Most scientific studies are false, but at least when they match up to personal experience I can give them some credibility as maybe being true.
2022-01-15, by Ross Pomeroy. Emphasis added.
Late last year, a team of scientists from Brazil published the results of a study exploring the effects of a performance-enhancing drug on fourteen male recreational cyclists. The benefits were astounding. Subjects completed a sixteen kilometer time trial more than 40 seconds faster when they had ingested the drug compared to when they had just taken a placebo pill, a remarkable difference considering the trial took on average around 27 minutes to complete. What's more, the drug was very safe at the dose administered, about six milligrams per kilogram of body weight. The takeaway: any competitive athlete in an aerobic sport would crazy not to use it!
So what is this wonder drug? It's good ol' caffeine.
Caffeine is the world's most widely consumed psychoactive substance. Adults in the U.S. imbibe about 200 milligrams of the drug each day on average, mostly through caffeinated beverages like soda, tea, and coffee. It's also probably the most widely used performance enhancing substance. About three in four athletes tested between 2004 and 2015 at national and international sporting competitions had caffeine in their bodies during their events, according to two studies. And for good reason. According to the International Society of Sports Nutrition:
“Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance... Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions."
WIND: caffeine works from what I can tell, if only because it increases mental alertness. Maybe that’s all it does? Dunno.
At 35m caffeine per serving with 3 servings per liter of fluid, that’s 300 calories and 105mg of caffeine in a 1-liter bottle.
While I lose at least 1L/hour of fluid at standard riding pace (more than twice that in hot conditions), the stomach cannot tolerate more than 1L of fluid per hour and/or more than about 240 calories per hour.
My typical fluid consumption for a double century has ranged from as little as 6 liters in ~10 hours to as much as 12 liters of fluid over ~15 hours for a total of ~650 to ~1300mg of caffeine over that time frame.
That alone would lead to bad dehydration (too much fluid lost relative to intake), but the release of water from the utilization of body stores of glycogen release an additional ~2 liters of water (maybe as much as 2.5L) as the glycogen is burned off. Indeed, I’ve had excessive urination for up to 70 miles because of consuming even a single liter of fluid, that is, when fully loaded with glycogen prior.