TOKYO -- Commuters in Tokyo are honing their straphanging skills as East Japan Railway and JR East Sports roll out a novel smartphone app that lets passengers exercise while riding the train.

Dubbed 'Train'ing, the app suggests workout routines to passengers depending on where they are located on a train and how crowded it is.

The app is being tested on Tokyo's busy and frequently packed Yamanote Line, and can be used until March 12.

Passengers looking for a light workout between stops open the app while waiting on the platform, selecting the stations where they will be getting on and off. They can even choose the type of workout. By entering the seat location and strap number after boarding, the app also suggests exercises suitable for the area.

JR East may introduce the app on other lines if all goes well, a company spokesperson said.

The Yamanote Line circles central Tokyo, with the entire run taking about an hour. It stops at many of the city's largest stations and connects with numerous other train and subway systems.

An average of 1.13 million passengers used the Yamanote Line daily between Tamachi and Shinjuku stations, which includes stops at busy Shinagawa and Shibuya stations. During peak morning hours, the trains are so crowded that conductors literally stuff passengers into the cars.

Next spring, JR East will open its first new station on the line in roughly 50 years. Named Takanawa Gateway Station, it will become the 30th stop on the line.