A team of 32 is undertaking an expedition called Operation R.I.D.E which is seeing them cycle the length of New Zealand - about 2440km.
The team includes UK, NZ and Canadian injured veterans. Some have physical ailments while some have forms of PTSD.
Rotorua's Tui Keenan said it had saddened her the team had to pay for most of their accommodation and food on the expedition.
"And being ex-navy I'm obviously connected to them through that experience.
"These people get forgotten all the time, and I just feel honoured to host them and have this facility available."
She thanked the Harvest Centre for not charging the team to stay there.
Having just finished filming a hunting show, she also provided the team with some Kiwi food when they arrived and organised a soak at the Polynesian Spa.
The also went to a Rotorua shooting range.
The charity is close to the heart of Polynesian Spa sales and marketing co-ordinator Hayley Greville-Mattinson who is also ex forces (UK RAF).
John Le Galloudec has come from the United Kingdom for the ride.
He said the scenery in the South Island was epic and he had enjoyed the camaraderie.
Le Galloudec said the charity was a great idea because it was helping people both physically and psychologically.
He left the UK army in 2012, but was injured in 2007 in Iraq.
David Benfell is a Kiwi but served in the British Army, leaving in 2012.
He said it had been cool getting together with people who had the same experiences.
"When people leave the military you've gone from being a member of a social, tight-knit family, and when you leave you stay in touch but it's not the same, so events like this are great for your mental wellbeing."
Tyler Christopher, who left the British Army in 2014, liked the socialising of the event.
