Failure to generalize determinants of self-reported physical activity to a motion sensor.

We hypothesized that the prediction of physical activity from psychological determinants would differ when free-living physical activity was assessed by electromechanical or self-report methods. We assessed outcome-expectancy values and perceived barriers for physical activity (OE Values/P Barriers) and physical self-efficacy in 44 young (24 yr +/- 4.8) Caucasian men (N = 13) and women (N = 31). Two weeks later, subjects kept a daily diary and wore a Caltrac motion sensor during all ambulation for seven consecutive days. Reliability (PI) across days was high for MET.h of activity estimated by the diary (0.82) and for Caltrac counts (0.87). Canonical correlation analysis yielded one significant linear combination (Rc = 0.55, P less than 0.01; redundancy = 0.19 to 0.24) of the set of psychological variables [OE Values/P Barriers (beta = 0.76) and physical self-efficacy (B = 0.33)] and the set of physical activity estimates [7-d diary (B = 0.89) and Caltrac (beta = 0.24)]. Multiple correlations indicated that the linear combination of OE Values/P Barriers and physical self-efficacy explained 26% of the variation in MET.h reported in the 7-d diary (P less than 0.01) but was unrelated to Caltrac counts (P greater than 0.05). The strongest bivariate model included the 7-d diary and OE Values/P Barriers (r = 0.51, P less than 0.01). Caltrac counts were weakly related to OE Values/P Barriers (r = 0.34, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement properties of the CHAMPS physical activity questionnaire in a sample of older Australians.

BACKGROUND: The effective evaluation of physical activity interventions for older adults requires measurement instruments with acceptable psychometric properties that are sufficiently sensitive to detect changes in this population. AIM: To assess the measurement properties (reliability and validity) of the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in a sample of older Australians. METHODS: CHAMPS data were collected from 167 older adults (mean age 79.1 S.D. 6.3 years) and validated with tests of physical ability and the SF-12 measures of physical and mental health. Responses from a sub-sample of 43 older adults were used to assess 1-week test-retest reliability. RESULTS: Approximately 25% of participants needed assistance to complete the CHAMPS questionnaire. There were low but significant correlations between the CHAMPS scores and the physical performance measures (rho=0.14-0.32) and the physical health scale of the SF-12 (rho=0.12-0.24). Reliability coefficients were highest for moderate-intensity (ICC=0.81-0.88) and lowest for vigorous-intensity physical activity (ICC=0.34-0.45). Agreement between test-retest estimates of sufficient physical activity for health benefits (> or =150min and > or =5 sessions per week) was high (percent agreement=88% and Cohen's kappa=0.68). CONCLUSION: These findings suggest that the CHAMPS questionnaire has acceptable measurement properties, and is therefore suitable for use among older Australian adults, as long as adequate assistance is provided during administration.     

Correlates of pedometer-measured and self-reported physical activity among young Australian adults

Accurately quantifying physical activity is important for investigating relations with potential correlates, but past studies have mostly relied on self-report measures, which may be susceptible to error and biases, limiting interpretability. This study aimed to examine correlates of pedometer-determined physical activity and compare them with correlates of self-reported physical activity. Cross-sectional data were taken from 2017 Australian adults (aged 26–36 years) who were involved in the Childhood Determinants of Adult Health follow-up study during 2004–2006. Daily steps were recorded for seven days using Yamax pedometers and physical activity (total min/week) was reported via the long International Physical Activity Questionnaire. Demographic, biological, behavioral, psychological, social and environmental factors were assessed. Lower education, blue collar occupation and higher mental health score (men) and low-moderate alcohol intake (women) were positively associated with self-report and pedometer-measured activity. Among men, body mass index (BMI) was inversely and physical health score was positively associated with pedometer-measured activity while smoking, low to moderate alcohol intake, higher general health and urban area of residence were positively associated with self-reported activity. Among women, age and general health status were positively associated and number of live births inversely associated with pedometer-measured activity, while lower education, blue collar occupation, part time employment, smoking, diet, higher physical health score and higher mental health score were positively associated and white collar occupation inversely associated with self-reported activity. Many physical activity correlates differed depending on the measure employed; researchers should be mindful of these differences when selecting measures of physical activity.     

Comparing self-reported physical activity and sedentary time to objective fitness measures in a military cohort

Objectives

Regular vigorous physical activity (PA) and high levels of physical fitness (PF) confer health benefits. Conversely, sedentary time is a risk factor for chronic illness, independent of PA. We evaluated associations between self-reported PA, sedentary time, and objective PF measures in military Service members.

