I don't find domain age a major hurdle. If you keep you keywords relevant (especially in your domain name) and your page rank up you should do fine. As the fitness industry is fairly competitive you may need to target some longer keyword phrases that they aren't targeting. Also, you may wish to start a satellite site that has the domain name with the keyword in it. I can't stress enough how incredibly important the keyword in the domain name can be. 

Thank you for your input Scott.  I have my main keyword in the name of the domain, and I'll continue to backlink it.

I am willing to take heat for this statement but I have come to believe this may be the very holy grail of SEO. Since it is related to your question, I will share the knowledge. If you use MS Competition Analysis feature, you will see that there are many domains that are less than 1 year old, or even just a couple years old outranking 12 and 15 year old sites.

I see it every day.

Age has little to do with competition directly, even though it is marked 'red' as a hurdle in the Competition Analysis Module, it's something to consider but not your biggest threat. I will tell you what is though, and this is the holy grail I speak of, I believe the single most important SEO factor that outweighs ALL other factors is BACKLINK AGE.

Yup, I said it and I will take the heat for it. So James, if it is a 15 year old site, no biggie, check their backlinks. 15 years ago SEO wasn't really on many people's radar so maybe they have been SEO-ing for the last year and their backlinks are a year old.. couple years maybe. It's the 15 year old backlink that is a doozie to beat. Might as well be a do follow from a PR 10 site on the home page haha :)

So, don't sweat the DA number too much.

Leif

Dear Leif, I've been told over and over that backlinks are everything. So how doe you check another site's backlinks. I also agreee that well placed keywords and consistent updates count for a lot. my little art quilts blog jumped over the biggies in the industry because of the above and my blog is on WordPress.og, so all clicks count for my SEO.

Nancy

Hiya Nancy that's great about your quilting blog and it shows that there is more to rankings than just one factor. There are a few ways to check backlinks of a competitor. One is the SEO Competition module of Market Samurai, that is, if you own it. A second (and what is used inside of Market Samurai is Majestic SEO ->http://www.majesticseo.com/ however their interface.. leaves a little to be desired. What I have been LOVING is SEO Site Explorer ->http://www.opensiteexplorer.org/

Whats cool there is you can compare you site and 5 other sites side by side. It shows you everything at a glance and on the same page, shows you where your weakness is , their weakness, their strength all that. Check it out please !

Leif

Regardless of the extent to which domain age affects rank, once all of the on-page factors have been optimized correctly, off-page factors are the only thing left to do, which, in a word, means backlinks.  Quality backlinks are key, but so is quantity, and the ratio between the two has to look natural to the search engines.  Also, based on my own experience, the ratio of do-follow links to no-follow links matter as well.  I know that some people here may disagree with that last statement, but that has, in fact, been my own experience.