Do I need to go to the gym and workout?

If the singular term ends in -us, the plural is usually formed by changing the ending to

Weight management is one benefit of participating in sports which sentance is true regarding weight management

Investigator a has biological specimens that are coded and linked to identifiers of the source individuals. investigator a provides the specimens to investigator b but does not provide the individual identifiers. investigator b agrees not to re-identify the source individuals. is investigator b's research using the biospecimens human subjects research according to the definition of human subjects research in the federal regulations?