yes, but they were held later in the year when they were in Sydney - and for good reason, too I believe.

If one third of the competitors are unable to compete effectively (just supposing this is the case, as someone has mentioned) then this may be a valid reason for the date to be changed.

There may also be reasons why it can not be changed too - as you suggest - in which case Muslim competitors will need to consider whether it is appropriate to fast if they wish to compete. If I were organising an event where a significant number of potential participants could not attend due to the timing ... I would seriously consider other options ... I have found in the past however that people (including Muslims) are capable of being flexible, if they see it as reasonable.

I think there is a need to look at all factors and come to some consensus - and a sensible decision. That way its all clear and out in the open and no reasonable person will get their knickers in a twist about it.