CEOs at Fortune 500 companies have been slow to embrace social media, but their participation on two social media platforms in particular, Twitter and LinkedIn, is growing.

A study sponsored by Domo and CEO.com found that 5.6 percent of Fortune 500 CEOs are now on Twitter, compared to just 3.6 percent last year. Overall, roughly 18 percent of the adult U.S. population is currently on Twitter, according to research from Pew Internet.

The Domo/CEO.com study also found that 27.9 percent of CEOs are active on LinkedIn, compared to 25.9 percent in 2012.

LinkedIn remains the one social media platform that is actually more popular with CEOs than the general public. Pew Internet reported that 20 percent of the adult U.S. population is on LinkedIn

The report also found that the number of Fortune 500 CEOs on Facebook remains virtually unchanged from a year ago. In 2012, 7.6 percent used Facebook, compared to just 7 percent this year. The presence of Fortune 500 CEOs on Google Plus is also stagnant, with just 1 percent active on the network this year, compared to 0.8 percent last year.

“The rise of Twitter in particular really points to the need for speed among CEOs,” said Josh James, founder of CEO.com and Domo, a new cloud-based business intelligence software company.

The study found there are currently 28 Fortune 500 CEOs on Twitter with a combined total of 2,126,564 followers. However, the researchers found, up to 30 percent of CEOs’ Twitter followers include fake profiles.

According to the study, there are 140 Fortune 500 CEOs on LinkedIn, 25 of whom have more than 500 connections.

The most popular CEO on Facebook is its very own founder, Mark Zuckerberg, with 16,742,363 followers.