Collings made her senior international debut at 1997 European Aquatics Championships in Seville.

Collings represented England and won a bronze medal in the 800 metres freestyle event, at the 1998 Commonwealth Games in Kuala Lumpur, Malaysia.

[10][11] Sarah represented Great Britain at the European Short Course Swimming Championships in 1996, 1998 and 1999 and won bronze medals in 1996 and 1998.

She also represented Great Britain at the World Short Course Championships in 1997 and 1999, finishing in the Top 8 both times.

At Masters level in 2016 Sarah swam in the European Masters Swimming Championships in London and became champion in the 35 - 39 age group at both the 400m and 800m Freestyle, and won Silver in the 200m in a British Record time.