На задали ответить на вопрос: why do people do sport? начинать надо с этого: 1) sport ) и 2) peple go in for sports )

1) Sport is the extension of your life. Also sport helps develop your muscles, train the heart and so you can live longer.
2) people go in the sport for various reasons: some people like to play sports running, someone wants to lose weight, some people want to train your heart and health. Depends on a person.