[2] Sitnik made his official debut at the 2000 Summer Olympics in Sydney, competing in the men's super heavyweight division (130 kg).

Sitnik delivered a mediocre effort inside the ring after losing out three straight matches each to Turkey's Fatih Bakir by a sudden death point, Czech Republic's David Vála (0–3), and Israel's Yuri Evseichik, who eventually placed fourth at the end of prelim pool.

[3] At the 2004 Summer Olympics in Athens, Sitnik qualified for his second team, as a 29-year-old veteran, in the men's 96 kg class by rounding out the top eleven spots from the 2003 World Wrestling Championships in Créteil, France.

[4][5] He lost his opening match to Egypt's eventual gold medalist Karam Gaber, but redeemed himself to pull Kazakhstan's Asset Mambetov off the mat on his second bout with an effortless 3–0 decision.

Facing off against the host nation's Georgios Koutsioumpas, Sitnik could not exert enough power to subdue him into the ring, as he lost the match by a single-point deficit.