Infer the meaning of the word Arduous based on the context clues provided in the paragraphs.
Paragraph 1: Even after hours of focused work, her progress barely advanced, drained from sheer effort.
Paragraph 2: Because the trail rose sharply and offered no shade, the climb pushed everyone to their limits.
Paragraph 3: While routine assignments required little strain, this particular undertaking demanded every ounce of endurance.