You don't need to read or understand them all, just what you're looking for when you need it
for sports in general:
muscular anatomy, human physiology, physiology of effort, gastrointestinal tract, endocrinology (the axes of interest)
then add bodybuilding:
W. llewelyn 11edit AAS, nutrition timing, pharmacology of chemical enhancement (roidz etc)
finally add optimal health:
orthomolecular nutrition, diverse health books (..too many to sum)