The phrase "fierce effort" is correct and commonly used in written English.
It can be used to describe a determined or intense effort someone has put in to achieve something. Example: Despite facing numerous obstacles, the team made a fierce effort to win the championship.
The Inter keeper was then in action again, this time getting down well to keep out Kwadwo Asamoah's fierce effort.
After Bettinelli's blooper Sunderland grew in confidence, especially Álvarez, who slalomed in from the right and unleashed a fierce effort.
(You can find the same compositional severity, the fierce effort to restrain beauty, in Bresson and Buñuel).
And somber rescuers recalled the fierce effort to save the children and firefighters after the buildings had collapsed.
Moore shows off the graceful ease with which she can work hard; Aniston shows off the fierce effort with which she achieves graceful ease.
Guthrie was all on his own midway into the Ipswich half and beat Ipswich Scott Loach with a fierce effort which went over the keeper's head.
But Phillips is pushing these practices to new depths in its fierce efforts to dethrone the duopoly at the top.
Gordon was forced into two saves from fierce efforts though, the second from Agim Ibraimi before Dare Vrsic blazed the rebound high and wide from an angle.
Executive pay continues to skyrocket despite years of criticism by corporate governance gurus, fierce efforts by unions to temper compensation and calls by politicians to regulate pay.
By contrast, fierce efforts by Mr. Santorum to carry the popular vote in Ohio, even if successful, could win him just a few more delegates than Mr. Romney because they are allocated proportionally in that state.
Chris's fierce efforts at self-liberation, and a self-image that's deeply imbued with the memory of violence, make for a rhapsodic, visionary, yet harshly implacable drama.
