Fold, stuff, glue. Fold, stuff, glue. In the front room of Rep. John Yarmuth’s Congressional office, the Kentucky Democrat’s staff assistant Marisa Wittebort folds letters to constituents into thirds, stuffs them into envelopes and sticks them shut.

The clock reads 6:15 p.m. ‘ time to wrap up the 10-hour workday.

The 25-year-old assembles the last letter. Fold, stuff, glue. She turns the phones to voicemail for the evening, tidies her desk, grabs her yoga gear and a blueberry granola bar and clicks off the lights as she shuffles out the door.

From the Cannon House Office Building down Pennsylvania Avenue, Wittebort heads to a hole-in-the-wall yoga studio near Eastern Market. The brisk walk warms up her leg muscles for the upcoming hour of intense stretching and balancing while her mind drifts, reflecting on the day’s challenges.

It’s a typical day for Wittebort, a routine she follows at least four days a week. A half-hour after leaving her office, she’s in an underground yoga studio sitting in ‘sukhasana,’ a pretzel-like meditation pose with palms facing up on her thighs.

With its deep-lunge stretches, contortion-like balances and breathing-focused exercises, yoga seems to draw stress-prone Hill employees to studios across town.

It’s no wonder ‘ the physical and mental discipline, which originated in India under Hinduism and Buddhism, has a unique effect on the body and mind, serving both as an exercise class and a time to reflect and meditate.

At the House Staff Fitness Center, the gym’s yoga classes are the ‘most popular group class by far,’ center associate Eileen Danielski said. Twenty to 30 House staffers attend each of the week’s four classes, she said.

The Supreme Court, Federal Trade Commission and Food and Drug Administration offices are also rumored to offer yoga classes for employees weekly, and yoga instructors on Capitol Hill have noted a large number of staffers practicing.

Wittebort caught the yoga fever after she moved to D.C. during the spring of 2009. Hoping for a position in politics, she found herself barely making ends meet as a waitress.

Noting her stress level, an acquaintance recommended yoga as an escape for Wittebort, and she got ‘sucked in,’ she said. Now she dons her yoga gear almost daily, and when the phone calls and constituent letters pile high on her desk, she’s able to relax and rejuvenate with evening yoga classes at Capitol Hill Yoga.

‘Life throws things at you: Sometimes it’s your job, sometimes it’s a friend or family member who’s hurt you,’ Wittebort said. ‘Yoga really helps you put things into perspective. I feel like I’m rebooting my system each time I go.’

Laura Castagnino, center manager and head yoga instructor at Dahn Yoga, said several lawyers who take her lunch-hour yoga class have also come to rely on it: ‘They always say that on the days they don’t come to class, they have to stay at work late because they can’t focus to get their work finished on time.’

Yoga has many relaxing and meditative components. At Capitol Hill Yoga, instructors often begin class with an intention of the day, such as ‘never shy away from difficult times,’ or ‘be comfortable with uncertainty.’ Instructors try to give students a way to reflect in a healthy way on troubled areas of their lives while celebrating their accomplishments.

‘As a former Hill staffer myself, I know well the high stress and long hours asked of staffers … it’s why I went to my first yoga class in 1999,’ said Betsy Poos, co-owner and studio manager of Capitol Hill Yoga.

Spending more than a decade in the political sphere, Poos worked for former Rep. and current Sen. Debbie Stabenow (D-Mich.), the Democratic Congressional Campaign Committee and a lobbying firm before quitting her job to become a full-time yoga instructor.

She first started taking yoga to ‘remove myself from the day-to-day stresses,’ she said, but classes became less of a getaway and more of a lifestyle. A few years later, she started teaching yoga after work, running from the Hill to gyms and yoga studios throughout the week.

‘People actually noticed a shift in my personality after I started taking yoga,’ she said. ‘I had always been a fast, competitive sort of person ‘ as any Hill staffer would be ‘ but the meditation was chilling me out.’

Poos thinks the physical aspect is what attracts newcomers to yoga. But yoga is also therapeutic.

Simone Litrenta, director of scheduling for House Majority Leader Steny Hoyer (D-Md.), started taking yoga a year ago after being diagnosed with rheumatoid arthritis. The disease caused the young woman pain in her elbows, knees and ankles.

‘I found that when I started going to yoga the pain subsided, and between yoga and my medication, I haven’t had much aching for over a year,’ she said.

But as with most daily yoga practitioners, yoga became more than a physical exercise for her.

‘When you work on the Hill, your mind is always going, and your days are not short by any means,’ she said. ‘We can work from 8:30 a.m. to 6, 7 or 9 p.m. Work is constant, and there is always something going on in life. Yoga is the time where everything gets blocked out. No newspapers, no BlackBerrys, no TV, no cell phones ‘ there are none of those distractions.’