Yes.. Mostly. The more words in a title/article, the greater the chances of matches to Google searches. Keywords help too, and knowing what lingo people are using can help you brainstorm how to write your articles. Other factors apply too, of course. Even using several keywords, you may have trouble get views for a fitness article, as those have been done to death.
And of course, don't insert keywords just for the heck of it; make sure they flow naturally into your Hub, or you're losing more than you're gaining.