The parking lot at Fair Isaac Corp. in San Rafael, Calif., is empty when Michelle Davis pulls in at 6 a.m.

For the next 8-1/2 hours, the 36-year-old analytics director will shuttle through nearly back-to-back meetings at FICO, a company best known for calculating consumer credit scores. At 2:30 p.m., the mother of three will leave work to pick up her children from summer camp. Technically, she's off the clock, but she'll keep an eye on her BlackBerry long into the night.

Welcome to middle management circa 2013. Fourteen years into her career at FICO, Ms. Davis is sandwiched somewhere between seniorleadership and the front lines, overseeing three direct reports along with three other subordinates. Her job affords her the freedom to run projects and pitch new ideas, but it's not without constraints.

Like her midlevel peers in retail, technology and other industries, she has many duties but little authority, people to please both above and below, and days when her schedule is just barely under her control, filled with meetings or consumed with sudden crises.

Midlevel managers -- whose ranks numbered 10.8 million in the U.S. last year, according to the Bureau of Labor Statistics -- are often dismissed in popular culture as paper-pushers, perpetuators of groupthink and symbols of organizational bloat. But management experts say they're an essential layer of a company, turning top-line strategy into action, day by unglamorous day. Yet managing without much autonomy is stressful, and opportunities for getting ahead are limited.

What's different now is that companies are leaner than ever, placing greater demands on staff even as they invest in technology that threatens to eliminate many jobs. Companies are asking managers to do more, challenging them to create and innovate while still developing talent and meeting deadlines.

Ms. Davis, who tends toward muted dresses with flats and uses 'road map' as a verb, allows that she's not 'saving the world' overseeing predictive models for credit-card portfolios. She says the work is intellectually satisfying, 'a puzzle that you're trying to solve all the time.'

The early hours of the workday are the most productive for Ms. Davis, when the hallways are dark and the only interruption comes from a staff member in Birmingham, England.

In her office, a beige box with a few decorations and books such as 'Power Speaking: How Ordinary People Can Make Extraordinary Presentations,' she catches up on messages and responds to a client's urgent request for data.

When she can, she uses this quiet time to make progress on new projects, such as a platform that allows staffers to share information used in building common analytics models -- the kind of work that may eventually move her up the ladder. By 7:30 a.m., meetings begin. First is a monthlyconference call with the analytics board of directors, an internal group working to integrate the analytics team with the rest of the company. She nibbles on a bagel and puts her phone on mute so colleagues don't hear her keyboard clicking as she checks email.

Next, she leads an hourlong training session, walking a few dozen staffers through a new analytics product focused on customer management. A former middle-school math teacher, Ms. Davis knows how to command a classroom, mixing self-deprecating jokes with technical instruction.

In a 10:30 a.m. check-in with senior members of the product development and product management teams, Ms. Davis relays worries from her group about an internal analytics product, but no one is explicitly assigned to make the fixes.

Ms. Davis coordinates the analytics that go into credit-card originations and account management, but other groups handle software and the products that banks use.

Working with teams reporting up separate chains of command can be 'frustrating,' Ms. Davis says, but it's a big part of the job.

Organizations want middle managers to wield soft power and spend more time working across departments, according to management experts.

Still, turf wars take a toll, and middle managers are apt to feel the strain. A recent study of Barbary macaques published in the journal General and Comparative Endocrinology showed that animals in the middle levels of a social hierarchy, pulled into power battles, exhibited the highest levels of stress -- a finding that researchers say applies to humans in the workplace.

It's easy for a middle manager to resemble 'a rat on a wheel,' working hard but not actually advancing, says Lynn Isabella, an associate professor of leadership and organizational behavior at University of Virginia's Darden School of Business.

Ms. Davis says that's not the path she's on. 'I've heard of people in the middle who are happy, who want to stay there,' she says. 'That's not me. I always strive for more.'

But she doesn't know what that 'more' is yet, and both she and her boss, FICO's chief analytics officer, Andrew Jennings, say it would be a big leap to the next level. Mr. Jennings has 10 direct reports who oversee a combined 130 staffers. He works for the chief technology officer, who then reports to the chief executive officer.

While Ms. Davis likes developing her employees, balancing people management with her analytics duties hasn't been easy; about a year ago she reassigned some direct reports to another team member. 'It takes time to do management right,' she says.

Ms. Davis lost a former boss, and that boss's boss, in a wave of layoffs in 2011, but she feels secure given her long tenure. However, that commitment isn't necessarily mutual.

'Middle managers really want to feel that their company is loyal to them,' says Jacob Spilman, a Portland, Ore., based counselor who is creating a series of online seminars aimed at helping middle managers cope. 'More and more often, that's a fantasy,' he says.

Lunch for Ms. Davis is a quick noontime stop for Chinese chicken salad at the company cafeteria. Given to frugal habits, she usually brings in leftovers.

She earns a good living, making more than $150,000 a year -- nationally, the median earnings for middle managers just tops $90,000 -- but it doesn't go far in Marin County, Calif.

Together with her husband, a senior engineer at a cloud computing company, they earn nearly $300,000, though mortgage payments for their modest Terra Linda home, bought a couple of years ago for $680,000, eat up a lot of the family paycheck.

Ms. Davis's last meeting of the day -- updating predictions on consumerpayment -- runs long, forcing her to scramble to pick up her children, ages 7, 9 and 10, from camp on time.

She knows she's lucky for the time at home, and uses vacation days to chaperone a few field trips each year. Just 44% of middle managers are satisfied with their work-life balance, compared with the 70% of employees without managerial responsibility, according to a recent U.K. study of workplace attitudes.

But Ms. Davis admits it's tougher for her than for some of the other moms, who work flexible jobs, if at all, and get together for regular workouts -- 'ladies who Lululemon,' she says wryly.

She'd like to get in better shape, but her best shot at exercise right now is climbing the stairs in her three-story office building.

While the kids scarf down snacks and play in the backyard, Ms. Davis checks email and takes some calls. After dinner, she'll try to grab a few minutes alone with her husband, and then it's bed by 10 p.m.