'My baby is the source of my strength'

"A person can gradually get used to the physical tiredness when it becomes routine, but mentally, you always feel you are lacking something," said Hu Ranran, a 30-year-old mother.

Hu lives in Shunyi district, 30 kilometers northeast of downtown Beijing, but her office is in the central business district in the downtown.

Her working day used to start with a 10-minute bus ride to the nearest subway station, followed by 90 minutes on the subway - changing lines twice - and then a 10-minute walk to her office.