Funny how people have glossed over the one little kernel of truth in the posted material -- that there was some evidence of caffeine being a diuretic when ingested by people who don't normally have daily intakes of the substance. And that there is a natural resistance to it being a diuretic in people who have regular daily intakes of caffeine.

Whatever...

Caffeine has other effects. It is known to be an emergency treatment for asthmatics who have an attack and have no other medications available. The mix has to be very strong and be almost unpalatable, however.

A mate of mine back in Australia told me a story about his bike racing exploits which may or may not need to be taken with a grain of sugar.

He was involved in horse racing (this is about 40 years ago), and caffeine was supplied by vets in very large tablets for some specific reason that I forget now. But my friend was familiar with its uses and effects on race horses.

My mate also was a bike racer, and he was preparing for a 200km road event from Launceston to Hobart. He was pretty good at the sport, too, but wanted an edge. So he put two and two together, called up his veterinarian mate, got a hold of some of those big caffeine pills, and put them away the morning of the race.

They were effective, so effective that he streeted the field by half an hour. Remember, these were the elite road racers in the State.

Well, his performance was way above his previous averages. He was called to account, had to give a urine sample that gave away his ploy. He lost the title and was banned for life (or 10 year, which at the time might just as well be life).

He said he felt fantastic right through the event... but it took three or more weeks for his heart rate to return to normal.

I drink the instant powdered coffee, the dregs at the supermarket. So the effects on me are low-level, if any. The danger for me is the high-powered stuff served at the yuppie cafes we sometimes stop at. On one metric century ride in Melbourne last year, I ended up with severe indigestion, the shakes and a hugely elevated heart rate (that unfortunately did nothing for my riding performance). The effects subsided after about three hours, by which time we were on the return past the cafe. When someone asked if I wanted to stop, I said "no!".

High intakes of caffeine were banned in the Olympics for many years because of the performance edge it was perceived to give. An Australian fencing champ was banned after he returned an over-the-limit reading at the LA Games (I think). Caffeine has since been removed from the banned list, which must pee off the fencing guy...