AUSTIN, Texas -- Lance Armstrong stepped down as chairman of his Livestrong cancer-fighting charity and Nike severed ties with him as fallout from the doping scandal swirling around the famed cyclist escalated Wednesday.

Armstrong announced his move at the charity in an early-morning statement. Within minutes, Nike said that it would end its relationship with him "due to the seemingly insurmountable evidence that Lance Armstrong participated in doping and misled Nike for more than a decade."

Nike said it will continue to support Livestrong.

The U.S. Anti-Doping Agency released a massive report last week detailing allegations of widespread doping by Armstrong and his teams when he won the Tour de France seven consecutive times from 1999 to 2005.

The document's purpose was to show why USADA has banned him from cycling for life and ordered 14 years of his career results erased – including those Tour titles. It contains sworn statements from 26 witnesses, including 11 former teammates.

Armstrong, who was not paid a salary as chairman of the Lance Armstrong Foundation, will remain on its 15-member board. His duties leading the board will be turned over to vice chairman Jeff Garvey, who was founding chairman in 1997.

"This organization, its mission and its supporters are incredibly dear to my heart," Armstrong said in a statement. "Today therefore, to spare the foundation any negative effects as a result of controversy surrounding my cycling career, I will conclude my chairmanship."

Foundation spokeswoman Katherine McLane said the decision turns over the foundation's big-picture strategic planning to Garvey. He will also assume some of the public appearances and meetings that Armstrong used to handle.

Armstrong strongly denies doping, but did not fight USADA accusations through arbitration, saying he thinks the process is unfair. Once Armstrong gave up the fight in August and the report came out, crisis management experts predicted the future of the foundation, known mainly by its Livestrong brand name, would be threatened. They said Armstrong should consider stepping down to keep the charity from getting dragged into a debate over doping.

Armstrong's inspiring story of not only recovering from testicular cancer that had spread to his lungs and brain but then winning the world's best-known bike race helped his foundation grow from a small operation in Texas into one of the most popular charities in the country.

Armstrong drew legions of fans – and donations – and insisted he was drug free at a time when doping was rampant in professional cycling. In 2004, the foundation introduced the yellow "Livestrong" bracelets, selling more than 80 million and creating a global symbol for cancer awareness and survivorship.

"As my cancer treatment was drawing to an end, I created a foundation to serve people affected by cancer. It has been a great privilege to help grow it from a dream into an organization that today has served 2.5 million people and helped spur a cultural shift in how the world views cancer survivors," Armstrong said.

As chairman, Armstrong did not run the foundation's day-to-day operations, which are handled by Livestrong president and chief executive Doug Ulman.

Ulman had said last week that Armstrong's leadership role would not change. Armstrong's statement said he will remain a visible advocate for cancer issues, and he is expected to speak at Friday night's 15th anniversary gala for Livestrong in Austin.

"My family and I have devoted our lives to the work of the foundation and that will not change. We plan to continue our service to the foundation and the cancer community. We will remain active advocates for cancer survivors and engaged supporters of the fight against cancer," Armstrong said.

CharityWatch, which analyzes the work of approximately 600 charities, lists the foundation among its top-rated organizations. That status normally goes to groups which "generally spend 75 percent or more of their budgets on programs, spend $25 or less to raise $100 in public support, do not hold excessive assets in reserve" and disclose of basic financial information and documents.

Livestrong says it had functional expenses totaling nearly $35.8 million last year and 82 percent of every dollar raised went directly to programs, a total of more than $29.3 million.

The foundation reported a spike in contributions in late August in the days immediately after Armstrong announced he would no longer fight doping charges and officials moved to erase his Tour victories.

Daniel Borochoff, founder and president of Chicago-based CharityWatch, said last week it may take some time for donors to digest the allegations against Armstrong.

"Individuals that admire and support an individual who is later found out to be severely tarnished, don't want to admit it, don't want to admit that they've been duped," Borochoff said. "People, though, do need to trust a charity.

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  • Lance Armstrong, Floyd Landis

    In this July 24, 2004, file photo, overall leader Lance Armstrong, right, of Austin, Texas, follows compatriot and teammate Floyd Landis, left, in the ascent of the La Croix Fry pass during the 17th stage of the Tour de France cycling race between Bourg-d'Oisans and Le Grand Bornand, French Alps.

