At the 2008 Summer Olympics in Beijing, Polyakov competed in two individual events with only four days in between. He achieved FINA A-standards of 1:01.43 (100 m breaststroke) and 2:12.29 (200 m breaststroke) at the Japan International Swim Meet in Chiba. On the first day of the Games, Polyakov missed out on the semifinals in the 100 m breaststroke by nine-hundredths of a second, finishing with a time of 1:00.80. Four days later, in the 200 m breaststroke, Polyakov posted a qualifying time of 2:10.83 to earn the eleventh spot in the prelims, qualifying for the semifinals. In the following morning session, Polyakov could not match his best results from Athens four years earlier, as he placed fifteenth in the semifinals at 2:11.87.