NEW YORK - NBC Universal on Tuesday launched Radius, a digital fitness network that will allow people to work out with trainers on their smartphones or tablets.

Radius promises the ability to personalize workout regimens and to tie into a consumer's wearable fitness device. It's also a subscription service of video on demand content that NBC Universal hopes will tap into the lucrative market of workout DVDs, said Nick Lehman, the company's president of entertainment and digital networks.

A sample of its workout programming will air from 6 a.m. to 9 a.m. Eastern on cable's NBC Sports Network.

Consumers will be able to follow video of workouts in many disciplines, including kickboxing, spin or boot camp. Workouts will be available in various intensities, from beginner to regimes followed by some professional athletes.

Radius will give a national platform to five young trainers it hopes to turn into "fitness rock stars"- Basheerah Ahmad, Nicky Holender, Keoni Hudoba, Alex Isaly and Natalie Uhling.

"We think there's just been an explosion of innovation in the fitness area overall and there hasn't been a media brand that can serve as a national platform to capture that innovation," Lehman said.

Subscribers will be able to see the content on Internet-connected televisions, and NBC Universal owner Comcast is making Radius available on TV screens at homes connected to its service, Lehman said.

Radius will also offer information on nutrition, fitness technology and style. It is being offered initially for a $9.99 monthly subscription.

Radius joins other digital sites owned by NBC Universal like Fandango, which markets movie tickets.