Martina Navratilova: 'I cried for a minute, then I knew I had to put the wheels in motion'

A 53-year-old woman recently diagnosed as having breast cancer might reasonably be expected to take it easy, slow down, take stock. Not Martina Navratilova. In the past couple of weeks she has been to Minneapolis, Atlanta, New York, Hawaii, London and Paris; she has also competed in a triathlon, played ice hockey, and played Lindsay Davenport in an exhibition tennis match. Somewhere in the middle of this frenetic schedule, she had a lumpectomy. Soon she will undergo radiation treatment. But her lifestyle will not change. "I'll eat a little less fruit because cancer loves sugar," she tells me. "But you need to be active during radiation."

Sure, but there is ordinary active and Martina active. I catch up with her – no easy task – in a tough, working-class area of east London. It is the day after her speech to the gay rights organisation Stonewall, who invited her to Britain, and now she is embracing a different cause, representing the Laureus Sport For Good Foundation at a project in Woolwich called "Fight For Peace", where youngsters are taught self-discipline through boxing and martial arts.

The indefatigable Navratilova takes her causes seriously. In December she will lead a climb up Mount Kilimanjaro to raise funds for Laureus. If zest for life were enough to zap cancer, she wouldn't need the radiation.

But she does. She was at home in Aspen, Colorado, when she got the results of her tests. "When I heard 'positive' it was a split second before I realised that positive was a bad thing. I was told that I would need either a mastectomy or a lumpectomy, either chemotherapy or radiation, and I'm, like, 'Jesus'. That's when I cried for about a minute. Then I'm like, 'OK, what do we do? Let's put the wheels in motion.'" She knew how shocking the news would be to a world that sees her as the very embodiment of fitness. "I won my last Grand Slam title one month short of my 50th birthday. I'm the poster child for health and fitness. But it just goes to show that cancer doesn't pick according to that. Otherwise I'd live to be 200." A short laugh. "Which some people might be upset by."

Characteristically, she made her condition public in the hope that other women might benefit. "A lot of people don't go for these mammograms because they're scared they'll find something. I'm, like, if there's something there I want to know now, not a year from now. The lumpectomy took it all out, but now I need radiation to ensure it won't come back, and mammograms every six months. If it does come back you'll hear about it, but I don't need to chronicle it any more. I have already gotten so many emails and Facebook posts from people saying, 'You reminded me I need to go [for a check-up]', or 'I went the day after I heard about you.' That's very gratifying."

And so cancer awareness joins all the other "awarenesses" that Navratilova has used her colossal fame, and not a little of her huge fortune, to promote. I ask her whether she thinks sport has reached anything like its potential as a force for good. "There is always more to do, but it's a great tool for change. Sport is always ahead of where the laws are, where politics and prejudices are. It has always bridged the gap between Jew and Muslim, black and white, straight and gay, religious and non-religious, Communist and capitalist, because as athletes we don't judge by those criteria. It's 'how well does she hit a forehand?' Or 'how fast can he run?' That's the beauty of sport."

Nicely said, but has sport bridged the gap between straight and gay, the cause closest to her heart? Homophobia abounds, witness the anomaly that on the stage where only sporting prowess is supposed to matter, no leading soccer player has dared come out.

"You're right, it's the last bastion of inequality, and organisations like Fifa are not doing enough. But then look at what the number two at the Vatican just said, equalling homosexuality and paedophilia. I'm like, 'Are you crazy?' What an insult to me as a human being. Those guys are sick. Pointing the finger without cleaning up their own house. They're just so hypocritical."

At the Stonewall dinner last Thursday she met the former Wales rugby union captain Gareth Thomas, who came out five months ago to a mostly supportive press and public. "And a rugby player, my God," she says. "That's as macho as you can get. And he's still playing, he didn't wait until after he'd retired. That was extremely brave, and I gave him a big hug. I came out when I was playing but there was a net between me and my opponent. He's pretty vulnerable out there, but he has earned the respect of his peers and he's helped kids. Before, if you played rugby then you were straight, because fags don't play rugby. And it works the other way. There are girls who don't get involved in sports because they don't want to be called dykes. Homophobic taunting hurts straight kids too."

Navratilova announced her homosexuality in 1981 when asked to confirm or deny the rumours that she was a lesbian. "I couldn't lie, but it led to some very demeaning articles. They wrote that I would pick my doubles partner so I could look at her bum when I was serving and she was at the net, that kind of stuff. It seems astonishing now, so I guess we've made progress."

