Women experience significant changes in endocrine function during aging. Decreasing levels of anabolic hormones may be associated with musculoskeletal atrophy and decrease in function that is observed in older women and, as a result, there has been an increase in the use of pharmacological hormone therapies. It is difficult to distinguish, however, between physiological changes that are truly age related and those that are associated with lifestyle factors such as physical activity participation. Some research has shown that circulating levels of anabolic hormones such as DHEA(S) and IGF-I in older women are related to physical activity, muscle function, and aerobic power. Exercise-intervention studies have generally shown that increasing age blunts the acute hormonal response to exercise, although this might be explained by a lower exercise intensity in older women. There have been relatively few studies that examine hormonal adaptations to exercise training. Physical activity might have an effect on hormone action as a result of changes in protein carriers and receptors, and future research needs to clarify the effect of age and exercise on these other components of the endocrine system. The value and safety of hormone supplements must be examined, especially when used in combination with an exercise program.
Jennifer L. Copeland, Samuel Y. Chu, and Mark S. Tremblay
John J. Reilly, Smita Dick, Geraldine McNeill, and Mark S. Tremblay
The Active Healthy Kids Scotland Report Card aims to consolidate existing evidence, facilitate international comparisons, encourage more evidence-informed physical activity and health policy, and improve surveillance of physical activity.
Application of the Active Healthy Kids Canada Report Card process and methodology to Scotland, adapted to Scottish circumstances and availability of data.
The Active Healthy Kids Scotland Report Card 2013 consists of indicators of 7 Health Behaviors and Outcomes and 3 Influences on Health Behaviors and Outcomes. Grades of F were assigned to Overall Physical Activity, Sedentary Behavior (recreational screen time), and Obesity Prevalence. A C was assigned to Active Transportation and a D- was assigned to Diet. Two indicators, Active and Outdoor Play and Organized Sport Participation, could not be graded. Among the Influences, Family Influence received a D, while Perceived Safety, Access, and Availability of Spaces for Physical Activity and the National Policy Environment graded more favorably with a B.
The Active Healthy Kids Canada process and methodology was readily generalizable to Scotland. The report card illustrated low habitual physical activity and extremely high levels of screen-based sedentary behavior, and highlighted several opportunities for improved physical activity surveillance and promotion strategies.
Mark S. Tremblay, Joel D. Barnes, and Jennifer Cowie Bonne
For 20 years Active Healthy Kids Canada (AHKC) has worked to inspire the country to engage all children and youth in physical activity (PA). The primary vehicle to achieve this is the AHKC Report Card on Physical Activity for Children and Youth, which has been released annually since 2005. Using 10 years of experience with this knowledge translation and synthesis mechanism, this paper aggregates and consolidates diverse evidence demonstrating the impact of the Report Card and related knowledge translation activities. Over the years many evaluations, consultations, assessments, and surveys have helped inform changes in the Report Card to improve its impact. Guided by a logic model, the various assessments have traversed areas related to distribution and reach, meeting stakeholder needs, use of the Report Card, its influence on policy, and advancing the mission of AHKC. In the past 10 years, the Report Card has achieved > 1 billion media impressions, distributed > 120,000 printed copies and > 200,000 electronic copies, and benefited from a collective ad value > $10 million. The Report Card has been replicated in 14 countries, 2 provinces, 1 state and 1 city. AHKC has received consistent positive feedback from stakeholders and endusers, who reported that the Report Card has been used for public awareness/education campaigns and advocacy strategies, to strengthen partnerships, to inform research and program design, and to advance and adjust policies and strategies. Collectively, the evidence suggests that the Report Card has been successful at powering the movement to get kids moving, and in achieving demonstrable success on immediate and intermediate outcomes, although the long-term goal of improving the PA of Canadian children and youth remains to be realized.
Jennifer L. Copeland, Kent C. Kowalski, Rachel M. Donen, and Mark S. Tremblay
To accommodate the need for longitudinal physical activity research, we developed the Physical Activity Questionnaire for Adults (PAQ-AD). The PAQ-AD is an adult version of the PAQ-C and PAQ-A questionnaires which were developed for older children and adolescents, respectively.
Two studies assessed the convergent validity of the PAQ-AD using a series of self-report tools and direct measurement of physical activity.
In the first sample (N = 247), the PAQ-AD was significantly related to a series of self-report tools (r = 0.53 to 0.64). In the second sample (N = 184), the PAQ-AD was significantly related to the self-report tools (r = 0.56 to 0.63), a physical activity recall interview (r = 0.24), and to direct measurements of physical activity (r = 0.26 to 0.43).
These results provide preliminary validity evidence for the PAQ-AD and suggest the PAQ “family” of questionnaires might be advantageous for longitudinal research assessing physical activity from childhood to adulthood.
Charles Boyer, Mark Tremblay, Travis Saunders, Allison McFarlane, Michael Borghese, Meghann Lloyd, and Pat Longmuir
This project examined the feasibility, validity, and reliability of the plank isometric hold for children 8–12 years of age. 1502 children (52.5% female) performed partial curl-up and/or plank protocols to assess plank feasibility (n = 823, 52.1% girls), validity (n = 641, 54.1% girls) and reliability (n = 111, 47.8% girls). 12% (n = 52/431) of children could not perform a partial curl-up, but virtually all children (n = 1066/1084) could attain a nonzero score for the plank. Plank performance without time limit was influenced by small effects with age (β = 6.86; p < .001, η2 = 0.03), flexibility (β = 0.79; p < .001, η2 = 0.03), and medium effects with cardiovascular endurance (β = 1.07; p < .001, η2 = 0.08), and waist circumference (β = −0.92; p < .001, η2 = 0.06). Interrater (ICC = 0.62; CI = 0.50, 0.75), intrarater (ICC = 0.83; CI = 0.73, 0.90) and test-retest (ICC = 0.63; CI = 0.46, 0.75) reliability were acceptable for the plank without time limit. These data suggest the plank without time limit is a feasible, valid and reliable assessment of torso muscular endurance for children 8–12 years of age.
