U.S. cyclist Kristin Armstrong's 3rd consecutive gold a real tearjerker

Cyclist Armstrong wins third gold medal in time trial (1:03)

Kristin Armstrong talks about competing at a world-class level at the age of 42 after winning the women's cycling individual time trial at the Rio Olympics. (1:03)

RIO DE JANEIRO -- After winning her third consecutive gold medal in the women's time trial, Kristin Armstrong grabbed her 5-year-old son Lucas near the finish line and gave him a tight, loving hug while tears flowed from her eyes. "Mama, why are you crying?'' Lucas asked her. "You won!''

"That's a great question from a 5-year-old,'' Armstrong said. "Why am I crying? Because it's what we do when we're happy! I'm going to have to explain that one to him a little later.''

Well, at least that will be less involved a responsibility than when Armstrong won gold at the 2012 Olympics in London and spent part of the postrace changing Lucas' diaper.

Armstrong, who turns 43 Thursday, is the oldest rider to win an Olympic time trial, surpassing the record she set four years ago. She is just someone who cannot stay away from the sport. Armstrong temporarily retired from cycling after winning gold in Beijing in 2008 so that she and her husband could start a family. After giving birth to Lucas, she returned to the sport and won gold in London. Then she retired again, only to return again in the spring of 2015.

She says she used to think "How can people come back to ride when they are a mother? That's so selfish!'' That is not her view now.

"I can't imagine not bringing this experience to my son,'' Armstrong said. "What I need to do now is make sure that my son doesn't have the pressure on him. It doesn't matter what he grows up to be. And right now he just wants to be a Stars Wars Jedi.

"I have to teach him that participation is good. That it doesn't matter what you become. And the last thing I want him to ever think is that he has to match what I've done.''

Forget about Lucas trying to match it. No one else had ever done it before Armstrong.

Armstrong won the 2008 time trial by 24 seconds and the 2012 race by 15 seconds and Thursday's race by just under six seconds. Given the declining winning margin and her rising age - she will be 46 when the Tokyo Olympics are held - this is probably the end of her Olympic career. Or maybe she'll be like Michael Phelps and keep coming back. She says that while age means that recovery can take much longer, her extra years of experience, her mental approach and technical equipment provide an advantage.

The U.S. women cycled well in the road race Sunday, only to see Mara Abbott get passed less than 200 meters from the end and finish fourth. Despite that terrible disappointment, Abbott provided constant encouragement to Armstrong leading into Wednesday's time trial. She left her a note reading "You are a champion!'' in her coffee cup Tuesday, another in her hairbrush later in the day, a third on her pillow at night and a fourth in her bag Wednesday morning.

"The support that Mara's turned around since her race Sunday has been phenomenal,'' Armstrong said. "That's what a team is all about. I feel we're all genuinely happy for one another. It's given me great pleasure to represent the team. I haven't experienced this in all my years. I feel this was the tightest team I've been on.''

Armstrong woke up early Wednesday to pouring rain, but she wasn't going to let that get to her during the race that began at 9:30 a.m. in Rio. The rain had let up by the race start, but the highly technical course filled with turns and steep climbs still was wet. Wind also was an issue. Armstrong, who was the last biker to start, said she felt a headwind in her face on every turn she made.

Nonetheless, she rode strong and fast enough to surpass Russian cyclist Olga Zabelinskaya and cross the finish line in first place for the gold in a time of 44 minutes, 26.42 seconds.

Zabelinskaya had been banned from cycling for two years for doping, but she was allowed to compete in these Olympics because she had already served out her ban. Armstrong -- who is no relation to Lance Armstrong -- said she didn't think about it too much.

"If the decision is for an athlete to compete at the Olympic Games, then that's the decision,'' Armstrong said. "It was my competition and I came on top today and I was really happy for it.''

And apparently Zabelinskaya wasn't too devastated with losing gold to Armstrong, because she gave the American a big hug after the race.

Said Armstrong: "She told me, 'I saw your son over there. That makes me smile because I have three kids of my own.'''