Sonya Liggins-Walters of Invercargill, says LGB students are bombarded by casual derogratory language.

Schools are being urged to crack down on homophobia as a landmark study finds gay New Zealanders are struggling to come to terms with their sexuality due to negative experiences in physical education class.

A damning international report has uncovered rampant homophobia in New Zealand sport, and found many young gay, lesbian and bisexual (LGB) students had their first bad experiences with homophobia during "PE" class.

Having an ally in a leadership role at school was crucial for young gay people, said teacher Sonya Liggins-Walters.

She struggled with her sexuality as a gay teenager in Invercargill, and said better training for teachers around supporting LGB students would make a huge difference.

"If students can see they have allies or support in the school they can trust, and they won't be judged for anything, it's powerful. It's so amazingly powerful," she said.

"If they knew they had an ally in a staff member or a coach or a referee, it would be immensely powerful. It would give them so much more strength in staying with the sport."

The Out on the Fields study released today found even casual homophobia could have damaging long-term effects, and could prevent LGB students from coming to terms with their sexuality.

Dr Grant O'Sullivan from Melbourne's Victoria University, who was part of an expert panel on the international study, called for teachers and schools to be more inclusive.

"The issue with PE classes is that it's often the kids' first experience with sport, because it's compulsory. If it's less than stellar and if there's homophobia involved while kids are still working themselves out, it can put people off," he said.

"They're hearing either direct homophobia, or more likely casual homophobia, which sends the message that if you were 'out' you wouldn't be welcome."

Openly gay Olympic speed skater Blake Skjellerup said he quit playing rugby as a child because of the "constant homophobic bullying". Competing in an individual sport made dealing with his sexuality easier, he said.

He agreed the All Blacks should lead the issue, and praised Australian rugby star David Pocock, who has been an outspoken critic of homophobia and recently called out his opponents for using homophobic slurs on the field.

"I think this study clearly shows that homophobia in sport needs to be taken much more seriously in New Zealand," he said.

"I think the All Blacks and New Zealand Rugby could play a very powerful leadership role by supporting and helping gay kids struggling with their sexuality."

The 'Out on the Field' report is the largest of its kind ever conducted, surveying nearly 9500 people across New Zealand, Australia, USA, Canada, UK and Ireland.

New Zealand performed dismally in the study, which found an overwhelming majority of LGB New Zealanders saw team sport environments as homophobic and unsafe.

They were more likely to hide their sexual orientation from teammates, coaches and officials due to fear of discrimination than any other country surveyed.

It rings true for Alister, a college rugby player turned referee who battled homophobia as a closeted gay man in New Zealand's heartland.

His full name can't be published because he has a sensitive role within the police, but he is now openly gay after years of hiding his sexuality for fear of discrimination.

He played college rugby in Manawatu, and said the small town environment fostered homophobic attitudes that made him fear coming out.

"I used to sit at school and watch them pick on the openly gay ones, so I just thought, 'nah'," he said.

"Rugby in particular is a very weird sport for homophobia. And I've worked at all levels and seen everything. The sporting environment, particularly male rugby, is a lot more homophobic than the general environment."

The report found rugby union was the sport most commonly played by LGB New Zealanders.

Nearly 70 per cent of gay men surveyed said sport was a more homophobic environment than greater society.

It got worse for Alister when he started refereeing. Players flippantly tossed off homophobic slurs without thought.

He said it made him angry - he thought back to his time as a Maori warden, where he saw young gay men killing themselves because they feared intolerance.

"I know quite a few gay rugby players who won't open up their sexuality at all. They just try and cover it up.

"A lot of my friends, they don't [come out] because of their family's religion. They see how their families see it, so that's how they think everyone else will see it."

Ryan Sanders led a "double life" when he played rugby in the ITM Cup (then the NPC).

He hid his sexuality because he feared he wouldn't be accepted, and only came out after his retirement in 2004.

He worried the same attitudes that kept him in the closet were keeping current athletes in there too.

"It's a bit depressing to see the study has found so many gay men in New Zealand still feel the need to do the same while playing rugby and other sports," he said.

He said frequent homophobic language was stifling and made him feel like coming out wasn't an option.

Derogatory slurs such as 'faggot' and 'poofter' were experienced by 87 per cent of New Zealand gay men, the second highest result in the survey.

For the issue to truly gain traction, one thing needed to happen - the All Blacks needed to step up and come out against homophobia in sport.

"That's the magic key, I think. Undoubtedly that's what needs to happen. It would just be a huge leap forward, I can't think of anything more important really.

"I think the way things are going now with marriage equality and everything else going on it would be very timely."

FEAR OF NAME CALLING BEHIND CHOICE OF SPORT

Sonya Liggins-Walters lived in fear. She worried about the names; she didn't want to be called "butch".

The Invercargill teacher, now 36, kept herself out of team sports because of what she thought might happen.

"It wasn't out of fear of being abused or the violent side of things, I just didn't want people to call me names. I didn't want people to acknowledge it," she said.

"It was more about my perception of what I thought would happen."

As a teenager, she didn't play netball or rugby like the other girls. She started the lonely pursuit of Olympic weightlifting, a sport in which she represented New Zealand internationally.

"It was a strange thing for a teenage girl in Invercargill to pick up," she said. "But in the individual sports it was easier to control the situations."

Now a teacher, she fears the problem is worse than ever before.

"I worry more about kids today than I do about what we were like. Now it's a bit different.

"Nowadays you hear statements like 'that's so gay' used in a derogatory way. There's a permissiveness about their phrase. The reality is words like that… just that continual use of the derogatory nature of that word, it's sad. It's really sad and it's isolating."

When she was young, the intolerance was in her head. She could hide from it.

For kids today, who were never far away from a communication device, they had to face the problem head on.

"Kids are bombarded with a whole heap of stuff every day. If you're on the edge of a peer group anyway, things like the casual derogatory language… your ears just prick up and you're like 'okay, maybe I won't say anything today.'"