A FUN run for 'grown-up' iron girls has been cancelled and replaced by a Night Run.

Ironman UK has intended to introduce Iron Girl ­— a women's only 5k fun race at this year's triathlon, creating a three day festival.

But furious responses to the event, including that it was patronising to suggest women are only capable of a fun run, forced organisers to rebrand and open the race up to everyone.

Ironman UK posted on Facebook: "To our athletes and fans: We’re sorry. We’ve heard you, and we realise we’ve missed the mark on this one.

"After taking your feedback into consideration, we have decided to replace Iron Girl with the Night Run. A 5K fun run open to everyone, aged 16 and up.

"Iron Girl was not in any way intended to isolate groups or engender negative stereotypes, however we acknowledge the incorrect way in which the message was brought across. The intention of the event was to provide a 5K fun run through a supportive, energetic and empowering environment for females pursuing a healthy and active lifestyle who may want to be involved but are not necessarily interested in doing an IRONMAN event at this time.

"The event was in no way intended to diminish the achievements and capabilities of women. IRONMAN celebrates all athletes and encourages inclusive participation across all levels of competition and distances.

"We apologize again and are committed to doing better as we work to bring more racing opportunities for all."

Comments on Facebook to the original race included: "On a day a woman has not only won, but beaten the course record, in the MIXED Spine race, you decide we are only good for 5ks? This woman had a baby 14 months ago and was pumping milk at rest stops by the way.

Not only is this race condescending by its very existence, calling grown women GIRLS, really does put the boot in."

And " Wow - must inform the wife later on about this difficult running event that’s been kindly set up so she can be included in the manly world of running. I’m sure she will appreciate it, after all she only ran a marathon 8 months after giving birth" along with "5km?! As far as that?! Good grief. And there was little ol' girly me getting ideas above her station and doing a half marathon in ice and snow in the Arctic last week. Thank goodness you've brought me to my senses. I won't consider such madness again."

However, the entry change has not pleased everyone, with some saying the race should have taken place as planned.

"Next we will be changing “Ironman” to “Ironperson” I personally didn’t see the problem. Women are gradually getting more involved in the events but we are still a minority compared to men. Having an iron girl event and iron kids mean the whole family is involved in the weekend," wrote one person.

Another added: "As a strong, independent & capable woman, as an engineer and trained pilot (albeit lapsed), and as a woman who wholly believes in encouraging & supporting women's participation in sport....I am really sorry that IM has caved to public pressure. What was intended to be an inclusionary race for those who perhaps felt excluded from mass participation events, has now succeeded in potentially excluding these very people by turning this into a mass participation event. Good work. Equality has been wrongly conflated with equity. "

The race takes place on July 12 at 7pm. The course will head through the town centre into and through Queen’s Park before returning to the town centre, finishing in Victoria Square on the same finish line as the IRONMAN UK athletes.

To enter visit ironman.com/uk