Can you explain to me what happens to the energy when you do work?

Question

thanks

Answer 1

When I do work, like running 1 mile in less than 4 minutes, you see heavy breathing, faster breathing, sweating, much higher heart rate, muscles tired, etc. So the work I expend in running that mile shows up as increased CO2 in the air, faster metabolism, aching muscles, etc. Here is a site that explains it much better than I.
http://physics.bu.edu/~duffy/py105/Energy.html

Answer 2

thank you @DrBob222