Premier League legends Robert Pires and Marcel Desailly were left gasping for air after undertaking the 'Referee Pressure Test' this week.
The challenge, designed by TAG Heuer to show just how hard referees have to work in top-flight matches, saw the two ex-players racing between sets of cones.
After each sprint, the players were asked tough quiz questions, to replicate how officials have to also use their brain during exercise to make the correct decisions.
After a series of sprints and questions, the scores were tied level at 5-5 but Chelsea legend Desailly was the man who eventually came out on top.