TOKYO - A Japanese man who runs on his arms and legs has broken his own Guinness world record for the 100-metre dash.

Kenichi Ito finished in 16.87 seconds on Thursday, shaving more than half a second off his 2012 run of 17.47 seconds.

The 30-year-old Japanese has been training for a decade. He studies how primates move through books, videos and zoo visits, and even tries to move on all fours in his everyday life.

Ito hopes racing on four limbs will one day become an official track and field event.

Carlos Martinez, an official adjudicator for Guinness World Records, was on hand to witness the attempt and announced afterward that Ito had set a record.