The Indian heat is searing in the gym when the power goes out. A physio hurries over with an emergency lamp and boxing star MC Mary Kom resumes battering the punchbag.
It's hardly an ideal training session for an Olympic hopeful, but then glory never came easily for Kom.
From her beginnings as a poor farmers' daughter in a remote and troubled corner of India, "Magnificent Mary" has fought her way up to become five-times world boxing champion.
The mum-of-two is now tipped as her country's best bet to win gold at London 2012 -- a position few could envisage when she began learning to box.
"People were discouraging me, saying in India there are not women boxers. That was my first challenge. I took the challenge, I had to prove myself," she told AFP in Pune, the western Indian city where she is currently training.
Kom -- full name Mangte Chungneijang Merykom -- was born 29 years ago in the northeastern state of Manipur, the eldest of four to parents who struggled to support their family through working on the fields.
Growing up with a love of action movies, Jackie Chan and her hero Muhammad Ali, the young Kom realised that her passion for sport could provide a path out of poverty if she made it big.
"So I left studying and focused on training," she said. "I did everything in athletics: running, discus, javelin, so many. I can do everything."
When she heard that women's boxing would be included in the Manipur state championships in 2000, she took to the ring and won the tournament just four months later.
She tried to keep her new activity quiet from her parents, but when her victory was revealed in the local newspaper, her sceptical father summoned her for a talk.
"He was worried about me getting injured and that he couldn't support me financially. But finally I convinced him, and at the last moment he accepted," she said.
Her determination paid off, propelling Kom to a string of international boxing titles, national honours and financial rewards to help her family.
Along the way she found time to set up a boxing academy, get married and have twin boys, who are now aged four and looked after by her husband back home in Manipur while she trains.
Despite her obvious drive and talent, Kom said sponsorship deals were a long time coming and the lack of support sometimes upset her.
"I don't know if it's because we don't look like Indians," she said of people from her home state, who live near the Myanmar border and whose facial features are often mistaken for Chinese or Southeast Asian.
Tiny Manipur is home to 2.7 million people and is one of India's "Seven Sisters", an isolated group of states surrounded by five other countries and attached to the rest of India by a thin bridge of land north of Bangladesh.
Insurgent violence has for decades been part of daily life in the region, home to numerous rebel groups whose demands range from autonomy to secession, and whose rival agendas often erupt into bloody clashes.
Kom, who lost her father-in-law to rebel gunmen, has become a hero and a rare ray of hope in Manipur, where she set up her academy to give underprivileged girls and boys the chance to follow her into the ring.
"The youngsters came to me and asked for training and I couldn't say no," she said. "Most of them are very poor."
She now hopes to make her home state even prouder.
To compete at the London Games, where women's boxing is a full Olympic medal event for the first time, Kom must qualify at the world championships in China starting on May 9.
The 157 centimetre (5 feet 2 inches) fighter faces the daunting prospect of taller opponents after switching from the 48kg to the 51kg weight category, the lightest of three groupings to be contested in London.
In preparation, she is sparring only with taller, heavier males.
Her British coach Charles Atkinson, who trained a succession of Thai world champion boxers, believes the set-up could work to her advantage -- as shown by her triumph in the 51kg at the Asian Championships earlier this year.
"A lot of people in that category are reducing weight which can be very, very stressful," Atkinson told AFP. "She should be 50.8 (kg) on fight day without killing herself. It's the perfect scenario for her."
Kom is Atkinson's first female trainee after decades in the boxing business, and it is clear she hasn't failed to impress.
"If anyone beats her they'll have to fight out of their skin," he said. "To me she's a fighter, with a fighting heart greater than some guys I have handled."
As she edges towards her Olympic dream, Kom's drive to be as good as the guys seems to keep her at the top of her game, in a country where "most of the women are looked down on," she said.
"If the men can do it, why can't the women do it? That's my main challenge."