Schoolchildren in China face an ever-increasing workload as parents look to give them an advantage, as Zou Shuo reports.

In recent years, the bulging, overweight school bags of China's primary and middle school students in urban areas have been increasingly carried by their grandparents or on trolleys.

However, the academic burden on children's shoulders is becoming heavier as they shuttle between different after-school classes designed to give them a head start.

In addition to the two-hour extracurricular classes many students attend when school ends at 3:30 pm on week days and at weekends, the winter and summer vacations have become a third semester for overworked children.

The problem has become so acute that the Ministry of Education has ordered schools to reduce the amount of homework given to students during the period of compulsory education, which lasts from first to ninth grade.

The move is intended to guarantee that primary school students get 10 hours of sleep a night, while middle school students should get nine hours, as relief from after-school training programs that are making their lives more stressful.

In 2016, more than 137 million primary and secondary school students attended extracurricular classes, which had a combined market value of more than 800 billion yuan ($127 billion), according to the Chinese Society of Education, which is overseen by the Ministry of Education.

A different study by the China National Children's Center found that 48 percent of students attend after-school classes, and more than half said they rarely have time to play with friends.

More than 90 percent of the 8,847 children surveyed said most conversations they have with their parents are about academic performance, while 14 percent said they had never spoken with their next-door neighbors.

Experts said that instead of blaming parents and providers of extracurricular classes for the situation, only a thorough overhaul of China's exam-oriented education system would offer a real solution and reduce the burden on students.