Q: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Schwarzenegger has admitted to using performance-enhancing anabolic steroids while they were legal, writing in 1977 that "steroids were helpful to me in maintaining muscle size while on a strict diet in preparation for a contest. I did not use them for muscle growth, but rather for muscle maintenance when cutting up." He has called the drugs "tissue building."
A:
In what year did Schwarzenegger write that he used anabolic steroid because they were "helpful"?