Coffee is the nectar of the gods.
Partially because the aroma of it is the planets best aphrodisiac and it tastes like a million angles are dancing on sunshine, but most importantly it contains caffeine.
Ok, this is probably a bit of hyperbole but coffee is one of the most popular beverages consumed in the world.
In fact, the average American drinks 3.1 cups of coffee per day and we spend approximately $40 billion on coffee each year1. That number is mind-boggling.
Caffeine has garnered a lot of attention in both the fitness world and in the research world due to a lot of the performance and health properties it can convey. Sadly, as with most health claims, many of the things you hear are like unicorns, they aren’t real.
Now since caffeine is one of the most consumed “drugs” on the planet I think we ought to set the record straight and clear up a few of the myths surrounding caffeine.
1. Caffeine dehydrates you
People think that because coffee makes you pee it dehydrates you. I never really understood that logic, it is missing a lot of steps and doesn’t really make any sense when you think about it. For example, drinking water makes you pee but drinking water is how you hydrate.
The body’s fluid balance system is a lot more complicated than that. Honestly, sometimes journalists’ logic baffles me at times. This is where science is important. We can actually ask and answer the question of, “Does caffeine dehydrate you”?
Fortunately for us, several studies have looked at whether caffeine consumption actually dehydrates you. For example, one studied looked at a dose response of caffeine and diuresis (making more urine) and found that daily intakes of caffeine at 3 and 6 mg per kg per day over a span of 11 days does not have a real effect on fluid balance and hydrations status2.
Now that is great and all when considering the study was conducted with pure caffeine, but what about caffeinated beverages and all the other things that go with them? I am glad you asked. Here is a study that showed that black tea also doesn’t do squat as a diuretic and hydrates you just as well as water3.
2. Caffeine is a good fat burner
Caffeine is marketed as a fat burner pretty heavily. The thing about it is that it can be a fat burner. . . but it likely doesn’t work the way you think it does.
The old version of caffeine being a fat burner goes something like this: caffeine causes fat cells to release fatty acids which is then burned for energy. This is kind of true but not really. The data is a little more complex than that.
When you really get down to the nitty gritty, it looks like caffeine increases lipid mobilization by a significant amount but most of that fat isn’t actually burned, about 75% of it is actually recycled, meaning it’s “released” from fat cells and then stored again without being used4.
So caffeine probably won’t directly increase fat loss but it may increase your training capacity, making increased fat-loss a byproduct.
In addition to the fact that most of the “mobilized” fat is simply recycled, caffeine loses its efficacy over time. Much like alcohol or drugs, your body habituates to caffeine and eventually it loses its ability to be stimulated by caffeine. At some point it becomes a “return to normal function” supplement.
If you take a second to think about this you realize how true it is. Think about the first time you had a cup of coffee in the morning and how alert and ready to go you felt. Now fast forward 15 years and think about how you feel like one of those zombies in The Walking Dead until that first cup of coffee kicks in and you feel a little more human.
If you abuse coffee/caffeine as much as I do it might take the whole pot to get you back to normal. . . I should probably take a caffeine break sometime soon.
3. Caffeine is good for performance
People often tout caffeine as the ultimate performance enhancer. This is true to some extent. It is the most effective, legal, ergogenic aid we have on the market, For example, people who are not habituated to caffeine can see increases in strength and power from pre-exercise caffeine supplementation.
Sadly, there is a very large “habituation” effect and caffeine loses its efficacy overtime. In fact, if you want to really maximize your caffeine you should cycle on and off it regularly. This is part of the reason you only get that “first time I took pre-workout feeling” once in your lifetime.
The other reason caffeine may not help your performance is the type of exercise you engage in. Caffeine is a known stimulate than can increase heart rate. In certain cases an elevated heart rate is actually a good way to ruin your performance.
In “metcon” style workouts where your goal is to sustain a relatively high workload for an extended period of time a higher resting rate will actually decrease your time to fatigue, which is the opposite effect of what you want.
The Wrap Up
Let me wrap this thing up in short, snappy sentences. Caffeine is awesome, coffee is my favorite source. It doesn’t dehydrate you. It isn’t the key to getting shredded.
It can help power production and fatigue in some situations but can hurt you during metcon style workouts. Cycling on and off is probably the best idea if you want to use caffeine to augment your performance.
- Coffee by the numbers
- Fluid, electrolyte, and renal indices of hydration during 11 days of controlled caffeine consumption.
- Black tea is not significantly different from water in the maintenance of normal hydration in human subjects: results from a randomised controlled trial.
- Metabolic effects of caffeine in humans: lipid oxidation or futile cycling?