“Gyro”, as aficionados call it, originated in the 1980s when Hungarian ballet dancer Juliu Horvath began developing a system to help him recover from debilitating injuries. The result is a complex-looking piece of gym equipment – all weights, pulleys and a web of inter-connected ropes – that is designed to help users perform controlled spiralling movements to help keep their joints flexible and loose.

The exercise is particularly beneficial for people with bad backs or those who suffer physical injuries due to intense pressures on their bodies, such as dancers or sports people like Murray. Gyrotonic master trainer Elaine Puren explains: “The movements actually mimic the tennis swerves, so it would really help Murray to increase his core strength and flexibility.