Developmental Physical Activity Restriction and Enhancement Program Long-Term Metabolic and Locomotor Phenotypes in Mus musculus

BACKGROUND: Physical activity and inactivity are known to have opposing impacts on an individual’s health throughout their lifespan. Less is known about how different levels of physical activity during early life stages can impact physical function later in life. 

PURPOSE: This study investigates the impact of varying levels of physical activity in early life on physical function in early adulthood, and identifies indices of premature aging.

86 mice were separated into 2 cohorts: all completed 14 days of treatment from 3 to 5 weeks postnatal, involving voluntary wheel-running (VWR), early-life activity (ELA), standard cage sedentary (SED), small mouse cage (SMC), or hindlimb unloading (HU). The level of activity was as follows (VWR>ELA>SED>SMC>HU). After this 14-day period, ELA, SED, SMC and HU mice were placed in standard-size cages and allowed to ambulate freely while VWR maintained access to running wheels. Beginning at 6 months of age, mice underwent longitudinal metabolic and locomotor assessment using the AccuScan system, with testing repeated every 6 months. This poster compares outcomes at 6 and 12 months, with the study ongoing. Continuous 24-hour monitoring captured light and dark cycles. Locomotor activity (distance, activity count, rest time) was measured via infrared beam breaks across a 3D grid, while metabolic measures were assessed using indirect calorimetry. VO₂ and VCO₂ were used to calculate RER (VCO₂/VO₂), reflecting substrate utilization. The system was calibrated prior to testing, with experiments run continuously (≤8 mice/batch). Chambers were prepared with bedding, food, and water, and body weights were recorded prior to testing. Approved Under IACUC Protocol #1103_27