Cross-sectional and longitudinal comparisons of self-reported and device-assessed physical activity and sedentary behaviour

ObjectivesTo examine the longitudinal associations and differences between self-reported and device-assessed physical activity (PA) and sedentary behaviour (SB), using a multifaceted statistical approach.DesignLongitudinal measurement burst.MethodsIn total, 52 university students (78% female) aged 18–38 years (mean = 21.94 ± 4.57 years) participated. The study consisted of three blocks of six days of measurement, during which participants wore an accelerometer on their wrist for the entire block, and self-reported their PA over the 6 days at the end of each block.ResultsMeaningful latent differences between methods were observed for moderate PA and SB across all three assessment periods, such that participants underreported the time spent in each activity. Bland–Altman plots revealed a positive mean difference for vigorous PA, with over-reporting increasing as mean levels increased. Negative mean differences were observed for all other intensities. Underreporting of moderate PA increased as the mean level increased, whereas for light PA and SB, underreporting decreased at high levels. Repeated measures correlations revealed a meaningful association for vigorous PA only, suggesting that as self-reported minutes increase so too do device-measured minutes.ConclusionsWe found evidence of cross-sectional and longitudinal differences and weak associations between self-reported and device-assessed PA and SB. Future work is needed to enhance the quality of self-reported methods to assess PA and SB (e.g., face and content validity), and consider improvements to the processing of device-based data.     

Physical activity, physical fitness and mortality in a sample of middle aged men followed-up 25 years.

One-thousand-seven-hundred-twelve men aged 40-59, representing two demographic samples of rural areas in Northern and Central Italy, were examined in 1960 and then followed-up for 25 years. Total mortality and coronary mortality were related to the entry measurements of physical activity at work, estimated in three levels by a simple questionnaire and to four possible indicators of physical fitness, ie resting heart rate, the circumference of the right arm cleaned from the contribution of skin and subcutaneous fat, vital capacity and forced expiratory volume in 3/4 sec, the latter two adjusted by height. The four indicators of fitness and the score of physical activity were somewhat related each other in the expected direction. Both all causes and coronary mortality were indirectly related to the score of physical activity. The relative risk for age adjusted rates of sedentary vs heavy workers was 1.23 for all causes of death, and 1.72 for coronary deaths. Direct univariate relationships were found between resting heart rate and mortality (for both all causes and coronary deaths) whereas indirect relationships were found for arm circumference and the two indicators of respiratory function. The age adjusted relative risks between the upper and the bottom quartile of the distribution were, for all causes of death, 0.75 for vital capacity, 0.68 for forced expiratory volume 1.32 for heart rate, and 0.84 for arm circumference. The correspondent relative risks for coronary deaths were 0.71, 0.65, 1.23 and 1.02 respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

A source of systematic bias in self-reported physical activity: The cutpoint bias hypothesis

ObjectivesEstimates of adults’ moderate-to-vigorous physical activity (MVPA) based on self-report are generally higher than estimates derived from criterion measures. This study examines a possible explanation for part of this discrepancy: the cutpoint bias hypothesis. This hypothesis proposes that inter- and intra-individual variability in energy expenditure, combined with the fact that adults perform a high proportion of daily activities at or just above the traditional 3 MET cutpoint, result in systematic over-estimates of MVPA.DesignCross-sectional.MethodsTime-use recalls (n = 6862) were collected using the Multimedia Activity Recall for Children and Adults from 2210 adults (1215 female, age 16–93 years) from 16 studies conducted in Australia and New Zealand between 2008-2017. Minutes spent in MVPA were estimated using models with varying levels of intra- and inter-individual (total variability) Unadjusted (0% total variability), Low (11.9%), Best Guess (20.7%), and High (30.0%).ResultsIn the Unadjusted model, participants accumulated an average of 129 (standard deviation 127) min/day of MVPA. Estimated MVPA was 98 (110), 99 (107) and 108 (107) min/day in the Low, Best Guess and High variability models, respectively, with intra-class correlation coefficients with the Unadjusted model ranging from 0.78 to 0.83.ConclusionsThese findings support the hypothesis of a cutpoint bias, which probably contributes to the large disparities seen between self-reported and criterion measures of MVPA. Future studies are needed to confirm these findings using other self-report instruments and in other populations.     

Effect of resistance training on self-reported physical functioning in HIV infection.

