strenuous strenuous /ˈstrɛnjuːəs/

adjective

1. () Characterized by or performed with much energy or force  ( strenuous )
   characterized by or performed with much energy or force
    Strenuous exercise
   strenuous exercise
   
2. Taxing to the utmost; testing powers of endurance  ( arduous , strenuous , straining )
   taxing to the utmost; testing powers of endurance
    His final, straining burst of speed
   his final, straining burst of speed
    A strenuous task
   a strenuous task
    Your willingness after these six arduous days to remain here
   your willingness after these six arduous days to remain here