the last time i trained OD, i had a pop up on HN on both of my trainees.so logically if you train HN,you also train OD.
This is absolutely not necessarily a fact.
For example, Rebounding also trains IS and ID. ID, however, does not train Rebounding.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."