Erfurt doctor Mark S., as the main defendant in Germany's largest blood doping trial, has made a comprehensive confession for years.
In a statement read out by his lawyers, he admitted manipulation since 2012.
Since then, he has mainly looked after winter sports enthusiasts and cyclists.
He pointed out that it was not about money and that he had worked to break even.
"I have not made a profit with doping," the statement said.
From the athletes he received 5,000 euros per season as a basic amount for medical care, more intensive measures cost more.
He had high expenses due to special equipment for blood preparation as well as travel and hotel expenses.
In addition, he contradicted the accusation that the treatments put the athletes in danger: "It was always important to me that the athletes did not harm their health."
On a case on the prosecution that he administered a dangerous drug to a mountain biker, he said she knew he had not tested the drug.
The public prosecutor's office accuses Mark S., among other things, of dangerous bodily harm.
The process involves almost 150 offenses that S. is said to have committed.
He conceded most of them, but disagreed in about a dozen of the cases listed.
In the first two weeks of the trial, two of the doctor's helpers testified, the nurse Diana S. and the paramedic Sven M. They confirmed the results of the investigations in the so-called "Aderlass Operation".
"Lost sight of the fact that I harm sport"
The doctor had asked them to take blood from athletes in various places and give them to them.
Mark S.'s father also said, as another defendant, that he knew about the manipulation of his son.
Only the fifth defendant, the building contractor Dirk Q., has not yet commented.
Like Mark S., he has been in custody since the beginning of 2019 because, according to the prosecutor, he also took blood from athletes and injected it again.
Among other things, this happened during the 2018 Winter Olympics in Pyeongchang.
At the beginning of the trial, his lawyer demanded that the case be closed for alleged wrongdoing.
Mark S. also reported on his time as a team doctor at the Gerolsteiner and Milram cycling stables between 2007 and 2010. Although both teams had been disbanded due to doping cases, he denied having been involved in manipulation at the time.
"I can't say why I decided to use autologous blood doping afterwards. The fascination and love for sport were the driving force behind this decision," he read.
He stated that he had heard of doping methods, some of which were adventurous, but that he himself wanted to help the athletes "at the highest level".
"Unfortunately, I have lost sight of the fact that this is damaging the sport."
The trial is the largest German doping trial in years.
A verdict is expected shortly before Christmas.
The investigations began in January 2019 according to the ARD documentary
Die Gier nach Gold
and statements by Austrian cross-country skier Johannes Dürr.
At the end of February there were two raids at the Nordic World Ski Championships in Seefeld and Erfurt, where Mark S. was arrested.
Dürr was later sentenced to a suspended sentence of 15 months.