Marina Arzamasova, the world 800 metres champion in 2015, has been banned for four years after testing positive for a muscle growth agent, the Athletics Integrity Unit said on Friday. Arzamasova, 32, who also won a European silver medal in 2014, had been provisionally suspended in August last year after an anti-doping sample showed traces of ligandrol. Having run a personal best of 1min 57.54sec in 2015, she had not broke the two-minute barrier since 2016. kn/fby/gj/iwd