Eight Japanese Olympic swimmers will go ahead with altitude training for London 2012 as planned after they requested federation permission, despite the death of Norwegian world champion Alexander Dale Oen at a camp in Flagstaff, Arizona, last week.

Cardiac arrest was cited as the initial cause of Dale Oen's death but it may be several weeks before post-autopsy tests in the US come to an official conclusion, investigators said last week. 

Japan's swim federation said it would rethink its altitude training plans but the Japan Swimming Federation told Reuters today that in response to a request from eight swimmers to allow them to train at altitude in France and the United States as planned in the build-up to London 2012, permission had been given.

"We feel great sorrow at what happened (to Dale Oen)," JSF executive director Masafumi Izumi told the news agency. "But the autopsy results did not immediately link his sudden death to the altitude. After holding an executive meeting we decided to take all necessary precautions and prepare the athletes in the safest way possible. We will send doctors to monitor the swimmers and before going we will conduct electrocardiogram and heart echo tests under low-oxygen conditions."

"The swimmers all requested the training go ahead as planned," said Izumi. "We are not forcing anyone. The swimmers want to go and we agreed to their wishes."

Quadruple Olympic champion Kosuke Kitajima is among those who has trained at altitude on several occasions before major campaigns, He aiming to make history by becoming the first man to either retain an Olympic crown for a third time (that would take victory in the 100m breaststroke and no swim or no victory for Michael Phelps in the 400m medley) or the first swimmer of either gender ever to retain a breaststroke crown for the second time.