Running speed and maximal oxygen uptake in rats and mice: practical implications for exercise training

Area of Science:

• Exercise physiology
• Animal models of disease

Background:

• Reliable experimental models are vital for understanding exercise's role in lifestyle-related diseases.
• Individualized training intensity, often measured by maximal oxygen uptake or heart rate, ensures reproducible results but is costly and time-consuming.

Purpose of the Study:

• To evaluate if maximal treadmill running speed can sufficiently control exercise intensity in rodent models.
• To determine the accuracy of using running speed versus direct oxygen uptake measurements for optimizing endurance training.

Main Methods:

• Analysis of combined data from six studies involving rats and mice.
• Correlation analysis between running speed and oxygen uptake during ramp protocols.
• Assessment of changes in maximal oxygen uptake and running speed following high-intensity aerobic interval training.

Main Results:

• A strong correlation was observed between running speed and oxygen uptake in rodents.
• Endurance training led to improved work economy, indicated by a steeper slope in the speed-oxygen uptake relationship.
• Maximal oxygen uptake increased by 40-70% after training, with a parallel rise in the speed at which oxygen uptake plateaued.

Conclusions:

• Maximal treadmill running speed shows potential for assessing exercise intensity in rodent training programs.
• Direct measurement of oxygen uptake remains the most accurate method for setting exercise intensity and optimizing endurance training in rats and mice.
• Running speed can serve as a supplementary measure to ensure targeted exercise intensity.