Matt Heath: Come together, right now, undie-free...

Go on, put it all on the line. Photo / Getty Images

Sense of community on this national day is a true joy.

It was National Freeballing Day on Thursday. A day when Kiwis from all walks of life choose to not wear underwear. Not for charity, not to make a statement, not for sexual reasons, just to come together as a community.

It was huge. On my morning radio show I received over a thousand calls from people who wanted to share with the country that they weren't wearing anything under their pants. Males, females, mums, dads, students, baby boomers and school kids. Rich and poor.

People of different races, creeds and cultures. People who weren't wearing anything downstairs and wanted the world to know. Ringing in, proudly declaring their family name, their home town and the fact they weren't wearing any knicks.

"Hi I'm Matt Heath from Dunedin and I'm freeballing."

Kiwis' reasons for not wearing undies were as varied as their backgrounds. Some suffer terrible chafing, others just can't get comfortable down there, others like the feeling of cold June air buzzing around their downstairs. Max Key was clearly doing it as a tribute to Zoolander.

Some wanted to be part of a movement bigger than themselves. A national breaking-the-shackles day. Undies are a huge problem for men. We must choose either to run a net or go so baggy it's like we have nothing on anyway. In the end, there is far more adjustment needed when packing underwear than not. So why pack?

As luck would have it, I found myself in Greymouth for National Freeballing Day. There is a chilly, damp wind that blows down the Grey Valley. They call it "the barber". It cuts right through you. You can see it coming as a mist which adds a visual aspect to its awesome chilling power. When you're facing the barber generally you want as many layers as you can get.

But it's an important day and I did my duty. I stood in the middle of Mawhera Quay and faced the barber head on. It was heartwarming seeing so many Coasters join me.

There are obvious risks with freeballing. There's the potential for a Something About Mary situation for men.

Skirts can make the whole thing harder for women and there were a few incidents along these lines on the day. A few pairs of jeans that needed premature cleaning after a day without the layer of protection they normally enjoy. But for me the biggest problem is around emergencies.

That's what your mum tells you: "Make sure you have clean undies on just in case there's a fire or you end up in hospital." One caller I had on the show was hit by a car sans knicks. She ended up in hospital in a pair of health department paper undies. It's a risks/rewards situation.

If there are dangers in freeballing there are equal dangers with underwear.

Scientific evidence suggests they heat up downstairs causing count lowering.

Victorian women had a gap in the fabric to let air in. A bit of wind was seen as a good thing.

I have talked before about the joys of being part of a movement. The times when New Zealanders come together as one. National Freeballing Day is one of the best. A day when you walk around never quite sure if your fellow Kiwi is wearing anything down there or not. When you find out they aren't you are united in a very unique way.

It's a great day and a positive thing for the country. Long may it last.