YINCHUAN, Aug. 2 (Xinhua) -- This summer, gymnasiums in Yinchuan, capital city of northwest China's Ningxia Hui Autonomous Region, are crowded with people. Teenagers are learning swimming, dancing and roller skating while their parents are playing badminton or tennis on seperate fields.

"The capacity of our swimming class for this summer vacation is 240, but it filled up soon upon the opening of registration," said Jinwei, a swimming coach in the Ningxia Qinshui Sports Center.

Summer vacation has become a "golden time" for teenagers to master key extracurricular skills. In recent years, sports training centers offering classes such as basketball, dancing, rock climbing and roller skating have become more popular among Chinese parents and their children.

Qiu Haimei has been taking her two sons to Qinshui Sports Center every afternoon over the summer. The four-year-old Yang Zhaoyang is taking an exciting balance-bike class in protective clothing while Qiu is playing badminton along with her eldest son, who has just finished a Chinese calligraphy class.

"Since taking the class, my little son has given up the bad habit of playing with his smart phone before sleeping," said Qiu, adding that playing badminton helped release the pressure from working and learning for her and her eldest son, and her neck pain was also relieved.

Although she is busy with work, Wang Fang accompanies her 12-year-old daughter Qian Duoduo to swimming class at least three times a week. According to Wang, she used to put her daughter's academic records above all other things, but says she has now realized the importance of a healthy lifestyle for her child.

"She has made a lot of friends in the swimming class, and has become tougher and more optimistic," said Wang.

With social media playing an ever-bigger role in our lives, more and more teenagers are suffering from shortsightedness and obesity. In addition, quite a lot of middle-aged people are affected by high blood glucose, backaches or other illnesses caused by a sedentary lifestyle.

In recent years, the Chinese government has issued a series of documents emphasizing national fitness, causing "Fitness-for-All" programs to sweep throughout China and leading to a surge in enthusiasm for sports activities.

Before this year's summer vacation, the Chinese Ministry of Education published an official document requiring relavent departments to make use of existing resources such as gymnasiums, museums and cultural centers to provide more extracurricular activities for primary and secondary school students.