Peak Velocity as an Alternative Method for Training Prescription in Mice

Purpose: To compare the efficiency of an aerobic physical training program prescribed according to either velocity associated with maximum oxygen uptake (vVO_2max) or peak running speed obtained during an incremental treadmill test (V_{peak_K}) in mice. Methods: Twenty male Swiss mice, 60 days old, were randomly divided into two groups with 10 animals each: 1. group trained by vVO_2max (GVO₂), 2. group trained by V_{peak_K} (GVP). After the adaptation training period, an incremental test was performed at the beginning of each week to adjust training load and to determine the amount of VO₂ and VCO₂ fluxes consumed, energy expenditure (EE) and run distance during the incremental test. Mice were submitted to 4 weeks of aerobic exercise training of moderate intensity (velocity referring to 70% of vVO_2max and V_{peak_K}) in a programmable treadmill. The sessions lasted from 30 to 40 min in the first week, to reach 60 min in the fourth week, in order to provide the mice with a moderate intensity exercise, totaling 20 training sessions. Results: Mice demonstrated increases in VO_2max (ml·kg^-1·min^-1) (GVO₂ = 49.1% and GVP = 56.2%), V_{peak_K} (cm·s^-1) (GVO₂ = 50.9% and GVP = 22.3%), EE (ml·kg^-0,75·min^-1) (GVO₂ = 39.9% and GVP = 51.5%), and run distance (cm) (GVO₂ = 43.5% and GVP = 33.4%), after 4 weeks of aerobic training (time effect, P < 0.05); there were no differences between the groups. Conclusions: V_{peak_K}, as well as vVO_2max, can be adopted as an alternative test to determine the performance and correct prescription of systemized aerobic protocol training to mice.