1. (

• strenuous

) characterized by or performed with much energy or force; "strenuous exercise" ;

2. (

• arduous ,
• straining ,
• strenuous

) taxing to the utmost; testing powers of endurance; "his final, straining burst of speed"; "a strenuous task"; "your willingness after these six arduous days to remain here"- F.D.Roosevelt ;