Biology Experiment Associated with Running

[stopme]

I have an experiment for my biology class which i want to relate to human performance since my professor is a physiologist in this field. I really want to do an experiment which involves running but i cant think of any cool, eye opening topics. I have wireless heart rate machines, ekg machines, blood pressure machines, electromyographs, metabolic measurement carts, computerized spirometers, and pulse oximeters at my disposal...also numerous labs. Any suggestion would help.

[mith]

test gatorade's electrolytes.