Coffee: the dose you cannot know

Caffeine has better evidence behind it than most things a fighter takes. Coffee is a poor way to deliver it, and separately, almost everything fighters believe about coffee and hydration is wrong.

Both need saying, because they point in different directions.

The dose problem

The variation comes from bean variety, roast, grind, brewing method, and how much actually went into the cup. Robusta carries more than arabica. Two drinks with the same name from the same shop can differ substantially, and neither will tell you which one you got.

For most people that does not matter. For somebody taking a stimulant with a real dose-response before a competition, it means you are guessing at the one variable you were trying to control.

If caffeine is part of your plan at a specific dose, take it as caffeine, where the number on the label is the number you swallow.

If coffee is part of your morning, that is a different thing entirely and needs no protocol.

Now the part everybody gets wrong

Coffee does not dehydrate you, and the belief that it does has been tested directly.

Fifty habitual coffee drinkers, consuming 3 to 6 cups a day normally, went through two 3-day trials. In one they drank 4 cups a day at four milligrams of caffeine per kilogram of body mass. In the other they drank water.

Food, fluid and activity were controlled, and total body water was measured before and after using deuterium oxide.

Across a wide range of blood and urine hydration markers, there were no significant differences between the two conditions.

The authors concluded that coffee consumed in moderation by habituated drinkers provides similar hydrating qualities to water.

So the fighter drinking 3 cups a day and adding extra water to compensate is compensating for something that is not happening.

The threshold, and where it sits

Caffeine does have a diuretic effect; the dose decides it, and there is a reasonably clear line.

Three milligrams per kilogram did not disturb fluid balance at all. Six did.

In fighter terms, for an 80 kilogram athlete: three milligrams per kilogram is about 240 milligrams, roughly 2 cups. Six is around 480 milligrams, or 4 to 5 cups taken together.

Two or 3 cups across a day is not a hydration problem. Five in one sitting is a different question, and so is a large pre-workout on top of them.

The 4-day trap

This is the part that matters most in this sport and almost nobody knows it.

Tolerance to the diuretic effect develops with regular intake, which is why the habitual drinkers in that study showed no difference against water. That tolerance is what protects them.

It also disappears quickly once intake stops. How quickly is not precisely established: a few days is the working figure from what is known about how fast caffeine tolerance and withdrawal effects appear, and I have not found a study that tested the diuretic tolerance specifically.

Treat 4 days as an estimate rather than a measured threshold.

The general principle applies here as everywhere in the last week. Fight week is not the time to change your relationship with a substance. If coffee is normal for you, keep it normal.

If it is not, this is not the week to start.

Half-life, and why fight night is different

Caffeine has an average half-life of around 5 to 6 hours in adults, with a very wide individual range that runs from about 2 hours to more than 10. Genetics account for much of that.

Most fights are in the evening, and most fighters have been awake since early morning after a difficult week. So caffeine goes in, reasonably and often correctly.

What gets forgotten is that it stays. A dose taken at eight in the evening is still substantially present at midnight and measurable into the night.

Sleep after a fight is the first part of recovery, and it is already difficult without help: adrenaline, soreness, a late finish, often travel. Caffeine on top of that can cost the night entirely.

And in a tournament format, where you compete again the next day, that night was the recovery. This is where the calculation changes most and where it is most often ignored.

Habituation and performance

Regular intake blunts the response. Somebody drinking coffee all day gets less from a pre-competition dose than somebody who does not.

The tempting conclusion is to withdraw for a week beforehand to restore sensitivity. I would not, and the evidence does not support it either: a short washout produces little or no measurable performance gain while reliably producing headaches, irritability and poor training at the worst point in the camp.

It also removes the diuretic tolerance described above at precisely the wrong moment.

The more useful version is to keep habitual intake moderate and consistent through camp rather than swinging it around in the final week.

Coffee through the phases

On the second row: coffee stimulates bowel activity in a lot of people, which is either useful or inconvenient depending on the hour and what you are trying to achieve that day.

In a week where gut content is a managed variable, that is worth timing deliberately rather than discovering.

What is actually in the cup besides caffeine

Black coffee is close to calorie-free, which is why it survives every phase of a camp untouched.

What goes in it is a different question, and it is the one that quietly costs people.

Three large lattes a day is somewhere between 400 and 700 calories that nobody writes down, because it is a drink rather than a meal.

Over an 8-week camp that adds up.

So know which of those four lines you are actually drinking, because most people would tell you they drink coffee and mean any of them.

Coffee in an away camp

Two things change when you travel and neither is obvious.

The coffee is different. A different country means different beans, different roast and often a different serving size, so the dose you have habituated to is not the dose you are now taking.

Somebody used to filter coffee who lands in a country of double espressos has changed his intake without deciding to.

And the timing is different, because your clock has moved. Coffee taken at what feels like morning may be landing in what your body still treats as the middle of the night, which is the opposite of helping you adapt.

The practical rule for the first days after an eastward flight is to keep caffeine to the early part of the local day and stop earlier than you would at home. Using it to push through afternoon fatigue on arrival is the most common way people extend jet lag rather than shorten it.

Decaf, and where it fits

Decaffeinated coffee is not caffeine-free, but it is close: usually a few milligrams a cup against 95 or more.

That makes it genuinely useful in two places. Late in the evening when the habit is what you want rather than the stimulant. And on a night before a fight, where the ritual of a coffee after dinner is part of somebody's routine and the caffeine is the part that will cost him the night.

The same applies to the tolerance question raised earlier. Switching to decaf in the evening while keeping normal coffee in the morning maintains habituation, which withdrawing entirely does not.

Tea, briefly, because the question follows

Black tea carries roughly a third to a half the caffeine of coffee, green tea less again, and both vary with steeping time in a way that is at least as unpredictable as coffee.

The practical use is as a step down rather than a substitute. Somebody who wants the ritual in the afternoon without the dose that costs him the evening is better served by tea than by another coffee, and better served by decaf than by either if the hour is late.

Herbal infusions carry no caffeine at all and are simply warm fluid, which in the final days is worth more than it sounds when plain water has become difficult to face.

Do not cut it for fight week

• If caffeine is part of the plan, take it as caffeine. Coffee is the wrong instrument for a dose you actually care about.
• Coffee does not dehydrate you at normal intakes if you drink it normally. Stop compensating for it.
• Do not cut it for fight week. You gain nothing and you lose the tolerance you built.
• Watch the total, not the cup. Two or three across a day is fine. Five in one sitting plus a pre-workout is a different drink.
• Think about the night after the fight before you take anything on the night of it.