Khaidarov returned home on November 8 after two months in custody -- a time he describes as "hell." He had been sentenced to a six-year jail term for extortion. He denies the charges.
He said his first priority is to recover from the abuse he suffered.
"Now I have to recover seriously. I feel changes have occurred to my organism. I cannot talk about that now. First I need to recover. Then it will be clear. But I have to say that I cannot live not working as a journalist," Khaidarov said.
Khaidarov was arrested in Jizzakh on September 14. Seconds before, he says, a woman he had met on the street slipped an envelope containing $400 into his pocket.
He says that after his arrest he was moved successively to four detention facilities.
First he was sent to a pretrial jail in Jizzakh, then transferred to the southern city of Khavas, then to a prison in Tashkent, the capital.
On October 5, Khaidarov was sentenced to six years in jail after a trial that Western rights groups condemned as a "parody of justice." He was then transferred to the Nawaiy prison colony.
He says living conditions in all those facilities was particularly harsh.
"I got very thin. Within a short period of time I lost probably some 12 kilograms. In jail we had to do compulsory exercises from 5 a.m. until 10 p.m," Khaidarov said. "Maybe it's because of this, because my organism was not used to those conditions, I now feel pain in my bones and head."
Conditions worsened after he was moved to Tashkent and then to Nawaiy.
There, Khaidarov said, he endured a form of torture that consists of having a prisoner march through two ranks of prison guards who beat the prisoners with truncheons or iron bars. This exercise is named after the Russian word for "breaking."
The journalist said he was physically and psychologically harassed, both during the investigation and after his trial.
His wife, Munira Khaidarova, was allowed to see her husband in prison on September 23. Three days later, Khaidarov's sister Nortoji shared her concern with RFE/RL's Uzbek Service.
"[The prison guards] hardly gave [Munira] five minutes. They kept rushing her. She told us she found [Ulugbek] in bad shape. She says he didn't seem to be in his right mind. His eyes were unfocused. His mouth was twisted," Khaidarov said. "He had lost a great deal of weight. He didn't seem to know what he was saying. He kept repeating: 'I know nothing, I know nothing,' and 'everything's alright, everything's alright.'"
On November 7, the appeals chamber of the Jizzakh city court cleared Khaidarov of all charges and ordered his release. He was set free the following day.
The Paris-based Reporters Without Borders press freedom watchdog on November 8 welcomed Khaidarov's "unexpected release."
But the group said many Uzbek journalists remain in custody, including Khaidarov's friend Jamshid Karimov.
Karimov, who is the nephew of Uzbek President Islam Karimov, disappeared in Jizzakh on September 12.
He is believed to have been arrested by the Uzbek secret police and sent to a psychiatric hospital.
Khaidarov's liberation coincided with talks Uzbek Foreign Minister Vladimir Norov had in Brussels this week with European Union officials.
The EU is due to decide on November 13 whether to extend the sanctions imposed on Uzbekistan following last year's military crackdown in Andijon.
Some rights campaigners have suggested Kaidarov's release is linked to the upcoming EU decision. Others -- that it is a consequence of the visit German Foreign Minister Frank-Walter Steinmeier made in Uzbekistan earlier this month.