He finished with 100 out of England's 265 for seven in their 77-run ICC Champions Trophy warm-up victory over Bangladesh at the NCC ground.

He and Ian Blackwell (56) ran plenty of exhausting ones and twos as well as mixing in some big shots in a 115-run fourth-wicket stand which came up at more than seven an over.

But Irani, who has suffered badly from cramp in the past, claimed he was in no real discomfort - and it was all down to his discovery of magnesium tablets.

He was introduced to the remedy by athletics coach Frank Dick and convinced of its effectiveness while seeking medical help on an injured knee in Germany.

His daily regime now includes drinking a litre-and-a-half of water before he goes to bed and taking 20 pills a day as well as regular doses of a 're-hydrating' potion.

It is all above board - which is just as well since blanket dope-testing will be in effect at next year's World Cup in which Irani hopes to be involved.

"Today there was a little bit of cramp, but it never really stopped me while I was batting. If I had not taken the magnesium I would have cramped up, no doubt," he said.

"They have been at it in Germany for 20 or 30 years - we are miles behind. Bayern Munich take it when they are playing away."

Conditions in Sri Lanka have already taken their toll on Rikki Clarke and Alec Stewart.

The young all-rounder passed out at nets earlier this week but was able to play against Bangladesh - which was more than could be said for Stewart, who remained behind at the team hotel with a stomach upset.

Gearing up for Wednesday's first Champions Trophy match against Zimbabwe, Irani showed no such frailty in hitting 12 fours in his 118-ball hundred.

Even so he admitted it was tough going at times.

"I had a little bit of cramp. But it was nothing major, and I felt all right bowling and fielding," he said.

"It is not the heat - nobody is getting sunburnt. It is just the air; there is no air."