You need to place keywords in the headers. The keywords will help the rankings. It will not be a super success, but it will have an effect. The search engines respond best to on-page strategy, therefore this is an element not to miss.
The indexing tools will search for keywords to get you in the search engine. They will look at the headers. The same rules apply though. You still need the headers to make sense when you use keywords. You can’t have something that is keyword stuffed because the consumers are going to recognize this and penalties can ensue from the search engines. The density should be normal. Don’t use repetition to spam the search engines and therefore your potential clients.
For rankings the headers need to be in a specific format. The rankings are not going to like something that is too large or that doesn’t make sense. Make sure that you provide an appealing look for better rankings. There are certain font sizes recommended by search engines that you should stick with. They need to be appealing overall.
Your best approach to the whole scenario is offering the primary keywords in the headings and one or two secondary. The eyes will track the keywords just as the search engines will. It also helps to point out the key points on the page.