NEW YORK -- Deena Kastor had trouble walking her dog at times. She had to stop to sit on the curb.
The 2004 Olympic marathon bronze medalist didn't run the last five months of her pregnancy because of painful stitches in her side. Doctors told her to wait until her six-week checkup after daughter Piper was born in February, but Kastor got the itch after 2½ weeks.
She planned to jog for a mile -- and then kept going.
"Ended up going on a four-mile run and felt fantastic," Kastor recalled Thursday. "I thought it was just going to be this clumsy stumble, and it ended up being this exhilarating -- sprint is what it felt like."
The American marathon record-holder returns to competition Saturday against an elite field at the NYRR New York Mini 10K. Piper, now 3½ months, took her first plane ride to tag along.
Kastor had planned to run through her entire pregnancy.
"Was pretty floored that I couldn't," she said. "It was really unbelievable to me that I couldn't even just get out to jog for 20 or 30 minutes."
The 38-year-old Kastor had been training with a dogged focus since the age of 11, but she insisted the abrupt break wasn't the least bit trying.
"I've always been a fan of listening to my body," she said, "and was rewarded because of it. For me, it was just a different mission at the time -- it was producing a healthy baby."
Kastor gained only 15 pounds during the pregnancy. She weighed 103 when she found out she was expecting -- and 103 when she came home from the hospital.
"I don't think that's normal and I wouldn't tell someone to focus on doing that," Kastor said. "But I feel very fortunate that weight was not an issue.
"But fitness definitely was," she said.
The first time she trained wearing her GPS watch, she was "rudely awakened" to see she was running 8-minute, 30-second miles. Kastor thought she was going a lot faster.
"I almost took it off and stomped on it at that moment but kept it on as a benchmark of progress week after week," she said. "It's really been extraordinary to be coming at such a low fitness level to see how much progress is made on a weekly basis."
Now she's averaging a 5:35 mile comfortably.
Saturday's race is about gauging her fitness level to plan future training and competitions. The deep field includes reigning 10,000-meter world champion Linet Masai, New York City Marathon winner Edna Kiplagat of Kenya and World Marathon Majors champion Liliya Shobukhova of Russia. The all-women's event will honor nine-time NYC Marathon champion Grete Waitz, who died in April.
"As the New York Road Runners kept releasing the names of athletes running here, my goals kind of shifted: 'I want to get on the podium' to 'OK, maybe top five will be good' to 'Top 10, I'll be really happy with,'" she said.
Kastor is skipping this year's world championships. She'd love to run Joan Benoit Samuelson's Beach to Beacon 10K in Maine in August and plans to do two half-marathons in the fall -- and maybe, depending on how she's feeling, a full marathon.
Everything is building up to the Olympic marathon trials in January.
"As soon as we found out that I was pregnant, I was doing the math: 'Oh, gosh, am I going to be ready for this?'" Kastor said. "I don't have room for error obviously, which is why health is the key."
So she and coach Terrance Mahon are taking things conservatively. She's running about 60 miles a week right now, half of what she'd be doing in preparation for a marathon. Kastor figures she hasn't run that little since high school.
The biggest challenge of motherhood has been the lack of sleep. Kastor used to get 10 hours a night and then nap for two more during the day. The most she's gotten in a day since Piper was born is seven hours.
"She slept like a rock star last night," a proud and relieved Kastor said Thursday of her daughter's first night in New York.
That's appropriate considering the origin of her middle name. Kastor liked how Piper Bloom sounded cheerful, though husband Andrew didn't divulge until after the birth certificate was signed that it was inspired by the Nirvana song "In Bloom."
They actually considered Piper Storm for a while because every time they went to the hospital before she was born, there were whiteout conditions. The Kastors still have 12 feet of snow in their front yard in Mammoth Lakes, Calif.
Doctors weren't sure why Kastor suffered from the side stitches -- dehydration, possibly.
"Piper was not a fan of exercise," Kastor said with a laugh.
By the end of the pregnancy, the 6-pound, 5-ounce baby in her runner's short torso was causing serious lower back pain. Kastor's abdominal muscles are still numb after she had a cesarean section. She's breast-feeding and jokes about the "shift of gravity in my running gait."
Kastor, who won the 2005 Chicago Marathon and 2006 London Marathon, just wants to replace the memory of her last race before her pregnancy. She finished 18th in London in 2010 and is adamant she can still do much, much better.
"When you have these passionate goals in your mind, it's hard to imagine letting them go unaccomplished," Kastor said. "I would love to win the New York Marathon, the Boston Marathon and to get a gold medal in the Olympic Games. That's still a tall order for someone at 38 years old. But I'm going to keep putting myself in the position to chase down goals."