PURPOSE: To assess whether progressive resistance training (PRT) improves functional status, measured using a validated Physical Function Scale, in both wasted and nonwasted patients with HIV infection, and to compare the relative contributions of increased lean body mass (LBM) and increased strength with the change in physical function. METHODS: Six patients with AIDS wasting and 19 patients with HIV but without wasting trained three times per week for 8 wk, followed by 8 wk of usual activity. Physical function, strength, and LBM were measured at 0, 8, and 16 wk. Self-reported physical functioning was measured using the physical functioning subscale of the Medical Outcomes Study (MOS) Short Form-36 (SF-36) questionnaire. RESULTS: Significant improvements occurred in strength (1-RM averaged for four machines increased 44% in the nonwasted and 60% in the wasted patients, each P < 0.0001) and LBM (2.3% increase in the nonwasted and 5.3% in the wasted patients, each P < 0.05) with resistance training. Physical function increased significantly in the wasted subjects (6 points, P < 0.02) but not in the nonwasted subjects, so that at 16 wk the wasted subjects functioned at a higher level than the nonwasted patients (P < 0.05). Both increase in LBM (P < 0.001) and increase in strength (P < 0.001) were significantly and independently associated with increase in physical function. CONCLUSION: PRT increases functional status in patients with HIV wasting, both by increasing strength and by increasing LBM.     

Correlates of physical fitness improvement among a Navy remedial exercise sample.

This study investigated influences on physical fitness improvement among Navy remedial exercise program participants. Subjects were 27 Navy personnel who had failed to pass the body composition, aerobic fitness, or curl-up portion of the semiannual physical readiness test. The remedial exercise program consisted of three 1-hour exercise sessions per week for 16 weeks, with primary emphasis on running and walking. To determine influences on physical fitness improvement, physical readiness test and self-report survey data were collected and analyzed through bivariate Pearson correlation. No correlations were found between any of the study variables and weight change. Initial body fat was positively correlated (r = 0.470, p < 0.05), whereas initial body weight (r = -0.490, p < 0.05) and perceptions of exercise leadership (r = -0.690, p < 0.05) were negatively correlated with reductions in body fat. Positive correlates of improvements in 1.5-mile run time were initial run failure (r = 0.637, p < 0.01), perceived exercise benefits (r = 0.574, p < 0.01), and perceptions of social support (r = 0.543, p < 0.05). Exercise mode (walking group) was negatively correlated (r = -0.445, p < 0.05) with improvements in run time. In conclusion, this study demonstrated that various personal, program, and environmental factors influence improvements in physical fitness status.     

Aerobic physical activity assessed with accelerometer,diary, questionnaire,and interview in a Finnish population sample

This study evaluates the agreement between different methods to assess moderate to vigorous physical activity (MVPA) in a large sample of Finnish adults. Methods were classified and examined pairwise (accelerometer vs diary; questionnaire vs interview). Proportion of participants meeting the aerobic health‐enhancing physical activity (HEPA) recommendation was compared pairwise between all four methods. The present study of 1916 adults aged 18‐75 years (mean age 50 years, 57% women) is a sub‐sample of population‐based Health 2011 Study conducted by the National Institute of Health and Welfare in Finland. Participants used accelerometer for 7 days and completed physical activity (PA) diary during the same period. PA questionnaire and interview were completed retrospectively to assess typical weekly PA over the past year. Agreement between the methods was analyzed with paired samples t ‐test and Bland‐Altman plot. Kappa‐test was used to compare the prevalence of meeting the HEPA recommendation. The accelerometer resulted in 13 minutes (P  <  0.001) higher weekly total amount of MVPA compared to diary. According to Bland‐Altman plot, the 95% limit of agreement was from +273 to −247 in weekly minutes. The comparison between questionnaire and interview showed non‐significant mean difference of 3 minutes (P  =  0.60) in weekly MVPA, but the Bland‐Altman plot showing the 95% limit of agreement from +432 to −427 in weekly minutes. Agreement of meeting HEPA recommendation was moderate between questionnaire and interview (κ  = 0.43) but poor (κ  = 0.20‐0.38) between other comparisons. The inter‐method differences were large especially at the individual level. Thus the assessment of PA is strongly method‐dependent and not interchangeable.     

