Ahead of the World Aquatics Championships in Fukuoka, Japan, Chinese national team swimmers Yan Zibei and Sun Jiajun spoke to China Daily show On Your Marks.

Having trained together since childhood, the two have become China's top breaststroke swimmers and both have refreshed the men's Asian 50m breaststroke record.

The 22-year-old Sun, the current Asian 50m breaststroke record holder, said captain Yan has always been like a big brother to him. Reciprocally, 27-year-old Tokyo Olympics silver medalist Yan says he's always thrilled to see Sun make progress in the pool.

Speaking of their goals for the forthcoming world championships and Asian Games, the two are determined to produce their best as they chase more glory for their country.