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Background: Physical activity (PA) has acquired a significant relevance due to the health benefits associated with its practice. Accelerometers are an effective tool to assess PA; however, the diversity of cut-off points used to define different PA intensities through accelerometry could interfere in the interpretation of the findings among studies. Objectives: The present study aimed to examine the sedentary behavior (SB) and physical activity (PA) levels in children using six selected accelerometry protocols based on diverse cut-off points. Methods: Clinical examination, anthropometric measurements, and PA evaluation by accelerometry were assessed in 543 selected children (10 ± 2.4 years old) from the Spanish GENOBOX study. The ActiLife data scoring program was used to determine daily min spent in SB, and light, moderate, vigorous and moderate-vigorous PA using six validated accelerometry protocols differing in their cut-off points. Results: Very different estimations for SB and PA intensity levels were found in children, independently of the non-wear-time algorithm selected, and considering puberty stages, age and body mass index. The time spent in daily SB varied from 471 to 663.7 min, PA ranged from 141 to 301.6 min, and the moderate-vigorous PA was reported between 20.7 and 180.2 min. Conclusion: The choice of a particular accelerometry protocol considering these factors is important to evaluate SB or PA intensities to suit the characteristics of the sample researched. It seems necessary to establish future lines of research that include different analytical approaches to measure SB and PA by accelerometry based on standardized and validated methodology. [ABSTRACT FROM AUTHOR]

Objectives To quantify and compare the sedentary time estimated by the Sedentary Behavior Questionnaire (SBQ) and the sedentary time objectively measured by a multi-sensor monitor (SWA) in pregnant women. Methods One hundred eighty-six participants answered the SBQ and wore the SWA at least 7 valid days. The concordance, correlation, agreement and relative activity levels between both measures of sedentary time were examined. Differences of sedentary time between weekday and weekend and between groups stratified by sociodemographic and clinical characteristic were evaluated by one-way analysis of variance. Results Pregnant women were sedentary the 64% of their waking hours. Television viewing is the most prevalent sedentary behavior. The concordance, correlation, and agreement between SBQ and SWA were weak, yet a significant correlation in weekday and average day sedentary time (r = 0.23 and 0.20, P = 0.001 and 0.008, respectively) was observed. A significant linear trend was found for increasing sedentary time between both methods using a relative activity levels analysis. Conclusions for Practice Pregnant women experience high amount of sedentary time, for approximately half of the day. The SBQ shows a low validity and agreement, but strong ability to rank individuals compared with SWA in pregnant women. [ABSTRACT FROM AUTHOR]

Objective: Valid and simple instruments to assess physical activity (PA) in specific populations are required for health-related research. The aim of the present study was to assess the validity of the Bouchard activity diary (AD) in Spanish adolescents using an activity monitor to compare total PA and moderate-to-vigorous PA (MVPA) obtained by both instruments. Design: Sixty-one Spanish adolescents, aged 12-16 years, completed the Bouchard AD and wore the ActiGraph activity monitor for three consecutive days. Validity was assessed with the Spearman correlation coefficient (r), the Bland-Altman method and the k coefficient. Results: Thirty-seven adolescents were included in the final analysis. Correlations between the activity monitor and the AD administered over the three days (Thursday-Saturday) were moderate (r=0·33-0·35, P<0·05) or non-significant for total PA and moderate (r=0·36, P<0·05) for MVPA. Correlations between the two methods were progressively lower for each subsequent day of testing, for both total PA and MVPA. The Bland-Altman plot illustrated that the Bouchard AD overestimated MVPA (mean difference 232·05 (SD 74·56) min; 95% limits of agreement 109·61, 2173·31 min). Agreements for classification into MVPA tertiles and accordance with the international recommendations of MVPA were fair and moderate, respectively, for the 3 d means. Conclusions: The Bouchard AD has reasonable validity to assess total PA and MVPA in Spanish adolescents. The results show lower levels of agreement on the third day but it is not clear if this is due to design features (weekday v. weekend) or to participant compliance with the survey or the activity monitoring protocol. [ABSTRACT FROM AUTHOR]

Tools for measuring walking time make use of objective and subjective methods. One subjective approach is to administer physical activity questionnaires (PAQ), mainly because they are inexpensive and easy to give to large groups. The European Prospective Investigation into Cancer and Nutrition (EPIC) study has a brief PAQ (EPIC-PAQ) and includes one question referencing walking time. The objective of this study was to assess the validity of the question about time spent walking included in the EPIC-PAQ. The sample included 200 older adults (113 women). To assess daily walking time, participants responded to the EPIC-PAQ in an interview and wore a portable gait analysis system and physical activity monitor for 48 consecutive hours in free-living condition. Results indicated that the mean of bias between the EPIC-PAQ and objetive measurement was -64.6 min/day. Also, the correlation was low compared to an objective measurement (rho = 0.196) and was positively correlated with the time spent at speeds below 2.5 mph but the correlation was low (slow walking rho = 0.154 and pace walking rho = 0.163). The EPIC-PAQ shows low correlations with the objective measurement of walking time, that suggests it may be inaccurate and affecting the estimate of the EPIC-PAQ's PA energy expenditure in this age group.

The aim of this study was to assess the reliability and convergent validity of the 7-day Physical Activity Recall (7-day PAR) interview in a sample of the Spanish population. Valid 7-day PAR interviews were conducted and RT3 accelerometer measurements taken for 160 subjects from the primary care population aged 24–83, 75 men and 85 women. Two 7-day PAR interviews were conducted, with a one-week interval, with 147 of these participants. Test–retest reliability was assessed using intraclass correlation coefficients. Convergent validity between the 7-day PAR and the accelerometer data were examined using Spearman's correlation coefficients, and the kappa index of agreement was calculated. The 7-day PAR reliability coefficients were 0.68 (95%CI: 0.58–0.76) for total energy expenditure, 0.65 (95%CI: 0.54–0.73) for the activity dose, and 0.61 (95%CI: 0.50–0.70) and 0.75 (95%CI: 0.67–0.81) for time spent on moderate and vigorous-intensity activity, respectively. These coefficients ranged from 0.91 to 0.96 in participants who reported a typical week in both interviews. Convergent validity ranged from 0.25 for time spent on vigorous activity to 0.52 for the activity dose, and the kappa index was 0.43 (95%CI: 0.30–0.56). Reliability and convergent validity coefficients in the Spanish population were generally moderate and similar to those found in other studies. [ABSTRACT FROM AUTHOR]