World 100 metre breaststroke world champion Dale Oen died after suffering a heart attack at a high altitude training camp in Arizona, prompting Japanese officials to rethink their plans.
However, the Japan Swimming Federation said that plans for eight swimmers to train at altitude in France and the United States would go ahead as planned.
"We feel great sorrow at what happened (to Dale Oen)," JSF executive director Masafumi Izumi said.
"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," he added.
"We will send doctors to monitor the swimmers and before going we will conduct electrocardiogram and heart echo tests under low-oxygen conditions."
The eight Japanese swimmers scheduled for high altitude sessions in June and July asked for them not to be scrapped, Izumi insisted.
"The swimmers all requested the training go ahead as planned," he said.
"We are not forcing anyone. The swimmers want to go and we agreed to their wishes."
JSF official Koji Ueno had initially said Japan "could not send any athletes who have concerns under any circumstances".
Multiple Olympic champion Kosuke Kitajima, whose punishing altitude training sessions are well documented, will spearhead Japan's quest in London.
Asia's most successful swimmer is bidding to win the men's 100 and 200 breaststroke double for the third time after taking gold in both races in Athens in 2004 and Beijing four years ago.