Broadcaster promises fitness on smartphones

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 for video on demand content that NBC Universal hopes will tap into the lucrative market of workout DVDs, says Nick Lehman, the company's president of entertainment and digital networks.

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.