Formal:
* Exerted oneself to the utmost: Emphasizes the physical or mental effort.
* Strove mightily: Conveys a sense of struggle and determination.
* Labored diligently: Highlights the careful and persistent effort.
* Endeavored with great zeal: Implies enthusiasm and passion in the effort.
Informal:
* Went all out: Shows a complete and intense effort.
* Pulled out all the stops: Similar to "went all out", suggesting maximum effort.
* Gave it my best shot: Focuses on the intention and effort, not necessarily the outcome.
* Put in a lot of elbow grease: Emphasizes physical effort and hard work.
Figurative:
* Left no stone unturned: Means that every possibility was explored.
* Bent over backwards: Conveys a willingness to go above and beyond.
* Moved mountains: Suggests a Herculean effort that overcame significant obstacles.
More specific options:
* Persevered: Emphasizes continuing despite difficulties.
* Toiled: Highlights the hard work and effort involved.
* Grappled: Conveys a sense of struggling with a difficult task.
* Slogged: Implies slow, steady effort.
The best synonym depends on the specific context of your sentence.