How fit and improved smokers who quit become versus those who didn’t quit ?

Order Description
My research question is about how patients smokers improved who quit smoking versus those who still didn’t quit. This research is in Cardiorespiratory care field. How
their FEV1 and their respiratory fitness levels become when they quit versus those who didn’t quit. I will be testing patients who smoke and they will be 45-65 years
old. I will do 6 minutes walking test and test their FEV1. You will do an introduction, methodology, and a literature review. You need to find different articles that
talk about different criteria that I just mentioned. Like testing FEV1, how do they improve, 6 minutes walking test, etc and do a literature review on each article you
use. The articles must be related on my subject.