How does caffeine affect weight loss and physical activity? Book Excerpt of the Week

How does caffeine affect weight loss and physical activity? Caffeine encourages several small metabolic changes, and all these changes encourage the use of fat for fuel instead of glucose. But how does caffeine trigger all these small changes? The answer has to do with adenosine’s throne.

Okay, so let’s say that adenosine has a throne that only adenosine can fit into. When adenosine sits on its throne, it can send signals to make us sleepy. Fortunately for us, caffeine is similar enough in size to fit adenosine’s special throne. When that happens, caffeine blocks adenosine, preventing those sleepy signals from being sent. But adenosine has more than one throne. In fact, we have adenosine receptors all over the body. Interacting with all those adenosine receptors is how caffeine is able to trigger these small metabolic changes that encourage fat-burning over glucose-burning for fuel.

This fat-burning boost sounds awesome! But there is one more thing about caffeine and physical activity we need to consider: the effect on blood pressure. This brings us to the Excerpt of the Week:

Both caffeine and exercise raise heart rate and blood pressure, so combining them can have a scary, additive effect. In general, 200 mg caffeine per “sitting” or occasion is considered safe by multiple sources, including the EFSA. But if you’ve never consumed a pre-workout supplement or other source of caffeine before a workout before, start small.

We’ll talk MUCH MORE about caffeine and fat metabolism/weight-loss when we get to the GREEN TEA section of this book. For now, let me just say that no one should expect an energy drink to be a safe or effective weight-loss method. If an energy drink helps you make it to your workout, that’s a different story. Remember – caffeine is not a miracle weight loss tool!

When is the last time you saw a story or post about someone who lost weight because they started drinking Product X?  Unless it comes with a diet and exercise regime, you can ignore that story.

An energy drink may give you wings, but it will not make you lighter all by itself.

You can get your copy of “Are You a Monster or a Rock Star-A Guide to Energy Drinks: How They Work, Why They Work, How to Use Them Safely” on Amazon and wherever books are sold.

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Stay tuned for next week’s book excerpt, as we continue to move page-by-page through the Energy Drink Guide.

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How Caffeine Works

Caffeine is a compound naturally found in cocoa beans, kola nuts, tea leaves and other plants like guarana. Caffeine is a stimulant that affects your whole body. Caffeine is a vasodilator, meaning it makes your blood vessels slightly larger in diameter. However, caffeine constricts the blood vessels in your brain. This effect is why caffeine can be found in certain pain or headache medications. It is easier to stem the tide of pain to your brain than to ease the pain once the full force has hit.

How would you like to get paid for preventing someone from doing their own job? Football quarterback-tackling metaphors aside, caffeine works by keeping adenosine from doing its job.

Adenosine is a neurotransmitter, a chemical which affects the way nerves function. Adenosine is a by-product of cellular metabolism like sweat is a by-product of hard physical activity. Just as sweat is there to cool us down, adenosine is there to slow us down. The longer a person is awake and active, the more adenosine accumulates until eventually, they feel it is time to sleep. This is the body’s way of self-regulating activity.

Caffeine works by blocking adenosine from reaching its receptors. If adenosine were a key, and its receptor was a lock, then caffeine is a key that is similar enough to adenosine to fit into the lock, but not similar enough to open or close the lock. As long as caffeine is sitting in those adenosine receptors, adenosine cannot get in and cannot signal fatigue.

That said, caffeine is not always able to block out adenosine. If you’ve been awake for more than 16 hours, your brain has done enough activity to generate a whole army of adenosine. At that point, no amount of caffeine is going to be effective enough to make you truly feel alert and awake.

In a situation called “Competitive Inhibition”, caffeine inhibits adenosine because these two molecules are similar enough in shape to both fit into the adenosine receptor. HOWEVER, in this type of inhibition, the odds of caffeine getting to that receptor before adenosine drop (like your eyelids) when caffeine gets outnumbered.

When you are pushing yourself to stay up too long (*and “too long” will vary by individual, but chances are you’ll know that limit when you get to it*), PLEASE don’t rely on an energy drink to help you. At a certain point, your only salvation is either a nap lasting 20 minutes or a full 6 hours of sleep. You have to pick one or the other, because often times naps longer than 20 minutes can be counter-productive due to REM cycle science that I can’t really explain that well here.