The United States set the world record in the 4x100 freestyle mixed relay, clocking 3 minutes, 18.48 seconds in the swim world championships.

Katie Ledecky delivered another masterclass in distance swimming to collect her sixth world title in the 1,500 metres freestyle on Tuesday and while she was never threatened in the final she felt her rivals were helping her push the sport forward.

Katie Ledecky stubbornly refused to give up her 800-meter freestyle crown Saturday at the world championships in Singapore, winning that race for a seventh consecutive time and fending off Canada's Summer McIntosh who led a field of talented young,