  • Lance Armstrong

    Lance Armstrong negotiates the route on the way to his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from professional cycling.

  • Lance Armstrong

    FILE - In this Feb. 15, 2011, file photo, Lance Armstrong pauses during an interview in Austin, Texas. Armstrong said on Thursday, Aug. 23, 2012, that he is finished fighting charges from the United States Anti-Doping Agency that he used performance-enhancing drugs during his unprecedented cycling career, a decision that could put his string of seven Tour de France titles in jeopardy. (AP Photo/Thao Nguyen, File)

  • ARMSTRONG

    FILE - This July 25, 1999 file photo shows Tour de France winner Lance Armstrong being kissed by his wife Kristin, left, and his mother Linda after the 20th and final stage of the Tour de France cycling race in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Laurent Rebours, File)

  • Lance Armstrong

    FILE - In this July 6, 2010, file photo, Lance Armstrong grimaces prior to the start of the third stage of the Tour de France cycling race in Wanze, Belgium. Armstrong said on Thursday, Aug. 23, 2012, that he is finished fighting charges from the United States Anti-Doping Agency that he used performance-enhancing drugs during his unprecedented cycling career, a decision that could put his string of seven Tour de France titles in jeopardy. (AP Photo/Christophe Ena, File)

  • ARMSTRONG JALABERT MC EWEN

    FILE - This July 28, 2002 file photo shows Tour de France winner Lance Armstrong, center, flanked by best sprinter Robbie McEwen, of Australia, right, and best climber Laurent Jalabert, of France, after the 20th and final stage of the Tour de France cycling in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Peter Dejong, File)

  • ARMSTRONG

    FILE - This July 23, 2000 file photo shows Tour de France winner Lance Armstrong riding down the Champs Elysees with an American flag after the 21st and final stage of the cycling race in Paris. The superstar cyclist, whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Laurent Rebours, File)

  • Lance Armstrong

    FILE - In this Feb. 28, 2011, file photo, former cycling champion Lance Armstrong smiles during a news conference at the Cedars-Sinai Hospital in Los Angeles. The U.S. Anti-Doping Agency on Wednesday, July 11, 2012, granted Armstrong an extension of up to 30 days to contest drug charges while the seven-time Tour de France winner challenges the case in federal court. (AP Photo/Damian Dovarganes, File)

  • Lance Armstrong, Ivan Basso, Jan Ullrich

    FILE - In this July 24, 2005 file photo, Lance Armstrong gestures from the podium after winning his seventh straight Tour de France cycling race, as second-placed Ivan Basso of Italy, left, and third-placed Jan Ullrich of Germany, look on, after the 21st and final stage of the race in Paris. Armstrong, he superstar cyclist whose stirring victories after his comeback from cancer helped him transcend sports, chose not to pursue arbitration in the drug case brought against him by the U.S. Anti-Doping Agency. That was his last option in his bitter fight with USADA and his decision set the stage for the titles to be stripped and his name to be all but wiped from the record books of the sport he once ruled. (AP Photo/Christophe Ena, File)

  • Lance Armstrong

    Lance Armstrong, right, chats with other riders at the start line of the Power of Four mountain bicycle race at the starting line in Snowmass Village, Colo., early Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from the sport.

  • Lance Armstrong, Keegan Swirbul

    Lance Armstrong, front, talks to reporters after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. Race-winner Keegan Swirbul, 16, of Aspen, left, clapso his hand.

  • Lance Armstrong

    Lance Armstrong guides his bicycle down the steps after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo., on Saturday, Aug. 25, 2012. The race is the first public appearance for Armstrong since the U.S. Anti-Doping Association stripped him of his seven Tour de France championships and banned him for life from professional cycling.

  • Lance Armstrong

    Lance Armstrong listens at the World Cancer Congress in Montreal Wednesday, Aug. 29, 2012.

  • Lance Armstrong

    Lance Armstrong speaks to delegates at the World Cancer Congress in Montreal Wednesday, Aug. 29, 2012.

