The London Olympics are over and, for me, one of the lasting images will be that of cyclist Kristin Armstrong, who turned 39 on Aug. 11, holding her young son in her left arm and her gold medal in her right hand.

I think it resonates with me because four years ago in Beijing when she also held a gold medal in her right hand but nothing in her left, she was like so many of the rest of us. She thought of family and achieving her fitness potential as an either-or proposition.

I talked to Armstrong a few months before the Olympics and she explained that she waited to have her son, Lucas, until after the Beijing Games so she could retire from cycling to focus on him.

“I was done with sports,” she said by phone from her Boise home. “I said I would never be one of those people who did this with a child. I guess I was a hypocrite.”

Actually, Armstrong, who worked as a YMCA swimming instructor, discovered what so many of us recreational athletes have a hard time learning. It is possible to be a good parent without compromising our fitness. Even if you’re a world-class athlete.

Lucas was born Sept. 10, 2010, less than two years before the London Games, but Armstrong couldn’t help but think about a possible comeback.

“I didn’t know if I could do it or if my body would ever be normal again after having a baby inside me,” Armstrong said. “But I thought, cool, I need a goal.”

So shortly after Lucas’ birth, Armstrong got back to work. She couldn’t sit on a bike seat for several months so Armstrong trained in the gym, hiked, swam, did yoga and other activities to get in shape.

“I learned my mind was stronger than my body,” Armstrong said. “My mind would say, ‘Do this.’ But my body would say, ‘Wow! Not yet.’ ”

Training for the Games while raising a son wasn’t easy, she said. Lucas wasn’t the least bit shy about waking his mom during the wee hours of the morning even if she had an important training ride. And she always carved out breaks in training to feed and play with her son.

“It’s a different type of challenge (than preparing for the ’08 Olympics),” Armstrong said. “It’s a wonderful balance and I really enjoy it.”

When she’s not on her bike, Armstrong says she spends almost every moment with her son. “And thank goodness my husband (Joe Savola) is such a great dad,” she said. “He’s so amazing with Lucas.”

While parenthood sometimes seemed more challenging than training, Armstrong slowly reclaimed her pedal power. In April, she won the time trial and finished second overall at Belgium’s Tour of Flanders for Women. By May, she declared herself “just as strong as I was going into Beijing in 2008.”

Then she fell in a hometown race and broke her collarbone and the whole comeback was briefly in doubt.

With two gold medals and two world championships on her resume, Armstrong said she’s retiring now and will spend even more time with her family. But it’s clear that she’ll continue to find joy in balancing fitness and family.

“You don’t have to pick one or the other,” she said. “But being a mother always comes first.”