Lance Armstrong was at the heart of the biggest doping conspiracy in sports history when he won the Tour de France seven years in a row, a US Anti-Doping Agency (USADA) report says.

USADA submitted a report to the International Cycling Union (UCI) and World Anti-Doping Agency (WADA) on why it banned Armstrong for life in August and released more than 1,000 pages of evidence from its probe of doping in cycling.

"Lance Armstrong did not merely use performance-enhancing drugs. He supplied them to his teammates," the report said.

"He was not just a part of the doping culture on his team. He enforced and re-enforced it."

Evidence included testimony from 11 of Armstrong's former US Postal cycling teammates, an expert's finding that Armstrong blood changes indicated doping and documents showing a payment to doping-linked doctor Michele Ferrari.

"The evidence of the US Postal Service Pro Cycling Team-run scheme is overwhelming," USADA chief executive Travis T Tygart said on Wednesday.

"The evidence shows beyond any doubt that the US Postal Service Pro Cycling Team ran the most sophisticated, professionalised and successful doping program that sport has ever seen."

Eyewitness testimony of Armstrong taking EPO and testosterone and having blood transfusions came from such former teammates as Tyler Hamilton and Floyd Landis, admitted dope cheats, and George Hincapie, who confessed on Wednesday that he took performance-enhancing drugs.

Other former Armstrong teammates who testified include Frankie Andreu, Michael Barry, Tom Danielson, Levi Leipheimer, Stephen Swart, Christian Vande Velde, Jonathan Vaughters and David Zabriskie.

Tygart said the program was designed to evade detection as well as pressure athletes into taking drugs and maintain a "code of silence" about activities.

"We hope the sport will use this tragedy to prevent it from ever happening again," Tygart said.

USADA also cites e-mails, scientific data and financial records, included more than $US1 million in documented payments from Armstrong to a Swiss company run by Ferrari, who purportedly advised him on doping.

A medical expert said changes in Armstrong's red blood cell count between samples taken at the 2009 and 2010 Tour de France races and during his earlier run of victories would naturally occur in less than one person in a million.

"The evidence in the case is beyond strong," the report said.

"It is as strong as or stronger than that presented in any case brought by USADA."

Armstrong was banned for life by USADA and stripped of his seven Tour de France triumphs from 1999-2005 after declining the chance to challenge the doping charges against him before a USADA arbitration panel.

Armstrong, who has denied any wrongdoing, said he was weary of years of allegations against him and tired of fighting, instead hoping to focus on his Livestrong foundation and anti-cancer fundraising activities.

"We weren't about to go through another year like the last two years dealing with the emotional and financial stress on Lance," Armstrong attorney Tim Herman said.

The decision not to press ahead with a defence against the charges and confront the witnesses and evidence against him came after Armstrong lost a legal fight in US court to challenge USADA's system of hearing doping appeals.

"I'm not suggesting that they are all lying, but I am suggesting that each witness needs to have confrontation and cross-examination to test the accuracy of their information," Herman said.

Tygart noted that "Lance Armstrong was given the same opportunity to come forward and be part of the solution. He rejected it."

Herman attacked the credibility of USADA's findings, noting a federal probe ended with no charges filed against Armstrong, although USADA said it received no evidence from that investigation and was not seeking violations of law.

Herman also renewed Armstrong's objections to USADA's appeal system to a US arbitration panel and the Court of Arbitration for Sport (CAS), saying the inability to appeal to the US court system rather than CAS was "diabolical."

"The process is completely rigged. I don't care what Travis Tygart says," Herman said.

"Christians dealing with the lions in Rome had a better record than athletes dealing with USADA. It's a rigged system."