Koba began her career as a track specialist in her early twenties. She was the 1500 metres gold medallist at the 1980 European Athletics Indoor Championships on her major international debut.[1] She achieved a lifetime best of 4:01.66 minutes for that event in July 1981.[2] After a break from competition, she returned in her thirties and began to make an impact at national level in 1989 with runner-up finishes at the Brothers Znamensky Memorial and both the 3000 metres and 5000 metres at the Soviet Athletics Championships (behind Tatyana Pozdnyakova). The following year, a win at the Brothers Znamensky Memorial and third place at the national championships brought her selection for the Goodwill Games, where she placed ninth in the 5000 m.[3]
In her later career, Koba moved into road running, competing in a variety of lower level races in Germany, Austria and the Netherlands and regularly placing within the top five of those competitions. She retired from competition in her late forties.[3]