| Weigh mice before and after treatment
||Assess body composition before and after treatment
||Collect metabolic measurements and measure food and water intake before and after treatment
||VO2, VCO2, RER, activity, food weight, water volume, heat production
- Treadmill (Exer 3/6, Columbus Instruments, Columbus OH)
- Calorimetry system (PhenoMaster, TSE Systems, Chesterfield MO)
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: Indirect calorimetry
- Indirect calorimetry is assessed prior to any training and then again after the training period.
- To acclimate to single housing, mice are individually housed for 24h prior to the start of the indirect calorimetry.
- Mice are then individually housed in calorimetry cages for 24 hours and data are recorded every ~50 min for each calorimetry cage.
- Food intake is calculated as the differential between baseline and post exercise food weights (g). Adjusted food intake is calculated as the food intake relative to the baseline body mass.
- After, mice are returned to their assigned group housing.
- Oxygen consumption
- Carbon dioxide output
- Respiratory Exchange Ratio (RER)
- Activity (beam breaks)
- Food weight
- Water volume
- Heat production