass correlation coefficients (ICC) and receiver-operating characteristics (ROC) curves were used to assess the relationship between the questionnaires and SWA. Assessed by PAR, time spent at ≥3.0 metabolic equivalents (METs) correlated significantly (r=0.54, p<0.001) with equivalent measures from SWA, with an ICC of 0.40. No relationship was seen between the other questionnaires and the SWA. The PAR predicted active patients (≥30 min at ≥3.0 METs or a physical activity level (PAL) ≥1.55) and very inactive patients (PAL <1.40) with an area under ROC curve of 0.83, 0.77 and 0.70, respectively. While the PAR did not measure physical activity sufficiently accurately to make individual recommendations, it was able to identify COPD patients at extremes of the physical activity spectrum, potentially reducing the number of patients requiring direct measurement.

Physical activity fluctuations and body fat during adolescence

The objective of the study was to test the hypothesis that greater fluctuations in physical activity lead to greater increases in body fat during adolescence. Seven hundred fifty-six adolescents in Montreal, Canada, aged 12-13 years at baseline, completed a 7-d physical activity recall questionnaire every 3 months over 5 years. Body mass index (BMI), waist circumference, and triceps and subscapular skinfold thickness were measured at baseline and at the end of follow-up. Subject-specific linear regressions, expressing physical activity as a function of time, were fitted and physical activity fluctuation scores were obtained by averaging the absolute values of regression residuals. The association between body fat after 5 years and the physical activity fluctuation score was assessed in linear regressions adjusting for baseline body fat, average number of physical activity sessions per week, diet and sociodemographic variables. Among boys, there were statistically significant positive associations between physical activity fluctuation and BMI (β, 95% confidence interval: 0.12, 0.02-0.21) and triceps skinfold (0.40, 0.17-0.63). The associations with waist circumference or subscapular skinfold were not statistically significant (0.22, -0.04-0.49; 0.13, -0.05-0.32, respectively). In girls, there were statistically significant negative associations between physical activity fluctuation and BMI (-0.12, -0.20 to -0.03), waist circumference (-0.54, -0.91 to -0.17), subscapular skinfold (-0.41, -0.56 to -0.26) and triceps skinfold (-0.22, -0.38 to -0.05). Physical activity fluctuations appear to affect body fat during adolescence. Sex-specific interventions may be needed given that greater physical activity fluctuations seem unfavourable for boys and beneficial for girls.