From the USA Cycling 2008 Racing Rules for Road, Track and Cyclocross

1H2. Women may enter any race for which they are eligible by age, category, and any performance requirements and may enter categorized races for men that are up to one category lower than their women’s category, or in the case of category 1 women, up to two categories lower. In addition, category 4 and 3 women who are 35 or older may compete in Masters races for all riders up to 20 years greater than their racing age, subject to other eligibility requirements.

This means that a woman with a Cat 4 license can race in a men’s Cat 5 race, and that a 36 year old woman can race in any Masters race from Men’s 35+ to 55+.

Now the UTCX Series doesn’t use licenses … we let people self-categorize; but can and will upgrade people at our discretion, which means that if any person (men or women) start dominating a particular category, then we’ll upgrade them if necessary.

But until then, I don’t like having to pull out the rule book to say that it’s okay for a someone to play with the boys. Deal with it. It’s supposed to be fun.