Daily physical activity related to aerobic fitness and body fat in an urban sample of children

This study evaluates associations between objectively measured daily physical activity vs aerobic fitness and body fat in children aged 8-11 years. A cross-sectional study of 225 children aged 7.9-11.1 years was performed. Abdominal fat mass (AFM) and total body fat (TBF) were quantified by dual-energy x-ray absorptiometry. TBF was calculated as percentage of total body mass (BF%). Body fat distribution was calculated as AFM/TBF. Aerobic fitness was measured by indirect calorimetry during a maximal cycle ergometer exercise test. Daily physical activity was assessed by accelerometers for 4 days and daily accumulation of moderate-to-vigorous and vigorous activity was calculated. Significant relationships (P<0.05) existed for vigorous activity vs ln BF% (r=-0.40), ln AFM (r=-0.35), TBF/AFM (r=-0.22) and aerobic fitness (r=0.38), whereas moderate-to-vigorous activity displayed weaker relationships (-0.22, -0.18, -0.12 NS, and 0.25). Multiple regression analyses with inclusion of possible confounders concluded that vigorous activity was independently related to aerobic fitness and ln BF% or ln AFM. Moderate-to-vigorous activity was only independently related to aerobic fitness. In this population, low daily accumulation of vigorous activity was, already in children aged 8-11 years, associated with more body fat and lower aerobic fitness. A similar relation was not found for daily accumulation of moderate-to-vigorous activity.     

An ecological model of predictors of stages of change for physical activity in Greek older adults

This study examined the usefulness of an ecological model in predicting stages of change for physical activity in Greek older adults. Three hundred and eighteen Greek older adults ( n =168 males; n =150 females) completed questionnaires measuring a range of personal, psycho-social and environmental characteristics. The ecological model consisted of personal (gender, age, body mass index and perceived health), psycho-social (barrier self-efficacy and number of friends exercising) and environmental (the presence of sidewalks, heavy traffic, hills, unattended dogs and frequently observing others' exercising) predictors. The model explained 51.10% of the variance; more than that explained by any of the individual classes of predictors in isolation. Number of friends exercising was a particularly salient predictor. The findings may enhance understanding of some of the reasons for the high prevalence of pre-contemplation in this population. The information may have implications for the design of effective exercise interventions.     

Development of a Scottish physical activity questionnaire: a tool for use in physical activity interventions

OBJECTIVES: Three studies were undertaken to establish the reliability and validity of the Scottish physical activity questionnaire (SPAQ), developed to aid seven day recall of leisure and occupational physical activity. METHODS: To establish reliability, SPAQs (n = 34) were completed on a Monday and the following Wednesday. Thus each questionnaire measured four identical days. To establish concurrent validity, 94 participants completed a SPAQ and an adapted stage of exercise behaviour change questionnaire. Responses to SPAQ were then analysed by stage of exercise behaviour change. In a further study of criterion validity, 30 volunteers wore a Caltrac motion sensor for four consecutive days, after which they completed a SPAQ. RESULTS: In the first study, total physical activity had a coefficient of repeatability (R) of 53 minutes. Occupational physical activity showed a similar variance (R = 54.6 minutes) but leisure physical activity was more reliable (R = 29.3 minutes). The main variation in occupational physical activity was found to be walking (R = 39.8 minutes). In study 2, a one way analysis of variance showed the expected relation between physical activity and stage of exercise behaviour change, confirming the concurrent validity of SPAQ with the stage of exercise behaviour change model. In study 3, several erroneous recordings affected both SPAQ and the Caltrac results (kcal). After relevant corrections had been made, the correlation between the two measurement devices was 0.52 (p < 0.05). CONCLUSIONS: SPAQ has been shown to be reliable and to hold strong concurrent validity and limited criterion validity. The main limitation in SPAQ appears to be the measurement of occupational walking. It is therefore recommended that further work be conducted to refine the measurement of this physical activity component. It is evident nonetheless that SPAQ can be used with confidence to measure outcomes in physical activity interventions when account is taken of its limitations.     

Long-term vigorous training in young adulthood and later physical activity as predictors of hypertension in middle-aged and older men

500 and 69 male former elite athletes and 319 male controls completed a health questionnaire in 1985 and in 1995. Register data on the subjects were also collected. Subjects were aged 65 years or less and had no history of hypertension in 1985, and they had been healthy at the age of 20 years. The athletes were grouped into endurance and mixed sports (n = 386), and power sports (n = 183). The cumulative 10-year incidence of hypertension up to 1995 was significantly lower in the endurance and mixed sports group (23.6 %) compared to the power sports group (33.3 %) or the control group (32.0 %). The difference between the endurance and mixed sports group and the two other groups was still significant after adjustment for age, but not after further adjustment for body mass index, alcohol consumption, and later physical activity. However, the trend of reduced risk remained. In conclusion, a history of being an elite athlete in endurance or mixed sports predicts a lower risk of hypertension in working age men, while a history of being an elite athlete in power sports appears to confer no benefit. Later physical activity was also associated with lower risk.