Andy Murray's gold medal triumph at the Olympics demonstrated his immense mental strength, according to Sky Sports expert Barry Cowan.
The British No 1 defeated Juan Martin del Potro in four sets to defend his Olympic singles title, following up his first gold medal at London 2012.
Murray's victory in Brazil came just a month after he claimed his second Wimbledon title and Sky Sports expert Cowan was hugely impressed with how the Scot maintained his high standards, despite a relentless schedule.