Maximum oxygen consumption and quantification of exercise intensity in untrained male Wistar rats

This study aimed to explore a valid test protocol for measuring VO 2max in healthy untrained male Wistar rats of different ages and quantifying the exercise intensity (%VO 2max ) of running under different treadmill grades and speeds. The test protocols and %VO 2max will provide a reference for the design of exercise intensity. We tested male Wistar rats aged 4 weeks, 10 weeks, 10 months and 16 months old with three test protocols (Procedure 1 [P1], 2 [P2] and 3 [P3]) for each age group to quantify VO 2max . We analysed VO 2max , respiratory exchange ratio and test duration to determine an optimal test protocol of VO 2max for different age groups. We used the optimal test protocol to explore the changes in age-related VO 2max . Finally, %VO 2max of running under different treadmill speeds and grades was quantified. VO 2max of Wistar rats decreased significantly after the age of 4 weeks ( p