No, it's an adjective (word describing a noun)
The nearest 'connected' verb would be 'strain', i.e. endeavour. There is no original verb - it only exists as an adjective or adverb.
Strenuous is an adjective. Strenuous means requiring or using great exertion.
Strenuous exercise makes me tired.
The base word of "strenuous" is "strength."
Strenuous exercise is good for your heart.
The workout was quite strenuous.
According to the Merriam-Webster thesaurus the word challenging has 30 synonyms. The more commonly used ones include backbreaking, difficult, killer, strenuous and sever.
Strenuous describes hard and extended physical exertion or exercise.
Too much strenuous exercise can result in jury.
The strenuous exercise made my muscles ache.
A vivid verb for "work hard" is "toiling." It conveys a sense of strenuous effort and labor, often associated with long hours and perseverance. Other options include "grinding" or "striving," which also emphasize intense dedication and relentless effort toward achieving a goal.
He lifted the boulder, but not without heavy exertion.you can not win without exertion . Your highest exertion is required.