Adjective : a strenuous afternoon of hunting. ,To think deeply is a strenuous task. ,a strenuous person; a strenuous intellect.    From Dictionary.com. 

Atween times we must rest, relax and recuperate the waste that strenuosity makes.    From Wordnik.com.  [Evening Round Up More Good Stuff Like Pep] Reference

The building is rather modern in appearance, suggesting comfort rather than strenuosity.    From Wordnik.com.  [The New York and Albany Post Road From Kings Bridge to "The Ferry at Crawlier, over against Albany," Being an Account of a Jaunt on Foot Made at Sundry Convenient Times between May and November, Nineteen Hundred and Five] Reference

The work of the reformer inevitably degenerates into the mere strenuosity of the campaign.    From Wordnik.com.  [The Poet's Poet : essays on the character and mission of the poet as interpreted in English verse of the last one hundred and fifty years] Reference

The strenuosity of the life, the nervous excitement alternating with ennui, the lack and improper times of sleep, the lack of rest and particularly of restful occupation, the not infrequent use of alcohol in injurious amounts, are all factors calculated to make a defect operative.    From Wordnik.com.  [Disease and Its Causes] Reference

And his lazy acquiescence in life was peaceful and inviting to my own strenuosity.    From Wordnik.com.  [The Heart's Kingdom] Reference

I am losing pounds daily in the process, but make up in pride over my strenuosity.    From Wordnik.com.  [A Woman Rice Planter] Reference

The struggle to compass big salaries for the pastorate has advanced into strenuosity.    From Wordnik.com.  [Country life in Georgia in the days of my youth,] Reference

Roosevelt had the same characteristic but he displayed it with much more animation and strenuosity.    From Wordnik.com.  [An African Adventure] Reference

Pluralistic strenuosity suffers no such restraints; it recognizes no obstacle that cannot be overcome.    From Wordnik.com.  [The Catholic Encyclopedia, Volume 12: Philip II-Reuss] Reference

He put a curb on strenuosity; started to study the French temperament; he began to see why he had not succeeded.    From Wordnik.com.  [The War After the War] Reference

Perhaps the other extreme, so characteristic of our southern African friends, is no better, yet it has a charm absent in the strenuosity of mere eagerness.    From Wordnik.com.  [The Advance of English Poetry in the Twentieth Century] Reference

Such people, and those who care for them, must not make the mistake of thinking that rough handling, strenuosity, will cure what is apparently a fixed character.    From Wordnik.com.  [The Foundations of Personality] Reference

The garden has been weeded, replanted, trained, clipped and garnished, and my arms are as husky and strong as a boy's and my nose badly sunburned from my strenuosity with hoe and trimming scissors.    From Wordnik.com.  [The Tinder-Box] Reference

Apostate and his apostasy; and half the rest, that there was an end of this terrible strenuosity, this taking of the Gods (good harmless useful fictions -- probably fictions) so fearfully in earnest: I wonder how many there were to guess how near the end of the world had come?.    From Wordnik.com.  [The Crest-Wave of Evolution A Course of Lectures in History, Given to the Graduates' Class in the Raja-Yoga College, Point Loma, in the College-Year 1918-19] Reference

And added to the strenuosity of the laying of my plans for at least a year's absence, I had to help father make his arrangements for a six months 'stay in Washington, for he had accepted the President's appointment on the Commerce Commission, and night and day he was at his library desk.    From Wordnik.com.  [The Heart's Kingdom] Reference

Diogenes, "and thus did strenuosity pay its tribute to self-sufficiency.    From Wordnik.com.  [Little Journeys to the Homes of the Great Philosophers, Volume 8] Reference