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Online marketing is all about where you want to invest your limited time and resources. Targeting the single words you suggest is not likely to return the targeted traffic you are seeking. You would be better served using the phrases that your potential clients are using instead of trying to "beat the Jones's" to the top of the SERPS.
In your example, though, I could see "sports nutrition" as being somewhat useful - perhaps the opportunity exists to promote your targeted brands to a wider audience. If you aren't paying for clicks, it would seem like even a low conversion rate could be profitable.