Portia Bing's new routine is paying off

The 28-year-old broke her own national and resident records in the women's 400 metres hurdles at the Sir Graeme Douglas International in Auckland, clocking 55.50 seconds.

It's also a Commonwealth Games B standard time.

Bing says she's changed her race regime - for the first six hurdles she now does 14 strides instead of 15, and 15 strides for the last four.

She hopes she can run 55.40 by the end of the season, which is an automatic qualifier.