Sony Corp. said Thursday it plans to launch a training headset for runners called Smart B-Trainer that uses music to help runners adjust their pace.

The 43-gram device monitors heart rate, calorie consumption and running pace, and even selects songs for adjusting the pace, from a databank that can store up to 3,900 songs.

The device is expected to sell for around ¥30,000 ($250) when it hits store shelves on March 7.

Sony will provide training plans by shoemaker Asics Corp. and marathon commentator Tetsuhiko Kin for free to customers who buy Smart B-Trainer, allowing them to hear their advice through the headset while they run, the firm said.

Sony believes demand for the device will be strong in Japan, where some 6 million people said they went running at least once a week in 2013, the electronics giant said.