 Complete the following phrase:  Vladimir Polyakov ; born 17 April 1960 is a retired pole vaulter who represented the Soviet Union and later Russia. On 26 June 1981 he managed to clear 5.81 metres, beating Thierry Vignerons six-day-old world record. Two years later Polyakov lost the record to Pierre Quinon, who jumped 5.82. Polyakov won a silver medal at the 