Daniel Arvidsson

Physical activity questionnaire for adolescents validated against doubly labelled water

Objective:To validate a physical activity questionnaire for adolescents (PAQA) adapted from the International Physical Activity Questionnaire (IPAQ).Design:Energy expenditure was measured during a 14-day period with doubly labelled water (DLW). PAQA was administered as an interview at the end of the period, asking for physical activity in school, during transportation and leisure-time, during a habitual week. Energy expenditure (EEPAQA) was calculated as the product of total physical activity+sleep and predicted resting metabolic rate, and was compared to energy expenditure from DLW (EEDLW), thermic effect of feeding excluded.Setting:Participants were recruited from grade 9 in a compulsory school in Göteborg, Sweden. All data were collected at school, and distribution of DLW and measuring of resting metabolic rate were performed at Sahlgrenska University Hospital.Subjects:A total of 33 adolescents (16 girls, 17 boys) 15.7 (0.4) y performed all measurements.Results:For the whole group, PAQA underestimated energy expenditure by 3.8 (1.7) MJ (P<0.001). There was a strong correlation (r=0.62, P<0.001) between EEPAQA and EEDLW, but not for boys (r=0.42, P=0.090) and girls (r=0.33, P=0.22) separately.Conclusions:PAQA is not able to predict energy expenditure in Swedish adolescents, largely explained by the amount of unreported time. The ability to rank adolescents energy expenditure is questioned because of the gender effect, although we found a strong correlation for the whole group.Sponsorship:Ingabritt and Arne Lundberg Foundation.

Free-living energy expenditure in children using multi-sensor activity monitors

AIMS To improve the energy expenditure algorithm of the activity monitor ActiReg, and to validate ActiReg and the activity monitor SenseWear in free-living children. METHODS The development of the ActiReg algorithm was performed in 20 healthy 11-13 years old children on treadmill walking and running with indirect calorimetry as reference. The original and new ActiReg algorithms and SenseWear using software versions InnerView 5.1 and 6.1 were validated in 20 healthy 14-15 years old children against doubly labelled water. RESULTS The new ActiReg algorithm improved the assessment of energy expenditure during walking and running, but the response from the monitor levelled off after 7 km h(-1). The new algorithm and InnerView 6.1 decreased the mean (sd) difference to doubly labelled water from 11 (25) (P<0.05) to 0 (22) kJ kg(-1) d(-1) for ActiReg, and from 17 (20) (P<0.01) to -10 (21) (P<0.05) kJ kg(-1) d(-1) for SenseWear. However, the correlations between energy expenditure and the individual error for the new ActiReg algorithm and InnerView 6.1 were r= -0.50 (P<0.05) and r= -0.73 (P<0.01). CONCLUSIONS The new ActiReg algorithm and InnerView 6.1 improved the activity monitors at group level, but the error was dependent on physical activity level. Both activity monitors need further developments for use in children.

Energy intake in Swedish adolescents: validation of diet history with doubly labelled water

Objective: To compare habitual energy intake (EI) estimated from diet history (DH) with total energy expenditure (TEE) measured with doubly labelled water (DLW) in adolescents.Design: DH included a detailed questionnaire and an interview. TEE was measured during a 14-day period. Adequate (AR), under- (UR) and over-reporters (OR) were defined from the ratio EI/TEE: AR 0.84–1.16, UR <0.84 and OR >1.16.Setting: Participants were recruited from grade 9 in a compulsory school in Göteborg, Sweden. All data were collected at school and DLW dosages were distributed at Sahlgrenska University Hospital.Subjects: A total of 35 adolescents (18 boys, 17 girls), 15.7 (0.4) y.Results: EI was 11.0 (3.6) MJ and TEE was 11.4 (2.1) MJ (P=0.42). DH was able to rank EI compared to TEE (Spearmans r=0.59, P⩽0.001). For girls, EI was 18% lower (P=0.0067) and for boys, EI was 7% higher (P=0.26) compared to TEE. The 95% limits of agreement for difference between TEE and EI were −5.6 to 6.5 MJ. In total, 20 subjects were defined as AR (57%), nine as UR (26%) and six as OR (17%). Energy from in-between meals was 33% lower (P=0.0043) in UR girls and 57% higher (P=0.026) in OR boys, compared to adequate reporting girls and boys, respectively. In UR girls, energy-adjusted intake (10 MJ) of specific foods did not differ significantly, fat was lower and carbohydrate and vitamin C were higher compared to AR girls (all P<0.05). OR boys had no significant differences in food and nutrient intake in 10 MJ compared to AR boys.Conclusion: The diet history was able to capture EI for the group and to rank subjects. There was a wide individual range in reporting- accuracy related to gender.Sponsorship: The Ingabritt and Arne Lundberg Foundation, The Wilhelm and Martina Lundgren Foundation.

