Exploring the ActiLife(®) filtration algorithm: converting raw acceleration data to counts.

Though portable accelerometers are ubiquitous in physiology and public health studies, their accuracy as objective measures of physical activity is still being examined. This paper enumerates and analyzes the various biases of the widely used ActiLife(®) software in reporting activity counts from ActiGraph(®) accelerometers. In particular, we focus on the two-stage proprietary filtration algorithm used to convert raw acceleration data, for a sampling rate of 30 Hz, to compressed 1 Hz signals; we develop simple novel methods to analyze the action of the software filter on the raw data in the frequency domain.

Accelerometer-measured versus self-reported physical activity in college students: implications for research and practice.

Objective: To determine the level of moderate-vigorous-intensity physical activity (MVPA) assessed via self-report and accelerometer in the college population, and to examine intrapersonal and contextual variables associated with physical activity (PA).

Participants: Participants were 77 college students at a university in the northwest sampled between January 2011 and December 2011.

Methods: Participants completed a validated self-report measure of PA and measures of athletic identity and benefits and barriers to exercise.

Cognitive and locomotor/exploratory behavior after chronic exercise in the olfactory bulbectomy animal model of depression.

Despite the evidence that exercise improves cognitive behavior in animal models, little is known about these beneficial effects in animal models of pathology. We examined the effects of activity wheel (AW) running on contextual fear conditioning (CFC) and locomotor/exploratory behavior in the olfactory bulbectomy (OBX) model of depression, which is characterized by hyperactivity and changes in cognitive function. Twenty-four hours after the conditioning session of the CFC protocol, the animals were tested for the conditioned response in a conditioned and a novel context to test for the effects of both AW and OBX on CFC, but also the context specificity of the effect.

Neurobiology of exercise.

Voluntary physical activity and exercise training can favorably influence brain plasticity by facilitating neurogenerative, neuroadaptive, and neuroprotective processes. At least some of the processes are mediated by neurotrophic factors. Motor skill training and regular exercise enhance executive functions of cognition and some types of learning, including motor learning in the spinal cord.