strenuous
1. [ adjective ] characterized by or performed with much energy or force
Examples:

"strenuous exercise"

Related terms: energetic
2. [ adjective ] taxing to the utmost; testing powers of endurance
Synonyms: straining arduous
Examples:

"his final, straining burst of speed" "a strenuous task" "your willingness after these six arduous days to remain here"- F.D.Roosevelt

Related terms: effortful
Similar spelling:   strenuously
  Sturnus
  strenuosity
  sternpost
  Starns
  Sterns
  Storino
  Sternotherus
  Starnes
  Stearn
  Sterna
  sterne
  Styron
  Streng
  strewn
  sternness
  Sternisha
  storing
  Starner
  Stormer
  sternly
  Sterner
  sternal
  strengthen
  Stermer
  Sturman
  styrene
  sternum
  staring