Final answer:
The author's purpose is to inform the reader about the importance of stretching before a race.
Step-by-step explanation:
The author's purpose in writing the sentence is to inform the reader about the importance of stretching before a race in order to keep muscles limber. This information helps the reader understand the preparation involved in running a race and how it can contribute to a successful finish. The sentence serves as a reminder that stretching is a crucial part of the race preparation process.
Learn more about author's purpose in writing