effort vs straining

effort and straining both are nouns.

Word	Noun	Adjective	Verb	Adverb
effort	Yes	No	No	No
straining	Yes	Yes	No	No

As nouns, straining is a hyponym of effort; that is, straining is a word with a more specific, narrower meaning than effort:

effort (noun)	straining (noun)
earnest and conscientious activity intended to do or accomplish something	the act of distorting something so it seems to mean something it was not intended to mean
use of physical or mental energy; hard work	an intense or violent exertion
a notable achievement
a series of actions advancing a principle or tending toward a particular end

effort (adjective)	straining (adjective)
	taxing to the utmost; testing powers of endurance