There are multiple reasons someone may develop anorexia. Sometimes it is because of stress or anxiety. Most commonly, it is the constant need to feel as if they weight too much and need to remain slim.
This isn't a full essay but there is some helpful information about Backstrokes. (Tip: Make sure to paraphrase the info you use)
The Backstroke, also known as a back crawl is one out of four swimming styles you can use. Out of the four swimming styles, the backstroke is the easier as far as breathing but maybe be harder to swim hence the fact you can't see. Backstrokes are great for strengthening your upper body and helps tighten your core according to PopSugar. In order to master this style of swimming, you have to have balance. The backstroke engages all of your core.