LONDON, England (WRCB) -- Despite a grueling training regimen ahead of his pursuit of another gold-medal haul at this year's Summer Games, Michael Phelps was able to smile.

Allison Schmitt was usually the reason why.

The duo had been training together during the summer for the previous four years, but became full-time training partners last year when Schmitt decided to redshirt her senior season at the University of Georgia in 2011-12 to focus on the Olympics.

Almost immediately, Phelps rediscovered his lighter side.

"When Allison redshirted and moved to Baltimore, having her there was wonderful," Phelps said during a press conference at the U.S. Olympic Trials last month in Omaha. "(It) kind of lightened things up a little bit. And she is a jokester, and that's something cool we have in the pool now.

"There is really no days during the week that she isn't telling a joke or she is not laughing at something that's not funny. She just starts laughing. She is there helping me, and I'm there helping her, and she has been a huge part to lightening things up in the pool at workout, making it more fun."

Schmitt said their opposite personalities work well together, but added their similarities are just as important.

"I feel like we balance each other out," Schmitt said at the U.S. Olympic Team's open practice in Knoxville earlier this month. "I'm a little more spontaneous, all-over-the-place type of person. He's very focused and goal-oriented, but the important thing is that we're both hard-working and have the same goal of brining home hardware for the U.S."

The 22-year-old won silver and bronze in Beijing in 2008, but has her sights set on gold in London after dominating the 200-meter and 400-meter freestyles at the U.S. Olympic Trials.

For that pursuit, she needed a bit of Phelps' no-nonsense work ethic and hyper-focused drive to rub off on her, as well.

"Swimming with him since 2007 has been such a great experience. I feel like I've grown up a lot in the past five years," Schmitt said. "He's always been there for me and shown me the ropes. He's definitely helped me get to where I am today."