Zabel, who is still active, and Aldag were support riders for the Telekom team when its top cyclists won the Tour de France — Bjarne Riis in 1996 and Jan Ullrich in 1997.

Speaking at a nationally televised news conference, Zabel and Aldag said they took the blood-boosting drug EPO. Both said they were ashamed of their actions and apologized. Zabel broke into tears during his confession.

"It was very difficult for me to tell my son, my parents," Zabel said. "I had lied to them."

Aldag is now sporting director of the T-Mobile team, previously known as Telekom. Zabel, a prominent sprinter, now rides for Milram.

"I started doping with EPO before the 1995 Tour de France," Aldag said.

Zabel said he took it in the first week of the 1996 Tour and did not repeat because he had some side effects. He said he has been riding clean since.

"I did it because it was possible. It was a test, it was a one-time thing," Zabel said.

Earlier this week, three other former Telekom riders admitted doping. Zabel is the only one still active in the sport.

In Denmark, Brian Holm, a former member of the Telekom team in the 1990s, confirmed that he also had taken EPO. Holm earlier admitted trying doping without naming the type of drug.

Zabel, 36, has 192 victories and has been one of Germany's top riders. He won the Milan-San Remo classic four times, has 12 stage wins at the Tour de France and took the points green jersey six times.

Aldag and Zabel said one of the reasons they took performance-enhancing drugs was the feeling that they wouldn't get caught.

"You can't be caught and everyone is doing it," Aldag said. "I doped because I could. For me, and probably for many others, EPO was this miracle drug."

They spoke at a news conference organized by T-Mobile at its headquarters in Bonn. Spokesman Christian Frommert said the company would remain a sponsor throughout its contract that ends in 2010.

T-Mobile team chief Bob Stapleton urged better doping tests.

"The system is ineffective," said Stapleton, who added that some riders were tested untold times.

Aldag will keep his current job with T-Mobile, Stapleton said.

Zabel said he told the Milram team two days ago that he intended to come clean.

"I don't know what the consequences will be, I have no idea what the future holds," he said.

Bert Dietz started the snowball of admissions Monday when he went on national television and acknowledged taking EPO, which enhances endurance by boosting the level of oxygen-rich blood cells in the system.

Dietz said he was introduced to EPO by Telekom team doctors Andreas Schmid and Lothar Heinrich, who also administered the substance when needed.

His admission followed claims by former Telekom massage therapist Jef d'Hont earlier this month that the two doctors gave EPO to some of the team's top riders, including Riis and Ullrich. Both have denied doping.

Ullrich, who retired in February, has been implicated in the Spanish doping scandal.

His lawyer, Peter-Michael Diestel, said Thursday there won't be any new statements from his client, who is under a criminal investigation in Bonn on fraud charges.

Later, Diestel said he would no longer be Ullrich's lawyer, without giving details.

Aldag said he never shared a room with Ullrich, his team captain at the time, and never used the same support staff.

"I cannot say anything about Ullrich doping or not doping," Aldag said.

Aldag said he first obtained EPO from d'Hont and later from "Freiburg," the University of Freiburg clinic that employed Schmid and Heinrich.

Schmid and Heinrich released separate statements to the media late Wednesday confirming their involvement with doping in the 1990s while they were working for Telekom. Both were fired by the clinic Thursday.

"I admit that, upon request, I made doping substances, especially EPO, available to certain riders since the mid-1990s," Schmid said in his statement. He said the doping practices did not involve the T-Mobile team.

Schmid said he never gave any drugs to riders without their knowledge.

Heinrich also confirmed he'd been involved in doping.

"I took part in the doping of riders in the course of my work as a sports doctor," he said.