Then the starting bleep went off and she beat them all.
The 47-year-old Italian made history at a chilly Dorney Lake on Tuesday when she became the first woman to compete in eight Olympic Games. She marked the occasion by qualifying for the final of the flagship 500-metre K-1 event, upstaging a host of younger rivals in her semifinal.
"I don't care about age," she said, laughing. "The stopwatch doesn't ask."
Idem sees herself as kayaking's equivalent of British rowing great Steve Redgrave, who won golds at five straight Olympics — his last coming at the age of 39. She trains for up to seven hours a day and has had a gymnasium built at her home in Ravenna so she can practice and not be away from her two children, Janek and Jonas.
She hasn't quite got Redgrave's titles — she won a gold in the Sydney Games in 2000 as well as two silvers and two bronzes — but her longevity is something no female Olympian has ever matched.
Her first Olympic Games was in Los Angeles in 1984, when she was 19 years old and representing the country of her birth — West Germany. She became an Italian citizen in 1992.
"Someone good can be interpreted as a person that doesn't give up her place for others, or it can be interpreted as a person who pulls along others. I always wanted to be an inspiration," Idem said, still glowing in her remarkable feat.
"I go along to talk to many journalists and do motivational speaking because I really like to give to others what I have learned ... I have worked a lot and fought for many things but I have also been a very lucky person. I have so many things and I want to give back something."
There was a disappointment for another veteran champion, Katrin Wagner-Augustin of Germany, who placed fourth in the same semifinal to miss out on Thursday's final. Wagner-Augustin — Germany's most decorated current Olympian — has won Olympic golds over 500 in the double and four, but never as an individual, and was visibly upset after the race.
She was seen being comforted by her husband, but still has the final of the K-4 1,000 on Wednesday to come.
Emilie Fournel of Lachine, Que., finished sixth in her semifinal and failed to move on to the final.
"I came out really aggressively and unfortunately it was a really long race," said Fournel. "I was battling with the wind. I came here knowing what I had done and I had to line up knowing I could make it.
"But it did not work today."
By winning the first heat, Danuta Kozak of Hungary was the quickest qualifier by nearly a second and had close to two seconds on Idem.
But no one will be discounting the Italian now.
Idem's training regime has been managed with the firm intention of peaking at the London Games. She wasn't even reaching finals of World Cup events a few months ago, but the way she raced through the field after an average start means she is a strong contender to win a medal at a fifth straight games.
"She's an inspiration," said Rachel Cawthorn of Britain, who was overhauled by Idem with 100 metres of the race left. "To keep going for that long and to have been at the top of your game for such a long time, she's so cool."
Idem's children and her husband/coach, Guglielmo Guerrini, were in the family tribune watching her clock a time of 1 minute, 52.232 seconds.
"I'm an Olympic animal ... always for the main event, I am there," she says, slapping the back of her hand. "I did very good work with my training partners this year. Very good work. They were three junior boys from Rome.
"One of them was very fast at the beginning and then I caught him. That was a good experience for today. I was confident, I thought, 'I can make it, I can make it.'"
Off the water, Idem, who has won 38 medals at Olympic, world and European regattas, has campaigned for greater social equality and injustice. With her husband, she has also set up a project that aims to inspire young people to take up sports and promote positive values.
But she has never forgotten about the day job, maintaining motivation even as she approaches the age of 50.
"It is sometimes difficult, because it's so demanding," she said. "You always have to think about it — every day you have to work on it. You go out really tired, you go out with bad weather, you go out having problems at home. But you have to go.
"This is it — it's the effort you have to put in if you want to succeed."
There were heats and semifinals for three other events on a grey day at Dorney Lake.
The Hungarian quartet of Zoltan Kammerer, David Toth, Tamas Kulifai and Daniel Pauman were the fastest qualifiers for the final of the men's 1,000-meter K-4, as the country looks to reclaim the title they won in 2000 and '04 but relinquished to Belarus in Beijing four years ago.
Peter Kretschmer and Kurt Kuschela of Germany confirmed their status as favourites for the men's 1,000-meter C-2 by winning their heat three seconds quicker than Azerbaijan, which surprisingly won the second heat. Kretschmer and Kuschela won both World Cup competitions, in Duisburg and Poznan, this year.
And in the women's K-2 over 500 metres, Franziska Weber and Tina Dietze of Germany beat archrivals Katalin Kovacs and Natasa Douchev-Janics to win their semifinal. Kovacs and Douchev-Janics have won the event at the last two Olympic Games.