General:
* Active
* Diligent
* Energetic
* Hardworking
* Industrious
* Motivated
* Productive
* Vigorous
* Zealous
Focused on Effort:
* Assiduous
* Conscientious
* Dedicated
* Persistent
* Tenacious
* Tireless
* Unflagging
Focused on Speed:
* Agile
* Efficient
* Swift
Focused on Skill:
* Competent
* Proficient
* Skilled
Antonyms of Lazy:
* Busy
* Energetic
* Active
* Industrious
* Alert
Phrases:
* Go-getter
* Workaholic
* Driven
* Ambitious
The best word to use will depend on the specific context. For example, "diligent" might be a good choice for describing someone who is careful and thorough in their work, while "energetic" would be better for someone who is full of enthusiasm and vitality.