Welcome to MT, I think we need more information before we click onto a random link. I don't mind surveys, I know students use them but I also like to know who it's for, what it's for and what happens to the information.
I agree with @Tez3. I clicked on it/completed it because I saw it was a surveymonkey link, and there wasn't anything particularly identifying in the questions, but more information will probably get you more responses.
The main question of the survey itself is also a very nuanced subject, that I don't think can be really grasped by just a question "it had positive/negative effect on my self-esteem".
Off the top of my head, a better option would be to create a survey focused around the rosenberg self-esteem scale, then ask standard demographic questions, and group the results by length of training (along with possibly consistency and frequency of training), to determine the a more well-rounded answer to your question.