Energy Cost in Children Assessed by Multisensor Activity Monitors

PURPOSE The SenseWear Pro2 Armband (SWA; BodyMedia, Inc., Pittsburg, PA), the Intelligent Device for Energy Expenditure and Activity (IDEEA; Minisun LLC, Fresno, CA), and the ActiReg (AR; PreMed AS, Oslo, Norway) were compared with indirect calorimetry to determine the ability of these devices to assess energy cost in children during resting and different physical activities. METHODS Fourteen children, 11-13 yr old, wore the SWA, the IDEEA, and the AR during resting, sitting, stationary bicycling, jumping on a trampoline, playing basketball, stair walking, and walking/running along a 50-m track. The Oxycon Mobile portable metabolic system (VIASYS Healthcare, Conshohocken, PA) was used as the criterion method for energy cost. RESULTS For resting and sitting, the three activity monitors showed comparable results, but none of them accurately assessed energy cost for stationary bicycling, jumping on a trampoline, or playing basketball. The IDEEA was the only activity monitor that accurately assessed energy cost for stair walking. Also, the IDEEA showed a close estimate of energy cost across the walking and the running intensities, whereas the SWA accurately assessed energy cost for slow to normal walking but showed increased underestimation of energy cost with increasing speed. The AR overestimated energy cost during walking and during slow running but did not respond to increasing running speed. CONCLUSIONS To be able to capture childrens physical activity, all three activity monitors need to be further developed. Overall, the IDEEA showed the highest ability to assess energy cost in this study, but SWA may be more feasible for use in children under free-living conditions.

Minnesota Leisure Time Activity Questionnaire and Doubly Labeled Water in Adolescents

PURPOSES To validate the energy expenditure estimated from The Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) with total energy expenditure (TEE) measured by doubly labeled water (DLW), and to present and examine the validity of an extended version of the MLTPAQ with additional questions about inactivity during leisure time (eMLTPAQ), in a sample of Swedish 15-yr-old adolescents. METHODS Thirty-five 15-yr-old adolescents were interviewed using the eMLTPAQ. In addition to anthropometry, indirect calorimetry was measured to assess basal metabolic rate, and TEE was assessed by the DLW method over a 14-d period. RESULTS Energy expenditure calculated from MLTPAQ correlated well with TEEDLW (r=0.49, P<0.01), and the correlation increased when including questions about inactivity (r=0.73, P<0.01). However, eMLTPAQ underestimated TEE in 34 of the 35 students, with a mean difference between the methods of 2.8 MJ.d(-1) (95% limits of agreement: -0.1 to 5.6 MJ.d(-1)), which mainly was explained by a relative high intensity in the time which remained unreported. CONCLUSION eMLTPAQ is valid in ranking adolescents energy expenditure and in describing patterns of leisure time physical activities.

Physical Activity and Concordance between Objective and Perceived Walkability.

PURPOSE The studys purpose was to investigate concordance between objective and perceived neighborhood walkability, their associations with self-reported walking and objective physical activity, and sociodemographic characteristics of individuals in neighborhoods with objectively assessed high walkability who misperceive it as low. METHODS In 1925 individuals age 20-66 yr of both high and low neighborhood walkability recruited from administrative areas in the city of Stockholm, Sweden, objective neighborhood walkability was assessed within a 1000-m radius of each individuals residential address using geographic information systems. Perceived walkability was based on the Neighborhood Environment Walkability Scale. Walking was assessed using the International Physical Activity Questionnaire, and total physical activity and moderate-to-vigorous physical activity (MVPA) were assessed by an accelerometer (ActiGraph). Sociodemographic characteristics were self-reported. RESULTS Objective and perceived neighborhood walkability agreed in 67.0% of the individuals, with κ = 0.34 (95% confidence interval (CI) = 0.30-0.38). One-third of the individuals in neighborhoods with objectively assessed high walkability misperceived it as low. This nonconcordance was more common among older and married/cohabiting individuals. After adjustment for sociodemographic characteristics, high objective neighborhood walkability was associated with 35.0 (95% CI = 14.6-64.6) and 10.5 (95% CI = -5.2 to 28.5) more minutes per week of walking for transportation and leisure, respectively, and 2.8 (95% CI = 0.9-5.0) more minutes per day of MVPA. High perceived neighborhood walkability was associated with 41.5 (95% CI = 15.8-62.9) and 21.8 (95% CI = 2.8-40.0) more minutes per week of walking for transportation and leisure, respectively, and 1.7 (95% CI = -0.3 to 3.7) more minutes per day of MVPA. CONCLUSIONS Objective and perceived neighborhood walkability both contribute to the amount of walking and objective physical activity. Both measures of neighborhood walkability may be important factors to target in interventions aiming at increasing physical activity.

