Despite widespread use of accelerometers to objectively monitor physical activity among adults and youth, little attention has been given to older populations. The purpose of this study was to define an accelerometer-count cut point for a group of older adults and to then assess the group’s physical activity for 7 days. Participants (N = 38, age 69.7 ± 3.5 yr) completed a laboratory-based calibration with an Actigraph 7164 accelerometer. The cut point defining moderate to vigorous physical activity (MVPA) was 1,041 counts/min. On average, participants obtained 68 min of MVPA per day, although more than 65% of this occurred as sporadic activity. Longer bouts of activity occurred in the morning (6 a.m. to 12 p.m.) more frequently than other times of the day. Almost 14 hr/day were spent in light-intensity activity. This study demonstrates the rich information that accelerometers provide about older adult activity patterns—information that might further our understanding of the relationship between physical activity and healthy aging.
Jennifer L. Copeland and Dale W. Esliger
Michelle R. Stone, Dale W. Esliger and Mark S. Tremblay
The purpose of this study was to determine the effects of age and leg length on the energy-expenditure predictions of five activity monitors. Participants (N = 86, ages 8–40 years) performed three progressive bouts of treadmill activity ranging from 4 to 12 km/hr. Differences between measured energy expenditure (VO2) and activity-monitor-predicted energy expenditure were assessed across five leg length categories to determine the influence of leg length. Accelerometer counts or pedometer steps along with age, weight, and leg length accounted for 85–94% of measured energy expenditure. The addition of age and leg length as predictor variables explained a larger amount of variance in energy expenditure across all speeds. Differences in leg length and age might affect activity-monitor validity and, therefore, should be controlled for when estimating physical activity energy expenditure.
Emily Knox, Stuart Biddle, Dale W. Esliger, Joe Piggin and Lauren Sherar
Mass media campaigns are an important tool for promoting health-related physical activity. The relevance of sedentary behavior to public health has propelled it to feature prominently in health campaigns across the world. This study explored the use of messages regarding sedentary behavior in health campaigns within the context of current debates surrounding the association between sedentary behavior and health, and messaging strategies to promote moderate-to-vigorous physical activity (MVPA).
A web-based search of major campaigns in the United Kingdom, United States, Canada, and Australia was performed to identify the main campaign from each country. A directed content analysis was then conducted to analyze the inclusion of messages regarding sedentary behavior in health campaigns and to elucidate key themes. Important areas for future research were illustrated.
Four key themes from the campaigns emerged: clinging to sedentary behavior guidelines, advocating reducing sedentary behavior as a first step on the activity continuum and the importance of light activity, confusing the promotion of MVPA, and the demonization of sedentary behavior.
Strategies for managing sedentary behavior as an additional complicating factor in health promotion are urgently required. Lessons learned from previous health communication campaigns should stimulate research to inform future messaging strategies.
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.
Samantha Stephens, Tim Takken, Dale W. Esliger, Eleanor Pullenayegum, Joseph Beyene, Mark Tremblay, Jane Schneiderman, Doug Biggar, Pat Longmuir, Brian McCrindle, Audrey Abad, Dan Ignas, Janjaap Van Der Net and Brian Feldman
The purpose of this study was to assess the criterion validity of existing accelerometer-based energy expenditure (EE) prediction equations among children with chronic conditions, and to develop new prediction equations. Children with congenital heart disease (CHD), cystic fibrosis (CF), dermatomyositis (JDM), juvenile arthritis (JA), inherited muscle disease (IMD), and hemophilia (HE) completed 7 tasks while EE was measured using indirect calorimetry with counts determined by accelerometer. Agreement between predicted EE and measured EE was assessed. Disease-specific equations and cut points were developed and cross-validated. In total, 196 subjects participated. One participant dropped out before testing due to time constraints, while 15 CHD, 32 CF, 31 JDM, 31 JA, 30 IMD, 28 HE, and 29 healthy controls completed the study. Agreement between predicted and measured EE varied across disease group and ranged from (ICC) .13–.46. Disease-specific prediction equations exhibited a range of results (ICC .62–.88) (SE 0.45–0.78). In conclusion, poor agreement was demonstrated using current prediction equations in children with chronic conditions. Disease-specific equations and cut points were developed.