minimum of 5 complete and grammatically correct sentences

Chapter 15
Instructions
You need to answer this one question in a minimum of 5 complete and grammatically correct sentences. You must write your answer in your own words and not directly use the authors’ writings from the textbook or from some other source. You have to compose in essay format (no outlining/listing).
Question
Explain how exercise can be beneficial to persons experiencing depression, anxiety and stress? Your explanation has to address each of these three mental conditions.