Even in winter temperatures of about 15 degrees Celsius (60F), a steady flow of hardy men and women wade into the brown waters of the Yangtze River in Wuhan and swim into the distance.

The tradition pre-dates Mao, but it was embedded in Wuhan's consciousness in 1966 when the then-73-year-old founder of communist China launched a political comeback with a carefully staged swim to prove he was in robust health.

All that stopped when the coronavirus emerged in Wuhan about a year ago. The city of 11 million people was placed into a strict lockdown in January that dragged on for 76 days. Now, the daily swimmers are back.