"I would just like to declare that this is my educated speculation, please feel free to ask me any questions or debate with me.
There have been several reports in the news lately of healthy athletes dropping dead due to a sudden heart attack. A couple of these reports, including the most recent Boston Marathon death, have shown athletes with caffeine in their systems. Some have claimed the athletes are taking a supplement which contains caffeine and the amino acid L-arginine. Caffeine alone should be used with caution in endurance training. Since caffeine is a diuretic, it can make you more susceptible to dehydration or in some cases, hyponatremic encephalopathy: a swelling of the brain due to a sodium deficiency. Most cases of hyponatremic encephalopathy are attributed to drinking too much water with the intention of rehydrating, but the diuretic effects of caffeine will lower that threshold of what is considered drinking “too much water”.
If you are already dehydrated, your blood pressure will drop quite low and if you add arginine into the mix your blood pressure will drop even lower. When your blood pressure drops too low and the hypotensive triggers are gone, eventually you will get rebound hypertension. This effect is seen in surgery when a patient is purposely put into hypotension with medications that dilate the blood vessels (the same effect arginine has). Once this drug wears off, with the body’s intention of bringing the blood pressure back to homeostasis, the blood pressure elevates higher than normal (rebound hypertension). I suspect that this effect is why these athletes usually die once they are resting or right after the event.
Think about how hard your heart will have to work if you dilate all of your blood vessels and take caffeine. To start, you take arginine which will lower your peripheral resistance and help blood flow easier through the body. Now your blood pressure is lower because it doesn’t have to work as hard to pump to the rest of the body since there is less resistance. Now you start physically exerting yourself, increasing the demand for oxygen and nutrients to your tissues (muscles, skin, etc.). Your heart works harder to pump blood to these tissues but because the path is wider, it takes more blood to transport the oxygen and nutrients. Now your heart is trying to pump more blood than usual to these tissues. This scenario is dangerous enough and now we’ll factor caffeine into it. Caffeine simulates stress, so it puts us into the stimulated fight or flight mode. This increases the heart rate even more, first elevates and then eventually decreases blood pressure even more via the diuretic effect depleting sodium. This increases the demand of the tissues that the heart needs to pump oxygen and nutrients to. On top of all of this, our lungs have to compensate and oxygenate this increase in demand. These are sure determinants to lead to heart failure.
There are several other factors that can make this situation even worse:
- Caffeine factors (how each individual metabolizes caffeine, route of caffeine administration, other ingredients, etc.)
- Underlying heart conditions (most go undiagnosed until a cardiac mishap takes place)
- How hard the athlete pushes themselves
- Duration of the athletic event
- Hydration status
- The physical condition the athlete is in
- Dose and administration of arginine
- How well the liver and kidneys are functioning
- Several other factors that need to be considered
Regularly your blood vessels are like a one-lane highway. Traffic will congest the one-lane highway and the main street that cars are entering it from. You take arginine to vasodilate your blood vessels into a three-lane highway. Now the cars have a calm steady flow and the pressure is taken off of the main street. Now picture all of these cars as ambulances trying to get to accidents at all the different highway exits. It’s a blizzard out there and as time goes by there’s more and more demand for these ambulances. The hospitals are sending out as many ambulances as they can but they can’t keep up with the demand because the accidents are so far apart. Eventually the hospitals run out of ambulances and now that the arginine has worn off the highway is back down to one-lane highway and all of the ambulances start crashing into each other.
- Rely more on proper hydration rather than on “performance-enhanging supplements". You can drink all the coconut water or sports drinks you want but if you take a diuretic you could be negating their effects.
- See a licensed health professional about proper training.
To make a long story short:
- Dehydration, diuretics (caffeine) and arginine all reduce your blood pressure. When all three of these are combined, it can be fatal, especially once the body tries to maintain homeostasis and rebounds into hypertension."