She was the oldest woman in the race by seven years, and unlike most of her rivals, has a proper job — and a son. But the 42-year-old American cyclist Kristin Armstrong defended her Olympic time trial title in Rio on Wednesday, powering home four seconds ahead of her nearest rival.

She beat into second place the Russian Olga Zabelinskaya, who won bronze medals in the time trial and road race at London 2012 before failing a drugs test two years later. Anna van der Breggen won a bronze medal, to add to the gold she won in the road race on Sunday.

With three Olympic golds in the same event, Armstrong equals the record set by the Dutch cyclist Leontien van Moorsel, who won gold in the individual time trial in Athens and Sydney, as well as the road race in those Australian games. Armstrong’s five-year-old son, Lucas, watched his mum zoom to victory on a miserable wet and grey day in the suburbs of Rio de Janeiro. On Thursday they will celebrate her 43rd birthday.

The course, and conditions, should have made the women’s time trial the perfect event for masochists – otherwise known as northern Europeans, who grow up riding their bikes in the wind and the rain and learning to stay upright when rumbling over slippery cobbles.

Although most sensible riders find themselves a sunny training base each winter if they can afford it – never a given in the poorly-paid women’s pro peloton – the Dutch duo of Ellen van Dijk and Van der Breggen were unlikely to be fazed by the weather. Nor a Belgian like Lotte Kopecky, who launched an heroic but ultimately doomed breakaway early on in Sunday’s road race.

It wasn’t to be for Van Dijk, the 2013 ITT world champion, who fell off and into the jungle scrub when going uphill. She got straight back on her bike, but lost vital seconds to her rivals.

It drizzled consistently throughout the race, with a nasty wind buffeting the lighter riders on the exposed sections.

Britain’s Emma Pooley is only 5’2” and weighs just 110lb: it looked as though she was being held down by starters as she waited to roll down the ramp behind Alena Amialiusik of Belarus.

Heading towards the first climb she was 30 seconds down on Canada’s Tara Whitten, the 2010 Commonwealth champion, but soon made up time as she danced up the 124m Grumari climb. Though just 1.3km in length, it includes a 17.8per cent gradient section, with an average of 9.4per cent.

Like many of the better-funded riders in Rio, Pooley came to Brazil before the Games to recce the course, riding it over and over for four days in March. “I’m not going to say that I think I’m going to get a medal because that’s totally arrogant, but it is a course that I like as a rider,” she said before Wednesday’s race. It wasn’t to be, when Pooley came in 14th.

She will be glad Zabelinskaya didn’t win. Interviewed before the race, Pooley said she did not agree with the Russian’s inclusion. “That makes me pretty angry because I just don’t trust her,” said Pooley. “I don’t think she should be in the race.”

Asked if she would shake the Russian’s hand in the event of losing to her, Pooley’s answer could not have been a more emphatic. “No,” she said.

Last to start was Team USA’s Armstrong, who set the fastest time at the first check point despite suffering what appeared to be a nose bleed, before dropping back into second as the race progressed, behind Russia’s Zabelinskaya. She won the event in London 2012, when she brought her then two-year-old son onto the podium, and Beijing 2008, when she pushed Pooley into silver.

Due to celebrate her 43rd birthday on Thursday, Armstrong (no relation to Lance) was the oldest of the 25 competitors by eight years. Her selection for this year’s Games was not without controversy, with some suggesting her best form was now behind her. But she won the 2015 USA national championships in the individual time trial and was second in GC at the 2016 Tour of California. An old-school Olympian, Armstrong actually has a proper job working as a community health director in Boise, Idaho, and just rides in her spare time.

Just ahead of her was New Zealand’s Linda Villemsen, whose tattooed arms were covered by a black skinsuit. She won the ITT in the world championships in Richmond last year on an all-black bike after going against her own professional team’s orders not to ride a non-sponsored piece of equipment in the competition.

Born in Denmark, she represented her birth country at the 2008 Olympic Games in Beijing. She became a citizen of New Zealand in 2009 and began competing for her new country in 2010. "The moment I arrived in New Zealand, I knew I wanted to stay. It was in my heart," she said last year. She rolled in fifth.

Women’s time trial results

1. Kristin Armstrong (US) 44 minutes 26.42 seconds 2. Olga Zabelinskaya (Russia) 44:31.97 3. Anna van der Breggen (Netherlands) 44:37.80 4. Ellen van Dijk (Netherlands) 44:48.74 5. Elisa Longo Borghini (Italy) 44:51.94 6. Linda Villumsen (New Zealand) 44:54.71 7. Tara Whitten (Canada) 45:01.16 8. Lisa Brennauer (Germany) 45:22.62 9. Katrin Garfoot (Australia) 45:35.03 10. Evelyn Stevens (US) 46:00.08 11. Alena Amialiusik (Belarus) 46:05.73 12. Ashleigh Moolman Pasio (South Africa) 46:29.11 13. Karol-Ann Canuel (Canada) 46:30.93 14. Emma Pooley (Britain) 46:31.98 15. Eri Yonamine (Japan) 46:43.09 16. Trixi Worrack (Germany) 46:52.77 17. Lotta Lepistoe (Finland) 47:06.52 18. Katarzyna Niewiadoma (Poland) 47:47.96 19. Anna Plichta (Poland) 47:59.66 20. Hanna Solovey (Ukraine) 48:03.35 21. Lotte Kopecky (Belgium) 48:09.86 22. Christine Majerus (Luxembourg) 48:16.17 23. Ann-Sophie Duyck (Belgium) 48:17.60 24. Audrey Cordon (France) 49:32.87 25. Vita Heine (Norway) 50:23.39

(Guardian service)