Private Sub RunningSumSQL()
Dim db As Database
Set db = CurrentDb
Dim qry As QueryDef
Dim sSQL As String
On Error Resume Next
db.QueryDefs.Delete "temp"
On Error GoTo 0
sSQL = "SELECT R1.Event,(SELECT SUM(R2.Duration) FROM Running As R2 WHERE R2.Event < R1.Event) AS StartTime FROM Running As R1"
Set qry = db.CreateQueryDef("temp", sSQL)
DoCmd.OpenQuery qry.Name
End Sub