Fox Sports has joined ESPN on the team of sports channels hoping to boost ratings by adding viewers at bars, restaurants, gyms, hotels, and (yes) at work: Nielsen says today that Fox’s FS1, FS2 and Fox Deportes have signed a multiyear agreement to use Nielsen’s new National Out-of-Home Reporting Service.

Nielsen introduced it in April, with ESPN as the first client.

Fox will receive program and commercial ratings for live viewing, and viewing up to seven days after a live broadcast. The weekly reports will include daily numbers blending out of home data from Nielsen’s Portable People Meter with national TV ratings.

The Portable People Meter can detect whether users are away from home, and report when they are watching or listening to TV. It’s an opt-in service with nearly 77,000 panelists. It’s in 44 local TV markets and can account for 65% of the U.S. household population.

“Sports are being watched everywhere, every day and on every type of screen,” Fox Sports COO Eric Shanks says. “Our business has to keep pace with changes in viewer behavior.”

Sports services have long complained that they were short-changed by Nielsen’s home based ratings.

Nielsen says that Fox’s ratings for 18-to-49-year-old NFL viewers in the regular season would have been 16% higher with the out-of-home measures. The additional also would have shown the audience to be younger, more diverse, more female, and more affluent.

“We are committed to providing our clients with a complete view of their total audience regardless of where consumers are viewing their content,” Nielsen U.S. Media President Lynda Clarizio says. “Our out-of-home measurement service is another piece of Nielsen Total Audience delivering to subscribing clients richer and more robust insights into their viewers, as well as helping to uncover new and valuable audience segments.”