Swimming lessons in some Staffordshire schools should stop during Ramadan to ensure Muslim pupils "do not swallow water", a council has suggested.
Stoke-on-Trent City Council has issued an 11-page Ramadan guide for schools to help pupils who may be fasting when the school year starts in September.
It said swimming was acceptable to Muslims but posed a high risk of swallowing water that may break a fast.
Islam requires Muslims to fast from dawn until dusk for one month per year.
This year's Ramadan is expected to begin on or around 11 August and finish 30 days afterwards.
'Disrupt sleeping patterns'
The council guide states: "Schools with a significant number of Muslim pupils should try to avoid scheduling swimming lessons during Ramadan to remove unnecessary barriers to full participation."
It also suggests re-scheduling sex education classes during the holy lunar month, as Muslim followers who have reached puberty are required to avoid sexual thoughts during this period.
Because of the religious requirement for Muslims to avoid eating during sunlight hours, some pupils get up before dawn to eat with their families.
Schools have been advised this can disrupt pupils' sleeping patterns and it suggests examinations could be re-scheduled to reflect their lower levels of concentration.
"The overriding consideration should be that children do not feel disadvantaged in school activities because of their religious observance," the council said.
It said the document, produced by its Standing Advisory Council on Religious Education, was based on information from the Muslim Council of Britain, (MCB) an umbrella organisation that claims to represent up to 500 Muslim groups in the UK.
A spokesman for the MCB said: "[We] issued an advisory document which highlighted parental concerns from a broad spectrum of Muslim traditions.
'Out of proportion'
"These were guidelines designed to be helpful, to understand the concerns of certain Muslim parents. They are not obligatory or in no way directive. At the end of the day, the educational development and the welfare of the pupil is paramount."
But Terry Sanderson, president of the National Secular Society said the guidance is out of proportion.
"Surely it should be possible for Muslim pupils to be withdrawn from those elements of the school day that they don't want to participate in without imposing these restrictions on everybody, Muslim or not.
"It is wrong that everyone in schools should be forced to observe Islamic laws when they may have no meaning for them.
"Rearranging the whole school routine for a whole month to satisfy the religious needs of a few is totally out of proportion."