He lifted the boulder, but not without heavy exertion.
you can not win without exertion . Your highest exertion is required.
Strenuous is an adjective. Strenuous means requiring or using great exertion.
The base word of "strenuous" is "strength."
The workout was quite strenuous.
Strenuous describes hard and extended physical exertion or exercise.
Too much strenuous exercise can result in jury.
The strenuous exercise made my muscles ache.
give me the answer
"Illustrate" is a word that means to give an example or to make something clear by using examples.
Give me a sentence on word brood
Endeavour
No, it's an adjective (word describing a noun)
Difficult, tedious, strenuous.