And so to tennis, the one subject conspicuously absent from our conversation so far. The 2006 US Open mixed-doubles title with Bob Bryan, was – and no matter how often you say it, it still astounds – the 59th Grand Slam title of her career. When I first met her earlier that year she told me that she would not play after her retirement from top-level competition, but she does. "I play to stay in shape, but also I'm still learning," she says. What on earth could there be left to learn? "New angles, new techniques. I've recently changed my forehand grip."

If she were made the game's benign dictator – and tennis could do a lot worse – she would make some fundamental changes. "I'd have faster surfaces and one serve. That way we'd see more balls in play. The serve, especially in the men's game, is way too influential. And the game in general is too skewed in favour of baseline play, because surfaces are slower and the rackets enable you to put so much spin on the ball. You don't have to pass people, you can just dip it at their feet, which means they have to volley up and that makes them a sitting duck. I can't serve and volley nowadays and I'm the greatest volleyer there was, so something's not right."

Does she not, though, bear some responsibility for turning tennis into a power game? Women's tennis 30 years ago had never quite seen the like of Navratilova. "Yes," she says, "but that was because I was strong. Now, the rackets do the work for you. They could make them them smaller, or ban nylon and play with gut again to cut down on the spin and get people to the net more." With her influence, I venture, she might even get these things done. She smiles. "But that would be a full-time job and I don't want a full-time job."

Besides, tennis is doing OK even with two serves and nylon strings. Other causes need her energies more. "I speak out where I feel the need," she says, "which has cost me plenty, but it makes me feel good and most of all it makes a difference in other peoples' lives. At the Stonewall dinner I had lesbians telling me that they felt validated when they heard my story. That stuff makes it all worthwhile."

What, though, did her fellow Czechs feel when she defected in 1975? Validated, or betrayed? "They were pulling for me, but they didn't hear much about me. The newspapers there would write about Wimbledon in detail but on the day of the final they'd stop. That's how people knew I was in the final, because they heard nothing about it. And I didn't get much attention in the States either, because I wasn't American. That cost me emotionally."

She tried to reclaim her Czech citizenship 10 years ago but, in a development worthy of The Good Soldier Svejk, her papers were lost. She finally got round to the form-filling again in 2008. "And I'm proud to be a Czech again. Right now the Communists are getting more power, so in some ways it's going backwards but it's still a country I can be proud of. And I'm happy to be an American too."

She was an outspoken critic of her adopted country, however, during the presidency of George W Bush, and gives a wry smile when I remind her. "They said, 'If you don't like it here, go back to the Czech Republic'. I said, 'I do like it here, that's why I'm speaking out'. Of course, if I said something bad now about Obama, they'd be saying, 'Yeah, you're right'. It's the same people."

Nevertheless, her enormous popularity now would have seemed like an impossibility to the young woman who felt as if she didn't belong either to the country that bore her, or to the one that took her. And it didn't help that for years her principal rival was that all-American paragon of femininity, Chris Evert.

"Yes, I didn't fit on so many levels. I came from a Communist country, I had an aggressive playing style, and on top of that I was gay, while Chris was the perfect girl- next-door. There couldn't have been a greater contrast, in fact before we played a final in Florida once one paper wrote it up as good versus evil. That was the headline: 'Good versus evil'." How did she overcome that? Was it just that, as she aged and Steffi Graf emerged, she became more vulnerable on court? "Partly that. But I think they got to know me. I am jealous of Federer and Nadal now, getting a chance to talk to the crowd after a match. I had no chance to do that, so I was not loved as much as I should have been, or respected at least, whereas now I get too much love and respect, more than I deserve, so it has evened out. Now I feel I can get away with anything. Then, I could get away with nothing. I once gave my opponents several points because the line calls were bad, and next day there was a picture of me gesticulating, and a caption: 'Navratilova repeatedly complaining about line calls'. Now it would be, 'Martina, such a good sport'."

She is laughing, but the laughter hasn't reached her eyes. Maybe the hurt runs too deep. Whatever, it is now time for her to leave the UK. She is expected in Paris but her flight is grounded so a car is waiting to take her to Dover. On the possibility that she might have to postpone her scheduled return to Colorado she is philosophical. After all, what kind of challenge is a cloud of volcanic ash when you're Martina Navratilova?

In December, Martina Navratilova will climb Mount Kilimanjaro to raise funds for the Laureus Sport for Good Foundation. There are limited places to join her. See www.laureus.com/get-involved/mount-kilimanjaro-climb