Wanaka has a new age-group world champion in ice swimmer Rachel Armstrong.

Armstrong (39) ploughed her way to victory in her age-group 1000m race at Sameons in France on Saturday, finishing in 15min 7.26sec.

It was a substantial personal best in sub 5degC conditions for Armstrong, who qualified for the worlds with a 15min 20.79sec performance in the Ice Mile at New Zealand’s first ice swimming nationals in Alexandra in July.

Seven swimmers represented New Zealand at the world championships in France on January 12›15. The other six swimmers were from the North Island.

They trained in England at Falcon Lake in the Castle Ashby Estate for five days before the competition to get used to temperatures close to 5degC.

Team members were selected after the championships in Alexandra in July last year, when several swimmers broke age›group records.

Ice swimming is an extreme sport with strict safety rules. Swimmers compete in temperatures of 5degC or lower, unassisted, wearing one standard swimming costume, one pair of goggles, and one standard swimming silicon cap.

Ice swimming . . . the World Ice Swimming Championships venue in Samoens, France. PHOTO: SUPPLIED