“The daily pace he kept for 30 years meant that many weeks he was speaking more than he was sleeping.”
John Piper speaking recently about the tireless preaching of George Whitefield, whose sum total of sermons and exhortations during the span of his ministry reached upward of 30,000.
Tony Reinke 
Unbelievable stuff about whitefield, I was blown away when Piper quoted one of Whitefields friends who said:
“Who would think it possible that a person . . . should speak in the compass of a single week (and that for years) in general forty hours, and in very many, sixty, and that to thousands; and after this labor, instead of taking any rest, should be offering up prayers and intercessions, with hymns and spiritual songs, as his manner was, in every house to which he was invited.”