  • Lance Armstrong

    Lance Armstrong signs autographs for supporters after a run, Wednesday, Aug. 29, 2012, on Mont Royal Park in Montreal.

  • Lance Armstrong

    Lance Armstrong talks to supporters prior to a run, Wednesday, Aug. 29, 2012, on Mont Royal Park in Montreal.

  • Lance Armstrong

    Lance Armstrong competes in the Rev3 Half Full Triathalon Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong

    Lance Armstrong crosses the finish line of the Rev3 Half Full Triathalon Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong, Isabelle Armstrong, Grace Armstrong

    Lance Armstrong crosses the finish line of the Rev3 Half Full Triathalon with his ten-year-old twin daughters Grace, left, and Isabelle, right, Sunday, Oct. 7, 2012 in Ellicott City, Md. Armstrong joined other cancer survivors in the event which raised funds for the Ulman Cancer Fund for Young Adults.

  • Lance Armstrong

    In this Aug. 25, 2012, file photo, cyclist Lance Armstrong prepares to take part in the Power of Four mountain bicycle race in Snowmass Village, Colo. With U.S. anti-doping officials set to issue their report on Armstrong's case, a lawyer for the cyclist on Tuesday again criticized the process which led to himn being banned from the sport for life.

  • Lance Armstrong

    In this Aug. 25, 2012, file photo, Lance Armstrong considers a question from a reporter after his second-place finish in the Power of Four mountain bicycle race at the base of Aspen Mountain in Aspen, Colo.

  • Lance Armstrong

    This April 1, 2012 file photo shows seven-time Tour de France champion Lance Armstrong grimacing during a news conference after the Memorial Hermann Ironman 70.3 Texas triathlon in Galveston, Texas.

  • This is a July 24, 2005, file photo showing overall leader Lance Armstrong, of Austin, Texas, surrounded by press photographers, signaling seven, for his seventh straight win in the Tour de France cycling race, prior to the start of the 21st and final stage of the race, between Corbeil-Essonnes, south of Paris, and the French capital.

  • Lance Armstrong

    This July 5, 2004 file photo shows U.S. Postal Service team leader and five-time Tour de France winner Lance Armstrong, third from right, framed by his teammates as the pack rides during the second stage of the 91st Tour de France cycling race between Charleroi and Namur, Belgium.

  • Lance Armstrong, George Hincapie

    This March 21, 2009 file photo shows Lance Armstrong, of the United States, beside fellow countryman George Hincapie, left, during the Milan-San Remo cycling classic in San Remo, Italy.

  • Lance Armstrong

    Lance Armstrong waits for the start of the Ironman Panama 70.3. triathlon in Panama City, Panama.

  • Lance Armstrong

    This May 11, 2012, file photo shows cycling great and cancer survivor Lance Armstrong at a rally in favor of Proposition 29, at Children's Hospital in Los Angeles.

  • Lance Armstrong

    Lance Armstrong (center) leads the pack coming to Jack's restaurant in Pleasant Grove, Ala., Friday, April 27, 2012,, on the fourth day of the Bo Bikes Bama charity bike ride on the one-year anniversary of the deadly Alabama tornadoes.

  • Lance Armstrong

    From left, Bo Jackson, Lance Armstrong, Picabo Street and Ken Griffey, Jr. gather for a photo as the greeted fans and signed autographs in Pleasant Grove, Ala., Friday, April 27, 2012,, on the fourth day of the Bo Bikes Bama charity bike ride on the one-year anniversary of the deadly Alabama tornadoes. Jackson and about 140 bicyclists and the celebrity bikers rode from Cordova, Ala. to Bessemer, Ala. on Friday.

  • Lance Armstrong

    Lance Armstrong waits for the start of the Memorial Hermann Ironman 70.3 Texas triathlon, Sunday, April 1, 2012, in Galveston, Texas. Armstrong finished in seventh place.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.

  • Lance Armstrong

    Lance Armstrong competes in the Ironman Panama 70.3. triathlon in Panama City, Sunday Feb. 12, 2012. The race consists of a 1.2-mile swim, a 56-mile bike ride and a 13.1-mile run.