Nanjing seniors find key to fitness in stone locks

Throwing stone locks to stay in shape has been popular for years among some seniors in Nanjing, East China's Jiangsu province.

In Nanjing's Yixianqiao Sports Park, seniors throw the stone locks into the air, grab them, and throw them at each other to keep fit.

"Not a single person has been hit on the foot by the stone locks," said Liang Zhenxing, who has been practicing with stone locks since he retired at 60.

"It's easy to learn and helps accelerate muscle growth," said the 75-year-old resident. "I started with a 10-kilogram stone lock. Now I'm practicing with a 22.5-kilogram one."

He said that like many friends who throw stone locks, he is very healthy and will keep exercising and challenging himself.