"Taken together, the sources I have consulted so far on my research topic reveal

Taken together, the sources I have consulted so far on my research topic reveal that the subject of the use of hGH in sports is widely known, yet some people feel that it is not truly a performance enhancing drug because their studies show that it only adds lean mass to a person's body, not muscle, and it does not help them perform better. This is refuted though by a lot of other sources I have looked at, and by the approach that professional athletics is taking on this subject. This is a good they say, I say issue, because some research shows that hGH does not have an effect on one's performance, other studies, professional athletics, and people who have used it seem to believe that it is. I do not have any research done on the question of the psychological reasons why athletes turn to performance enhancing drugs, because that is a section that I am going to use my personal experience of being an athlete to write.