Apronghorn, the fastest north american animal, is capable of running for at 18 m/s (40 mph) for 10 minutes. the time limit isn’t because the pronghorn runs of energy, it’s because the pronghorn’s temperature rises, and it must stop to cool down. why does the pronghorn’s temperature rise during the run?

Explanation:

The increase in the body temperature of pronghorn, the fastest North American animal, results from the chemical energy of the pronghorn converting into kinetic energy with efficiency less than 100%. The remaining energy is converted into heat energy. Thus, raising the temperature of pronghorn.

Due to the chemical energy it gains both kinetic and heat energy.