Natalie Coughlin has thought about quitting, about getting on with the rest of her life.
Usually, those thoughts wash over her after the Olympics, when she's pushed herself to the brink in training and can't bring herself to swim even one more stroke.
Inevitably, after taking a few months to reflect, her love for the sport returns.
Then she'll realize: Why give up something she enjoys so much?
''I love working out. I love the process,'' Coughlin said during a recent meet in Charlotte, North Carolina. ''I would be doing this anyway. I would just have to balance a real job on top of it if I retired. Why do that when I can just do this full time?''
At 32, Coughlin knows she's in the twilight of a brilliant swimming career. But she's making a run at her fourth Olympics and the chance to become the most decorated female athlete in U.S. history.
Her commitment is impressive to an almost entirely younger group of competitors.
''I know how hard it is for me at 28,'' said Jessica Hardy, who won two medals in London. ''It can't be easy for her.''
With a dozen medals in her trophy case, there's really nothing left for Coughlin to prove.
But one more trip to the podium in Rio would put her at the top of the list all by herself, breaking a tie with Dara Torres and Jenny Thompson. Torres was the oldest female swimmer to compete at an Olympics when she swam in Beijing at age 41, and brought home three silver medals.
''As you get older, it really gives you perspective on how special this is, how finite this is,'' Coughlin said. ''It's way more enjoyable now. I've already won 12 medals. I don't need any more medals to validate myself. It's fun. I'm really enjoying this. There's really no pressure other than what I put on myself.''
Coughlin was once America's most dominant and versatile female swimmer, often mentioned in the same breath with Michael Phelps. She ranked among the world's best in three strokes - backstroke, freestyle and butterfly. She won five medals at the 2004 Athens Olympics, six more at the Beijing Games four years later.
Not that it was an entirely enjoyable ride.
''My younger self, I was angry. I was so competitive,'' Coughlin conceded. ''I'm still crazy competitive, but I know where swimming fits in my life. It's not my life. It's what I do.''
Her career appeared to be winding down at London, the torch passing to a new generation of female stars led by Missy Franklin. Coughlin failed to qualify for an individual event, making the U.S. team solely as a member of the 4x100-meter freestyle relay. Even then, she competed only in the morning heat, receiving a bronze medal when the Americans finished third in the evening final.
Instead of fading into retirement, as many expected, Coughlin was determined to keep going.
''It wasn't really a question of whether to continue to swim or not,'' she recalled. ''I just knew I needed a change, so I made those changes.''
Most notably, Coughlin went with a new coach.
For 12 years, she had worked with Cal women's coach Teri McKeever, a highly productive partnership that carried over to a close relationship away from the pool. With her career at a turning point, Coughlin switched to the men's coach at the Berkeley, Dave Durden, giving her a chance to work with top male sprinters Nathan Adrian and Anthony Ervin.
For Coughlin, the men's group provided the sort of training she needed moving into her 30s. It's not uncommon to switch coaches or training plans as a swimmer ages - some switch to shorter events that create less wear or tear, switch up coaches or alter training plans.
''It was tough'' to leave McKeever, Coughlin said. ''But both of us were on the same page that I needed to do something different. More than anything, I was so much older than rest of the girls on Teri's team. My needs were so different. My needs were much more similar to Nathan's and Anthony's. It would have been selfish of me to ask and demand that from Teri's group.''
There were other benefits, as well.
''When you work with the same person for so long, they see you every single day. That can get stale,'' Coughlin said. ''It's like someone going through a weight loss. If you lose 50 pounds over three months, you might not notice it if you see that person every day. ... I just needed a new set of eyes and kind of a refresh.''
Durden has been most impressed with Coughlin's drive to improve, even if it's something as simple as a kick set the team does on Friday mornings.
''She's the consummate professional in terms of getting to practice, her routine, how she moves through it, the thoughtfulness she places on what she's doing,'' he said. ''That's pretty darn impressive.''
With Durden's group, there's more of a focus on weight training to build up speed for the freestyle sprints. Coughlin has also worked on altering her stroke, looking to get less rotation, remain flatter against the water and expend less energy. Looking to get more flexibility in her shoulders, Durden has pushed Coughlin to resume competing in the 100 backstroke, an event she won in both Athens and Beijing.
''Chipping away, chipping away, chipping away,'' Coughlin said with a smile. ''Hopefully at the end, you have a sculpture.''
And maybe one more Olympic medal.
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