Walkability parameters, active transportation and objective physical activity: moderating and mediating effects of motor vehicle ownership in a cross-sectional study

BackgroundNeighborhood walkability has been associated with physical activity in several studies. However, as environmental correlates of physical activity may be context specific, walkability parameters need to be investigated separately in various countries and contexts. Furthermore, the mechanisms by which walkability affects physical activity have been less investigated. Based on previous research, we hypothesized that vehicle ownership is a potential mediator. We investigated the associations between walkability parameters and physical activity, and the mediating and moderating effects of vehicle ownership on these associations in a large sample of Swedish adults.MethodsResidential density, street connectivity and land use mix were assessed within polygon-based network buffers (using Geographic Information Systems) for 2,178 men and women. Time spent in moderate to vigorous physical activity was assessed by accelerometers, and walking and cycling for transportation were assessed by the International Physical Activity Questionnaire. Associations were examined by linear regression and adjusted for socio-demographic characteristics. The product of coefficients approach was used to investigate the mediating effect of vehicle ownership.ResultsResidential density and land use mix, but not street connectivity, were significantly associated with time spent in moderate to vigorous physical activity and walking for transportation. Cycling for transportation was not associated with any of the walkability parameters. Vehicle ownership mediated a significant proportion of the association between the walkability parameters and physical activity outcomes. For residential density, vehicle ownership mediated 25% of the association with moderate to vigorous physical activity and 20% of the association with the amount of walking for transportation. For land use mix, the corresponding proportions were 34% and 14%. Vehicle ownership did not moderate any of the associations between the walkability parameters and physical activity outcomes.ConclusionsResidential density and land use mix were associated with time spent in moderate to vigorous physical activity and walking for transportation. Vehicle ownership was a mediator but not a moderator of these associations. The present findings may be useful for policy makers and city planners when designing neighborhoods that promote physical activity.

Availability of exercise facilities and physical activity in 2,037 adults: cross-sectional results from the Swedish neighborhood and physical activity (SNAP) study

BackgroundExercise facilities may have the potential to promote physical activity among residents, and to support an active lifestyle throughout the year. We investigated the association between objectively assessed availability of exercise facilities and objectively assessed physical activity outcomes, and whether time of year had a modifying effect on these associations.MethodsA total of 2,037 adults (55% females) wore an accelerometer for seven days. Time spent in moderate to vigorous physical activity (minutes per day) and meeting the physical activity recommendations (yes/no) were used as outcome variables. Availability of exercise facilities was measured within 1,000-meter line-based road network buffers around participants’ residential addresses using Geographic Information Systems. Socio-demographic variables and time of year were included as covariates in the analyses.ResultsParticipants with ≥4 exercise facilities within their buffer zones spent 5.4 (confidence interval (CI) = 2.3-8.5) more minutes in moderate to vigorous physical activity per day, and had 69% higher odds (OR = 1.69; CI = 1.39-2.05) of meeting the physical activity recommendations, compared to those with no exercise facilities within their buffer zones. Time of year had no modifying effect on these associations.ConclusionsOur results show that objective availability of exercise facilities was associated with accelerometer-assessed time spent in moderate to vigorous physical activity and the odds of meeting the recommended levels of physical activity. Neighborhoods may be a logical and potentially significant venue for policy interventions aimed at increasing physical activity in the overall population.

Physical activity, sports participation and aerobic fitness in children who have undergone surgery for congenital heart defects

Aim:  To investigate physical activity, sports participation and aerobic fitness in children who have undergone surgery for congenital heart defects.

Sampling frequency affects the processing of Actigraph raw acceleration data to activity counts

ActiGraph acceleration data are processed through several steps (including band-pass filtering to attenuate unwanted signal frequencies) to generate the activity counts commonly used in physical activity research. We performed three experiments to investigate the effect of sampling frequency on the generation of activity counts. Ideal acceleration signals were produced in the MATLAB software. Thereafter, ActiGraph GT3X+ monitors were spun in a mechanical setup. Finally, 20 subjects performed walking and running wearing GT3X+ monitors. Acceleration data from all experiments were collected with different sampling frequencies, and activity counts were generated with the ActiLife software. With the default 30-Hz (or 60-Hz, 90-Hz) sampling frequency, the generation of activity counts was performed as intended with 50% attenuation of acceleration signals with a frequency of 2.5 Hz by the signal frequency band-pass filter. Frequencies above 5 Hz were eliminated totally. However, with other sampling frequencies, acceleration signals above 5 Hz escaped the band-pass filter to a varied degree and contributed to additional activity counts. Similar results were found for the spinning of the GT3X+ monitors, although the amount of activity counts generated was less, indicating that raw data stored in the GT3X+ monitor is processed. Between 600 and 1,600 more counts per minute were generated with the sampling frequencies 40 and 100 Hz compared with 30 Hz during running. Sampling frequency affects the processing of ActiGraph acceleration data to activity counts. Researchers need to be aware of this error when selecting sampling frequencies other than the default 30 Hz.