Selection for aerobic capacity affects corticosterone, monoamines and wheel-running activity

Area of Science:

• Exercise Physiology
• Behavioral Genetics
• Animal Behavior

Background:

• Previous studies suggest a genetic link between aerobic capacity and voluntary exercise in mice.
• Understanding this relationship is crucial for insights into exercise motivation and physiological adaptation.

Purpose of the Study:

• To investigate the relationship between intrinsic aerobic capacity and voluntary wheel-running behavior in female rats.
• To identify potential physiological differences underlying variations in exercise activity.

Main Methods:

• Bidirectional selection of female rats into high capacity runners (HCR) and low capacity runners (LCR) based on aerobic endurance.
• Measurement of voluntary wheel-running activity over an eight-week period.
• Analysis of plasma corticosterone and striatal dopaminergic activity post-exercise.

Main Results:

• HCR rats exhibited significantly greater total wheel-running distance per day (33% more) compared to LCR rats.
• HCR rats showed increased running speed, duration, and number of running bouts.
• Differences in corticosterone and dopaminergic activity suggest physiological divergences influencing behavior.

Conclusions:

• A strong positive genetic correlation exists between aerobic capacity and voluntary exercise behavior in rats.
• This conserved relationship highlights the interplay between physiological potential and behavioral drive for physical activity.
• Findings contribute to understanding the evolution of exercise behavior and its physiological underpinnings.