how much caffeine affects sleep?
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The most obvious effect of the stimulant is that it can make it hard for you to fall asleep. One study also found that caffeine can delay the timing of your body clock. These effects will reduce your total sleep time. Caffeine also can reduce the amount of deep sleep that you enjoy.
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The lethal dose of caffeine for most people, says Temple, is about 10 grams, although this varies from person to person. A cup of coffee has around 100 to 200 milligrams of caffeine. An energy drink contains anywhere from 50 to 300 mg of caffeine.
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Potential risks include increase in blood pressure and heart rate, dehydration, irregular heartbeat, heart failure, anxiety and insomnia. The risk is especially high for children and adolescents. A single 8-ounce energy drink can have as much as 250 milligrams of caffeine, according to the FDA.
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A normal dose of caffeine is about 50 mg to 200 mg. Caffeine works best when you take it on an intermittent, off-and-on basis. Higher doses can have much more potent effects. A dose of 500 mg or 600 mg of caffeine can affect you much like a low dose of an amphetamine.
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While safe doses of caffeine vary by individual, current research recommends limiting caffeine to 400 mg per day or less in healthy adults ( 28 ). As one small 8.4-ounce (260-ml) can of Red Bull provides 75 mg of caffeine, drinking more than 5 cans per day could increase your risk of caffeine overdose ( 2 ).
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The bottom line. Coffee itself won't instantly make you feel tired, but the caffeine it contains may actually lead to fatigue after regularly drinking it over time.
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Levels of caffeine peak in the blood within about 15–45 minutes of consumption. They are then quickly metabolized by the liver. Most people notice the strongest effects during this time, and many report feeling jittery, needing to urinate, and having sudden bursts of energy.
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According to research, you should avoid consuming caffeine from around 2pm, or at least seven hours before bed, as it can otherwise negatively affect your sleep.
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What happens when they mix? Caffeine is a stimulant that can make you feel energetic and alert. Alcohol, on the other hand, is a depressant that can make you feel sleepy or less alert than usual.
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The effects from caffeine reach peak levels within 30 to 60 minutes of consumption. This is the time you're most likely to experience the “jittery” effects of caffeine. You might also urinate more due to the liquid volume being ingested and caffeine's mild diuretic effect.
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The effects from caffeine reach peak levels within 30 to 60 minutes of consumption. This is the time you're most likely to experience the “jittery” effects of caffeine.
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Up to 400 mg of caffeine per day is generally safe. Still, drinking more than four, 8-ounce (240-ml) servings of energy drinks per day — or two, 16-ounce (480-ml) cans of Monster — may cause negative effects due to excess caffeine, such as headache or insomnia ( 9 , 10 ).
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Specifically, too much caffeine can cause nervousness, trouble sleeping, nausea, vomiting, rapid heartbeats, and higher blood pressure. Many makers of energy shots say children and those who are pregnant, nursing, or sensitive to caffeine should avoid the beverages. 5-Hour Energy advises no more than two bottles a day.
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Coffee, cola and other caffeine based drinks act as stimulants. Studies have found that the effects of a cup of coffee or a glass of cola are noticeable after just 10 minutes, but the peak caffeine concentration in the blood occurs after 45 minutes.
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Regular use of caffeine can cause a lack of sleep resulting in fatigue and anxiety. Common complaints with caffeine use is nausea, nervousness, dizziness, and irritability. Studies also have been done on coffee and it's association with stomach pain.
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For Children While an older study found that high doses of caffeine (600 milligrams) every day helped control hyperactivity symptoms in children, there were many side effects. Kids with ADHD generally have more sleep problems and have trouble staying alert during the day.
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Data synthesis: Caffeine appears to affect blood pressure through adenosine receptor inhibition and an increased release of select neurotransmitters. Caffeine levels peak 30-120 minutes after oral intake and caffeine's half-life is 3-6 hours.