Peak performance

“I noticed that in the pool, my legs felt very heavy,” she said. “I was dragging my legs more than I used to and it hurt my swimming.”

Other times, she would swim fluidly but feel lifeless when she ran or cycled.

After five years as a multisport athlete, Ms. Higgins, now a 32-year-old postdoctoral research fellow at Princeton University, said the push-me-pull-you feeling has not gone away.

It made Ms. Higgins wonder something that may be on the minds of the nation’s more than 100,000 triathletes, too: Is it even possible to peak in more than one sport at once?

Anne Gordon, 51-year-old triathlete and a partner at Dubilier & Company, a private investment group, has never gotten a personal record in each leg of a triathlon on the same day. “I find it is possible to peak in two out of the three sports, but no matter how hard I try the third eludes me,” she said.

Neither, though, is about to give up triathlons. They love the training, the discipline and competitions that allow a little leeway. For instance, if you are a weak cyclist, you may still do well with a fast run and an adequate swim. Multisport athletes can play on their strengths.

“The simple act of working hard at three things requires a diversity and balance in my life that is rewarding in and of itself,” Ms. Gordon said. “It is good for my spirit to know that I have to work hard and be patient to achieve mastery.”