He entered the ranking of the top ten athletes in the world in the 1990 season, setting a best of 5.80 m (19 ft 1⁄4 in).[2] Following a second-place finish at the Soviet Indoor Athletics Championships, Ryzhenkov was then chosen to represent the Soviet Union at the 1991 IAAF World Indoor Championships.[3] On his first major appearance he claimed the silver medal with a vault of 5.80 m (19 ft 1⁄4 in), beaten only by his more illustrious compatriot Sergey Bubka.[4][5][6]
Later that month in San Sebastián he cleared a new best of 5.91 m (19 ft 4+1⁄2 in), while finishing runner-up to Bubka again, who broke the world record.[7] Ryzhenkov's mark made him the second best performer in the world that indoor season.[8] He continued to compete on the circuit alongside Bubka and placed third in Malmö while his countryman again broke the world record.[9]
Ryzhenkov's personal best ranks him within the top twenty all-time performers in the indoor pole vault.[3] He did not compete internationally after the dissolution of the Soviet Union at the end of 1991.