Harvard professors are known worldwide for their minds, but after classes end, these bookworms can often be found not in libraries but instead in spandex, struggling to make their physiques live up to their intellects.

Dean for the Humanities Maria Tatar was busy riding her bike on Memorial Drive this past weekend when she phoned in to discuss her fitness routine.

“No matter how intellectual and high level a conversation among faculty may be,” she said while pedaling, “I’ve noticed that the last five minutes always turns to what people are doing to keep in shape.”

Squeezing fitness into a schedule packed with classes, meetings and book tours would make anyone sweat, but minds from the sciences and humanities alike somehow find time for more.

“My impression is that most of the faculty tries hard to keep in shape,” Dean of the College Benedict H. Gross ’71, wrote in an e-mail.

For Gross, this means a couple of games a tennis a week and a swim on the days he can’t hit.

His tennis partners include house masters Howard Georgi and Sean Palfrey in addition to President Lawrence H. Summers, the big man on campus.

But Summers holds down the baseline for more than just love of the game.

Last year, in a Crimson article, he attributed much of his weight loss to a “low carb, high tennis” diet.

In most cases, however, shedding pounds does not weigh as heavily.

Dean for the Social Sciences David Cutler, an expert in public health, is an avid runner and logs between 25 to 30 miles in a week. He has run three marathons in his lifetime, including last year’s Boston marathon. In addition to the obvious health benefits, Cutler says that running along the Charles is an opportunity to relax even if it means getting up at 6:30 a.m.

“What suffers in the end is sleep,” he said.

Some professors work exercise into their daily lives.

Tatar says that she uses her bicycle as the main means of transportation, and Frankfurter Professor of Law Alan M. Dershowitz said that he purposely parks far away from his destination in order to fit in more walking.

“I’m about to leave for the Red Sox game,” he said yesterday afternoon, “but I’m going to walk all the way there.”

When Dershowitz is looking for a more intense workout, he hits the gym.

“The problem is that when I try to work out in a public gym, I get interrupted by a lot of people telling me what they think of me,” he said.

He used to play pick-up basketball with students, but he has cut back as his skills declined.

“I like to be good at everything I do,” he said.

To circumvent the problem of public workouts, he has set up a gym in his home that includes a treadmill, an elliptical trainer and a universal weight station. He rotates through the machines with his wife and daughter while the three watch a movie.

When a movie is not playing, Dershowitz uses his workout as a time for reflection.

“Sometimes it can be a way to think about my classes and my writing,” he said. “I use exercise to think through some puzzles.”

While Dershowitz uses his workouts for planning, his law colleague, Charles Fried, looks forward to unwinding and listening to music while running on the treadmill.

Fried uses the equipment at the Malkin Athletic Center (MAC), especially now that it has been renovated.

“What they’ve done is terrific,” he said. “It was a long time coming. For a while every third-rate Holiday Inn had facilities better than Harvard.”

While Fried is satisfied with the MAC’s makeover, many other faculty members use private health clubs.

Tatar said that she is a member of the Mt. Auburn Club, where she is currently taking a class in gyrotonics—a combination of ballet and yoga.

“It’s great to try something new every year,” she said.

Tatar, a veteran exerciser, aims to work out every day. “I try not to be too fanatical about it, but I would put myself close to that category of fitness junkie.”

Tatar says she’s spotted several of her peers at the gym, including Radcliffe Institute Dean Drew Faust and University Professor Barry C. Mazur.

Professor of Psychology Steven Pinker prefers not to be confined to a gym. An avid outdoorsman, he wrote in an e-mail, “I like any kind of exercise that causes scenery to go by at a rate that depends on how hard I work out.” Those activities include biking, jogging, sculling, roller blading, kayaking and hiking.

When Cambridge winters get really bad, Pinker sets up a rowing ergometer inside or turns the pedals of a stationary bike.

Tatar also mentioned fierce winters as the only damper on her physical activity.

So when snow and ice settle in on Cambridge, how do professors find the motivation to break a sweat?

Tatar suggested that encouragement may come from the classroom.

“We are around young people all the time,” she said. “We look extraordinarily old to these people and that puts pressure on us.”

—Staff writer Wendy D. Widman can be reached at widman@fas.harvard.edu.