Voluntary running time and distance, treadmill running performance, energy uptake during voluntary running period, body weight, and relative heart weight, as well as serum insulin and NEFA concentrations were significantly related to skeletal muscle gene expression patterns (Fig. 4 and Supplemental Fig. S1).
Beginning at 6 weeks of age, rats selectively bred for high (HVR) versus low voluntary running distance (LVR) behaviors were housed in a complex design with or without voluntary running wheels being fed either a standard or Western (WD, 42% kcal from fat and added sucrose) diet for 8 weeks.
Meanwhile, a third group of rats ran on little mechanized treadmills, at a steady, even pace, without fits and starts of voluntary running.
Voluntary running was performed using a wheel system for a period of 8 weeks.
Voluntary running, regardless of fat content, significantly decreased bone volume fraction, Tb.N, connectivity density, and BMD and increased Tb.Sp.
In these mice, voluntary running improved body weight, but exacerbated CV markers, including plasma glucose and triglyceride levels.
Analysis of voluntary running wheel activity in mice is a useful phenotypic measure of skeletal muscle function.
Repeated intermittent administration of amphetamines acutely increases appetitive and consummatory aspects of motivated behaviors as well as general activity and exploratory behavior, including voluntary running wheel activity.
Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines.
The deleterious effect of voluntary running on trabecular structural characteristics indicates that there may be a maximal threshold of running beyond which beneficial effects cease and detrimental effects occur.
