Calling himself "deeply flawed," now-disgraced cyclist Lance Armstrong says he used an array of performance enhancing drugs to win seven Tour de France titles followed by years of often angry denials.

"This is too late, it's too late for probably most people. And that's my fault," he said in an interview aired Thursday night. "(This was) one big lie, that I repeated a lot of times."

Armstrong admitted using testosterone and human growth hormone, as well as EPO -- a hormone naturally produced by human kidneys to stimulate red blood cell production, which increases the amount of oxygen that can be delivered to muscles, improving recovery and endurance.

In addition to using drugs, the 2002 Sports Illustrated Sportsman of the Year admitted to Oprah Winfrey that he took blood transfusions to excel in the highly competitive, scandal-ridden world of professional cycling. Doping was as much a part of the sport as pumping up tires or having water in a bottle, Armstrong said, calling it "the scariest" that he didn't consider it cheating at the time.

The same man who -- as he has throughout and after his career -- insisted he'd passed each of the "hundreds and hundreds of tests I took" contended in the interview that he wouldn't have won without doing what he did, and which he suspected many other cyclists did as well. While Armstrong didn't invent the culture of doping in cycling, he said, he admitted not acting to prevent it either.

"I made my decisions," Armstrong said. "They are my mistakes."

The first installment in his interview, which was conducted earlier this week with the talk-show host, aired Thursday on the OWN cable network and on the Internet. The second and final installment will be broadcast Friday night.

Armstrong admitted he was "a bully ... in the sense that I tried to control the narrative," sometimes by spewing venom at ex-teammates he thought were "disloyal," as well as suing people and publications that accused him of cheating.

He described himself as "a fighter" whose story of a happy marriage, recovery from cancer and international sporting success "was so perfect for so long."

"I lost myself in all of that," he said, describing himself as both a "humanitarian" and a "jerk" who'd been "arrogant" for years. "I was used to controlling everything in my life."

Armstrong's history of alleged doping has tarred the cancer charity Livestrong that he founded, as well as tarnished his once-glowing reputation as a sports hero.

Those who spoke out against Armstrong at the height of his power and popularity not only felt his wrath, but the wrath of an adoring public.

Now, with Armstrong stripped of endorsement deals and his titles, those who did speak out are feeling vindicated.

"Eleven years of bullying and threats," Kathy LeMond, the wife of cyclist Greg LeMond -- one of Armstrong's earliest targets and the first American to win the Tour de France -- wrote on Twitter. "LA is now the Greatest Fraud in the History of Sports."

In his interview with Winfrey, Armstrong said he understands why many could be upset that it took him so long to speak out, especially after going on the offensive for so long. He said he's reached out in recent days to several people who publicly accused him of doping and then were attacked -- and in some cases sued -- by him.

And the former athletic icon also conceded he'd let down many fans "who believed in me and supported me" by being adamant, sometimes hurtful and consistently wrong in his doping denials.

"They have every right to feel betrayed, and it's my fault," he said. "I will spend the rest of my life ... trying to earn back trust and apologize to people."

Armstrong stripped of Olympic bronze

Not only is Armstrong no longer officially a Tour de France winner -- he's no longer an Olympic medalist, either.

The International Olympic Committee has stripped Armstrong of the bronze medal he won in the men's individual time trial at the 2000 Olympic Games and asked him to return the award, an IOC spokesman said Thursday. The committee has not yet decided whether to bestow the bronze on fourth-place finisher Abraham Olano of Spain or to leave the slot vacant, IOC spokesman Andrew Mitchell told CNN.