This study investigated children’s after-school activity and associations with body mass index (BMI) and family circumstance. One thousand two hundred thirty-four parents and 854 children (age 8–13 years) completed activity diaries for the 2 hours after school. Parents reported children as more active than children reported themselves. Boys were reported to be more active than girls. Activity levels were generally not associated with BMI or family circumstance with the exception of cultural background. Parent-reported mean child METs were higher for mothers born in Australia (3.3 vs. 3.0; p = .02). Child-reported mean METs were higher for fathers born in Australia (2.9 vs. 2.6; p = .04) and where English was their main language (2.9 vs. 2.3, p = .003).
Kylie Hesketh, Melissa Graham and Elizabeth Waters
Lauren Ashleigh Waters, Benedicte Galichet, Neville Owen and Elizabeth Eakin
Taking a representative snapshot of physical activity intervention trial findings published between 1996 and 2006, we empirically evaluated participant characteristics, response and retention rates, and their associations with intervention settings.
A structured database search identified 5 representative health behavior journals, from which 32 research reports of physical activity intervention trials were reviewed. Interventions settings were categorized as workplace, healthcare, home- or community-based. Information on participant and intervention characteristics was extracted and reviewed.
The majority of participants were Caucasian (86%), women (66%), healthy but sedentary (63%), and middle-aged (mean age = 51 years). Intervention response rates ranged from 20% to 89%, with the greatest response rate for healthcare and home-based interventions. Compared with nonparticipants, study participants tended to be women, Caucasian, tertiary-educated, and middle-class. Participants in workplace interventions were younger, more educated, and healthier; in community-based interventions, participants were older and more ethnically diverse. Reporting on education and income was inconsistent. The mean retention rate was 78%, with minimal differences between intervention settings.
These results emphasize the need for physical activity interventions to target men, socioeconomically disadvantaged, and ethnic minority populations. Consistent reporting of response rate and retention may enhance the understanding of which intervention settings best recruit and retain large, representative samples.
Lauren Waters, Marina Reeves, Brianna Fjeldsoe and Elizabeth Eakin
Several recent physical activity intervention trials have reported physical activity improvements in control group participants. Explanations have been proposed, but not systematically investigated.
A systematic review of physical activity intervention trials was conducted to investigate the frequency of meaningful improvements in physical activity among control group participants (increase of ≥ 60 minutes [4 MET·hours] of moderate-to-vigorous physical activity per week, or a 10% increase in the proportion of participants meeting physical activity recommendations), and possible explanatory factors. Explanatory factors include aspects of behavioral measurement, participant characteristics, and control group treatment.
Eight (28%) of 29 studies reviewed reported meaningful improvements in control group physical activity, most of which were of similar magnitude to improvements observed in the intervention group. A number of factors were related to meaningful control group improvements in physical activity, including the number of assessments, mode of measurement administration, screening to exclude active participants, and preexisting health status.
Control group improvement in physical activity intervention trials is not uncommon and may be associated with behavioral measurement and participant characteristics. Associations observed in this review should be evaluated empirically in future research. Such studies may inform minimal contact approaches to physical activity promotion.