| Weigh mice before and after treatment
||Assess body composition before and after treatment
||Lean mass and fat mass
||Collect metabolic measurements and measure food and water intake before and after treatment
- Treadmill (Exer 3/6, Columbus Instruments, Columbus OH)
- Whole body MRI (EchoMRI 3-in-1 Body Composition Analyzer, EchoMRI, Houston TX)
Procedure: Strain selection
- Four strains were selected based on the following criteria: 1) ability to run on treadmills, 2) fat response type to voluntary exercise, 3) endurance ability (MPD datasets: McMullan1, McMullan2, McMullan3, McMullan4; all data was collected in older females).
- Selected strains were: CC002/Unc adverse fat responder, low endurance; CC027/GeniUnc adverse fat responder, high endurance; CC013/GeniUnc standard fat responder, low endurance; and CC037/TauUnc standard fat responder, high endurance.
Procedure: Exercise programs
- High intensity interval training (HIIT): Five intervals with 80% max speed for four minutes, 20% max speed for one min, and ten 30 s transitions to decrease and increase speed between the different intensities.
- Moderate intensity continuous training (MICT): Distance matched to the HIIT protocol and consists of ~43 min duration at 50% max speed.
- No exercise (NE).
- Mice complete 5 wks of exercise training on treadmills. Mice are acclimated to the treadmills for 3 days during the first week.
- After acclimation, HIIT and MICT mice complete 4 wks of training, three times a week (all training occurs in the morning).
- Compliance is tracked and mice with 50% or more non-compliant days are removed from statistical analysis. A mouse is considered non-compliant if it refuses or is not able to continue regular treadmill running despite extra stimulus from shock and/or prodding.
Procedure: Body composition
- Body composition is assessed during mornings using whole body MRI to determine fat and lean mass content.
- Measurements are taken prior to the start of the experiment and upon completion of exercise training.
- Body fat and lean mass percentages were calculated relative to body mass at each time point in every experiment. Body mass response was calculated as [(Post-mass â pre-mass)/pre-mass] x 100. Body composition percentage response was calculated as [(post-measurement % - pre-measurement %)/pre-measurement %] x 100. Body mass and composition responses were calculated for the five weeks of exercise program treatment. Negative values represent a loss and positive values represent a gain in response to treatment.
- Body weight and body weight response
- Body composition
- Fat percentage and response
- Lean percentage and response