Ning Zetao of China celebrates after the awarding ceremony of the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China attends the awarding ceremony of the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China celebrates during the awarding ceremony of the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia August 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia August 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China cheers for himself before the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia August 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China reacts after the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia August 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia August 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China reacts after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China reacts after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China reacts after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China reacts after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Zhang Fan)

Ning Zetao of China competes during the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China celebrates after winning the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Athletes compete during the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao of China claimed the title with 47.84 seconds. (Xinhua/Dai Tianfang)

Ning Zetao of China competes during the men's 100m freestyle final at the 2015 FINA World Championships in Kazan, Russia, Aug. 6, 2015. Ning Zetao claimed the title with 47.84 seconds. (Xinhua/Pavel Bednyakov)