Naoki Matsuda collapses during training

Updated: August 2, 2011, 10:10 AM ET
Associated Press

TOKYO -- Club officials say former Japan national team defender Naoki Matsuda collapsed during training after suffering a cardiopulmonary arrest.

The 34-year-old Matsuda was unconscious when he arrived at a hospital Tuesday and has been on an artificial cardiopulmonary unit, Matsumoto Yamaga Football Club team officials say.

His condition was "extremely severe," club president Hiroshi Otsuki said.

Matsuda collapsed after finishing a 15-minute warmup run during training, coach Yoshiyuki Kato said.

Matsuda played 40 times for Japan, including at the 2002 World Cup, which was held in Japan and South Korea.

Record high temperatures across Japan have caused a rise in heatstroke cases. A total of 43 people have died from heatstroke in the past two months, Kyodo reported.

Copyright 2011 by The Associated Press