New Zealand's top swimmer Lauren Boyle says her congested schedule at the nationals in Auckland should hold her in good stead for international competitions later this year.
Boyle won the 400m freestyle last night, booking her place for August's World Championships in Russia.
Five other swimmers also qualified for the world champs during the first night of finals, including Glenn Snyders, Matthew Stanley, Corey Main and Bradlee Ashby.
New Zealand only produced five individual qualifiers for the last world championships two years ago.
The championships run over four days finishing on Friday, with Boyle competing in the 200m and 1500m freestyle today followed by the 100m and 800m tomorrow.
She says the tight turnaround between races is good preparation.
"That's just how the programme's worked out so I don't really have any choice. I think a lot of racing in a short space of time is pretty challenging and it's good to do that to prepare for tough situations later in the year."
Boyle won the 400m freestyle in 4:06.13, the ninth fastest time in the world this year.
She also dragged 20-year-old Emma Robinson through with a qualifying time that was just over a second inside the world champs mark.
The Commonwealth Games gold medallist says Robinson worked hard to seal her first individual qualifying effort for a world championships and has a bright future in the sport.
"Emma's a really exciting younger swimmer in New Zealand and she was on our team in Glasgow last year and it's great to have her back on again. She's been through a bit of a rough patch last year with her injury and it's great to see her perseverance and getting herself back to where she needs to be so congratulations to Emma."
Snyders booked a place to Kazan a decade after his first visit to the world championships, in his signature event, the 100m breaststroke.
The 28-year-old, now based in Los Angeles, clocked 1:00.35 to sneak under the qualifying time for the world championships by 0.1s.
Australian-based Stanley also nipped under the qualifying time when he went 3:50.73 in the 400m freestyle, which was 15/100ths of a second under the world championships mark.
The race was won by New Zealand-based Michael Dai from China in 3:50.64, although the London Olympic representative has yet to qualify to swim for this country.
Also last night six Para-Swimmers qualified for July's IPC World Championships in Glasgow, including Sophie Pascoe, who broke the 100m butterfly world record.