Drinking water can be a safe, simple and effective way to prevent yourself from passing out.
Within three minutes of drinking a few cups of water (12 mL/kg body weight), the adrenal hormone level noradrenaline in our blood circulation can increase by 60 percent, as you can see in the graph below and at 0:19 in my video The effect of drinking water on adrenal hormones.
When researchers had people drink two cups (500 mL) of water with electrodes on their feet, there was about a 40 percent increase in bursts of fight-or-flight neural activity within 20 minutes, as shown in the graph below and at 0:25 in my video.
If you drink two or three cups (11 mL/kg body weight) of water, blood flow is compressed in your arms and calves, tightening almost half as much as the arteries in your limbs and skin tighten to divert blood to your core as you can see in the graph below and at 0:42 in my video. This is why drinking water can be such a safe, simple and effective way to prevent yourself from fainting, which is known medically as syncope.
faint it is “the sudden brief loss of consciousness caused by reduced cerebral blood flow”, i.e. to the brain. About one in five people experience this at least once, and about one in ten may have repeated episodes. It is the cause of millions of emergency room visits and hospitalizations each year. Although fainting can be caused by heart problems, it is most often caused by prolonged standing (because blood pools in our legs) or strong emotions, which can cause our blood pressure to drop.
About 1 in 25 people has What’s called blood-injection-injury phobia, where sticking a needle, for example, can make you pass out. More than 150,000 people experience fainting or near-fainting spells each year when giving blood. To prevent your pain, try drinking two cups of water (500 mL) five minutes before you get stuck with the needle. The secret is not in boosting your total blood volume. If you drink two cups of water or even a full liter (500 to 1,000 mL), your blood volume doesn’t change more than 1 or 2 percent. Rather, it is due to the shift in blood distribution towards your center, is caused from noradrenaline-induced peripheral artery constriction, as you can see in the graph below and at 1:56 in my video.
Drinking water stimulates as much noradrenaline release as drinking two cups of coffee or smoking two cigarettes without filtering. If the simple act of drinking water triggers such a profound fight-or-flight response, why doesn’t it cause our heart to pound and our blood pressure to shoot through the roof? It’s like the diving reflex I talked about in my previous video. When we drink water, our body simultaneously sends signals to our heart to slow it down, to “stop your beating heart.” You can try this at home: Measure your heart rate before and after drinking two cups (500 mL) of water. Within ten minutes, your heart rate should slow by about four beats per minute. At 15 minutes, you should have dropped six or seven beats, as you can see in the chart below and at 2:42 in my video.
One of the ways scientists figured this out was by studying heart transplant patients. When you move a heart from one person to another, you have to cut all the connected nerves. Surprisingly, some of the nerves grow back. However, if you give heart transplant patients two glasses of water, their blood pressure rises by up to 29 degrees. The body is unable to adequately suppress the effect of this noradrenaline burst. Some people have a condition known as autonomic failure, in which the blood pressure-regulating nerves don’t work properly and their pressure can jump dangerously by more than 100 degrees after drinking about two cups (480 mL) of water. That’s how powerful the simple act of drinking water can be. The only reason it doesn’t happen to all of us is that we have an even stronger reaction to keep our hearts in check. (This reminds me of the woman who had stroke after the ice bucket challenge due to insufficient diving reflex to limit all this extra noradrenaline release.)
This remarkable water effect box it is useful for people who suffer from milder forms of autonomic failure, such as postural hypotension, which is when people feel dizzy after suddenly standing up. Drinking some water before getting out of bed in the morning can be a big help. But what about that metabolic boost? With so much noradrenaline being released and your adrenal hormones in overdrive, can drinking a few glasses of water make you burn more body fat? Could tap water be a safe form of ephedra, giving us all the weight loss but with a nice slowing of our heart rate instead? The researchers decided to put is in testing, which we’ll explore next.
If you missed the previous video, check it out How to get the benefits of Ephedra for weight loss without the risks.
Stay tuned for What is the safest metabolism booster? and Friday Favorites: Optimizing Water Intake for Weight Loss.
What kind of water is best? Find out at IIt is best to drink tap, filtered or bottled water?.
