After Pedro had breakfast, he went for a run. Identify at least three energy transformations that had to take place to allow Pedro to complete his run. Then use evidence to support the claim that energy in this system was conserved as it was transformed.

I tried my best to answer.

1) Chemical to mechanical (calories -> muscle contractions)
2) mechanical to mechanical (muscle -> motion)
3) mechanical to thermal (motion -> heat from the body causes sweating)

The potential energy is stored in the body chemically (via food). That potential energy is then released when the body is put in motion.