But he intends to carry on with his marathon sermon at the parish church for 36 hours ending at 0630BST on Saturday.
The Reverend Chris Sterry, vicar at Whalley in Lancashire, has broken the previous record for an unscripted speech of 27 hours and 30 minutes.
But he intends to carry on with his marathon sermon at the parish church for 36 hours ending at 0630BST on Saturday.
He hopes his preaching will raise £2,000 for church funds.
The 46-year-old vicar is not allowed to repeat himself, talk nonsense, and is not allowed to pause for more than 10 seconds.
He can take a break of 15 minutes every eight hours.
Two referees working four-hour shifts are ensuring that the rules are observed.
Mr Sterry warned that parishioners might have to turn away while he uses his "pulpit potty".
Fatigue fought
He has not slept but fights fatigue by drinking caffeine-filled drinks.
He also sips orange juice and sucks throat lozenges to soothe his vocal chords.
Mr Sterry began preaching on the Book of Genesis.
Before the sermon began he said: "As a former lecturer on the Old Testament I am looking forward to unlimited opportunity to talk about one of my great enthusiasms."
A spokesman said he was in good spirits.
"There were more than 100 people in church when he broke the record and if he looks like he's about to drop off, they heckle him," he said.