The report, leaked to the Independent Group, was compiled by the South African squad's fitness specialist Andrew Gray and submitted to the United Cricket Board (UCB).
The newspapers reported that Gray found leading players Herschelle Gibbs, Allan Donald, Jacques Kallis and Lance Klusener particularly errant in their preparations for the World Cup.
South Africa had a dismal World Cup despite playing at home and being regarded among the favourites and were eliminated in the first round of the tournament held in February and March.
Simons, who is currently in Bangladesh with the South African team, issued a statement on Thursday through the UCB in which he attacked the leaking of the document and said much of the report had been taken out of context.
"It was with anger and frustration that I learnt about the article," Simons said in the statement. "Clearly it was written by a journalist with no understanding or knowledge of the team or our World Cup campaign."
"Highly confidential reports have been leaked by a person or people, who have little or no sense of moral integrity, to a reporter who has acknowledged to the UCB that he knows very little about the game."
Simons was also critical of the way in which the article was written and of the South African media in general.
"As coach I have seen both the report and the article and it is clear that the writer has chosen to exaggerate and twist the content purely for the sake of sensationalism as the article makes no attempt to present the facts fairly.
"Obviously, as a squad we are desperately disappointed at our performance and the outcome of our World Cup campaign. But the issues raised so sensationally in the article were dealt with months before the tournament and were not, in any way, a factor at any stage of the tournament," Simons said.
"I have found the endless, destructive attacks by certain sections of the South African media disappointing in the extreme, particularly when the positive angles are so often ignored."
Simons said the publication of the fitness report had had a demoralising effect on the squad currently playing the first of two Tests against Bangladesh in Chittagong.
"The story reached us just before our team meeting on Wednesday night and I can honestly say I have never experienced a more subdued and dejected meeting as the one that followed. And this, just twelve hours before a Test match."
"The captain (22-year-old Graeme Smith) did his best to pick the team up in the meeting, and in the end they understood the need to look forward and focus on the Test match and an exciting future," Simons said.