Stella K. Muthuri, Lucy-Joy M. Wachira, Vincent O. Onywera, and Mark S. Tremblay
A physical activity transition to declining activity levels, even among children, now poses a serious public health concern because of its contribution to a rising prevalence of noncommunicable diseases. Childhood physical activity levels are associated with parental perceptions of the neighborhood; however, these relationships have not been explored in sub-Saharan Africa (SSA). The objective was to investigate relationships between parental perceptions of the neighborhood and physical activity indicators among Kenyan children.
Data were collected from children 9 to 11 years old in Nairobi as part of the International Study of Childhood Obesity, Lifestyle and Environment. Child physical activity was assessed by accelerometry, and information on obtaining sufficient physical activity, active transport, and parental perceptions of the neighborhood collected using questionnaires.
Of 563 participating children, 45.7%, 12.6%, and 11.4% used active school transportation, met physical activity guidelines, and were sufficiently active, respectively. Parental perception of positive neighborhood social cohesion, positive environs and connectivity, and negative child safety concerns, were associated with child physical activity outcomes.
Aspects of parental perceptions of the neighborhood were associated with child physical activity outcomes and should be further explored to appropriately inform policy and practice in curbing declining physical activity levels among children in SSA.
Lucy Kate Lewis, Carol Maher, Kevin Belanger, Mark Tremblay, Jean-Philippe Chaput, and Tim Olds
This study investigated associations between weather conditions, physical activity, and sedentary time in primary school-aged children in Australia and Canada.
Cross-sectional data on 9–11-year-old children from the Australian (n = 491) and Canadian (n = 524) sites of the International Study of Childhood Obesity, Lifestyle and the Environment were used. Minutes of daily moderate-to-vigorous-physical-activity (MVPA) and sedentary time were determined from 7-day, 24-h accelerometry (Actigraph GT3X+ triaxial accelerometer). Day-matched weather data (temperature, rainfall, snowfall, relative humidity, wind speed) were obtained from the closest weather station to participants’ schools. Covariates included parental highest education level, day type, sex, and BMI z-scores. Generalized mixed model analyses allowing for clustering of participants within schools were completed. Scatterplots with Loess curves were created for maximum temperature, MVPA, and sedentary time.
Daily maximum temperature was significantly associated with MVPA and sedentary time in Australia (MVPA p = .05, sedentary p = .01) and Canada (p < .001, p = .001). Rainfall was negatively associated with MVPA in Australia (p < .001) and positively associated with sedentary time in Canada (p = .02).
MVPA and sedentary time appear to be optimal when the maximum temperature ranges between 20°C and 25°C in both countries. The findings have implications for study design and interpretation for surveillance and intervention studies.
Richard Larouche, Travis John Saunders, Guy Edward John Faulkner, Rachel Colley, and Mark Tremblay
The impact of active school transport (AST) on daily physical activity (PA) levels, body composition and cardiovascular fitness remains unclear.
A systematic review was conducted to examine differences in PA, body composition and cardiovascular fitness between active and passive travelers. The Medline, PubMed, Embase, PsycInfo, and ProQuest databases were searched and 10 key informants were consulted. Quality of evidence was assessed with GRADE and with the Effective Public Health Practice Project tool for quantitative studies.
Sixty-eight different studies met the inclusion criteria. The majority of studies found that active school travelers were more active or that AST interventions lead to increases in PA, and the quality of evidence is moderate. There is conflicting, and therefore very low quality evidence, regarding the associations between AST and body composition indicators, and between walking to/from school and cardiovascular fitness; however, all studies with relevant measures found a positive association between cycling to/from school and cardiovascular fitness; this evidence is of moderate quality.
These findings suggest that AST should be promoted to increase PA levels in children and adolescents and that cycling to/from school is associated with increased cardiovascular fitness. Intervention studies are needed to increase the quality of evidence.
Mark S. Tremblay, Silvia A. Gonzalez, Peter T. Katzmarzyk, Vincent O. Onywera, and John. J. Reilly
Dale W. Esliger, Jennifer L. Copeland, Joel D. Barnes, and Mark S. Tremblay
The unequivocal link between physical activity and health has prompted researchers and public health officials to search for valid, reliable, and logistically feasible tools to measure and quantify free-living physical activity. Accelerometers hold promise in this regard. Recent technological advances have led to decreases in both the size and cost of accelerometers while increasing functionality (e.g., greater memory, waterproofing). A lack of common data reduction and standardized reporting procedures dramatically limit their potential, however. The purpose of this article is to expand on the utility of accelerometers for measuring free-living physical activity. A detailed example profile of physical activity is presented to highlight the potential richness of accelerometer data. Specific recommendations for optimizing and standardizing the use of accelerometer data are provided with support from specific examples. This descriptive article is intended to advance and ignite scholarly dialogue and debate regarding accelerometer data capture, reduction, analysis, and reporting.