When your body wants to take a nap on the job, why not succumb to it? More and more people are beginning to recognize that napping isn't just for toddlers.

Inc.com columnist Jessica Stillman has already protested, "Let your employees nap already!" Simply put, where health, productivity, and revenue are concerned, Generations X through Z stand to benefit.

Currently, nearly half of Americans say that insufficient sleep affects their daily activities, according to research from the National Sleep Foundation. The implications extend beyond health. Lack of sleep costs U.S. companies a staggering $63 billion in lost productivity, according to a September 2011 study from the Journal of Sleep.

The best way to maintain your health and work ethic is, of course, to get the right amount of sleep each night. Experts recommend seven to nine hours. One alternative is to take a nap during the day (20 to 30 minutes should suffice). Another one of our columnists, Erik Sherman, recently tried it--and he's a big fan. 

The benefits are clear: Napping helps you to regain concentration, and it also boosts your productivity. It can reduce anxiety and depression by minimizing your levels of cortisol, which is a hormone that elevates your blood sugar. 

"More and more, we are recognizing the importance of sleep as a mechanism of consolidating information, dealing with the events of the day, and recharging our energy," says Mary Gresham, a clinical psychologist practicing in Atlanta. 

As we already know, many companies actually endorse napping in the workplace, including The Huffington Post. Arianna Huffington's namesake media site has two rooms designated for napping in its New York City offices.

"Increasingly, companies are realizing that their employees' health is one of the most important predictors of the company's health, as well," writes Huffington in her most recent book Thrive: The Third Metric to Redefining Success and Creating a Life of Well-Being, Wisdom, and Wonder.

And Huffington should know. After collapsing from exhaustion at her desk one night (and breaking her cheekbone on the way down), she began pushing to make health and wellness in the workplace a top priority. 

Some companies are even capitalizing on the trend. MetroNaps, for instance, manufactures napping chairs ("EnergyPods") that are designed specifically for office use. Since its founding in 2003, MetroNaps has sold nap pods to high-profile companies such as Google, Zappos, Cisco, and Procter & Gamble. Pods come with features such as a "privacy visor" and a built-in speaker system. Startups, take note: Each chair retails for $13,000.

Today, roughly 6 percent of employers have nap rooms onsite, a 1 percent increase from 2008. From scrappy startups to tech behemoths, here are a few companies that will encourage you to rest and recharge:

Uber

The ride sharing company's San Francisco headquarters includes nap rooms. These were designed by interior design firm Studio O + A, under the supervision of principal Denise Cherry. 

"For Uber, a company known for regulatory battles, we were tasked with creating a room built for maximum efficiency--a room so built for work that no one would need to leave," says Cherry. "This included a living room space, a kitchenette, and, of course, small focus rooms that double as nap rooms."

Google

The perks at Google's Mountain View, California, headquarters are aplenty: nap pods, complimentary food and drinks (including a coffee bar with a full-time barista), and shower rooms, to name a few. 

Zappos

Tony Hsieh, famed implementer of the Holacracy (self-government) workplace regime, is also a proponent of napping at work.

Perks at the online shoe retailer's Las Vegas headquarters include EnergyPod chairs, massage chairs, regular wellness fairs, and onsite health screenings. 

Capital One Labs

World's Coolest Offices 2014 honoree, the software company Capital One Labs has a wildly bright interior, meant to nurture the creative spirit among its San Francisco team. 

It also houses sleeping nooks, which are connected to the ground by way of ladders and "gabled blue" support beams.

Ben & Jerry's

One of the earliest adopters of the workplace napping policy, the Burlington, Vermont-based ice cream company has had an office nap room for more than a decade.

"The room itself is really part of the larger corporate culture here and the company's belief that a happy employee is a productive employee," a spokesperson told the BBC.

PwC

PricewaterhouseCoopers is another surprising adopter of nap pods. 

"A lot of companies are realizing that good performance needs a balance of healthy eating, resting, and focusing," says Stefan Camenzind, CEO of Evolution Design. The Swiss design firm recently wrapped up PwC's 50,000-square-foot offices in Basel. Evolution Design has also worked on projects for Google in Tel Aviv and Dublin.

"Most people are told that the harder you work, the longer you work, the better it is," Camenzind adds. "That's not sustainable, and that's probably also not true. It's about smart working, and that means you need to recharge. In this context, nap rooms become more and more important."