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 cutpoint for a group of older adults and to then assess the group's physical activity for 7 days. Participants (N=38; 69.7 ± 3.5 years) completed a laboratory-based calibration with an Actigraph 7164 accelerometer. The cutpoint defining moderate to vigorous physical activity (MVPA) was 1041 counts per minute. On average, participants obtained 68 minutes of MVPA per day, although more than 65% occurred as sporadic activity. Longer bouts of activity occurred in the morning (06:00-12:00) more frequently than other portions of the day. Almost 14 hours per day were spent in light intensity activity. This study demonstrates the rich information accelerometers provide about older adult activity patterns-information that may further our understanding of the relationship between physical activity and healthy aging.

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.

Sedentary time (ST) is an important risk factor for a variety of health outcomes in older adults. Consensus is needed on future research directions so that collaborative and timely efforts can be made globally to address this modifiable risk factor. In this review, we examined current literature to identify gaps and inform future research priorities on ST and healthy ageing. We reviewed three primary topics:(1) the validity/reliability of self-report measurement tools, (2) the consequences of prolonged ST on geriatric-relevant health outcomes (physical function, cognitive function, mental health, incontinence and quality of life) and(3) the effectiveness of interventions to reduce ST in older adults. Methods A trained librarian created a search strategy that was peer reviewed for completeness.

The purpose of this study was to determine the acute anabolic and catabolic hormone response to endurance and resistance exercise bouts of equal volume in subjects with differing training status. Twenty-two healthy men were recruited who were either resistance trained (n = 7), endurance trained (n = 8), or sedentary (n = 7). Three sessions were completed: a resting session, a 40-min run at 50-55% maximal oxygen consumption, and a resistance exercise session. Expired gases were monitored continuously during exercise, and the endurance and resistance exercise sessions were individually matched for caloric expenditure. Blood samples were drawn before exercise and 1, 2, 3, and 4 h after the start of the exercise. Plasma was analyzed for luteinizing hormone, dehydroepiandrosterone sulfate, cortisol, and free and total testosterone. Androgens increased in response to exercise, particularly resistance exercise, whereas cortisol only increased after resistance exercise. Dehydroepiandrosterone sulfate levels increased during the resistance exercise session and remained elevated during recovery in the resistance-trained subjects. Endurance-trained subjects displayed less pronounced changes in hormone concentrations in response to exercise than resistance-trained subjects. After an initial postexercise increase, there was a significant decline in free and total testosterone during recovery from resistance exercise (P < 0.05), particularly in resistance-trained subjects. On the basis of the results of this study, it appears that the endogenous hormone profile of men is more dependent on exercise mode or intensity than exercise volume as measured by caloric expenditure. The relatively catabolic environment observed during the resistance session may indicate an intensity-rather than a mode-dependent response.

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