She was shocked to later find out she was experiencing caffeine withdrawal every single morning. Over time, our bodies become dependent on caffeine and we experience withdrawal when we have gone a long time without it.

Whenever you start your day with a caffeinated drink like coffee you begin to feel more alert. Not because it gives you energy, but because it temporarily hides any tiredness you are naturally feeling.

Unfortunately, this is temporary. By the afternoon your body has broken down some of the caffeine you consumed in your morning coffee, leaving those adenosine receptors empty and available. Since adenosine has built up throughout the day, these open receptors are suddenly bombarded by adenosine molecules causing sleepiness fairly quickly, aka, the afternoon crash.

At this point in the day, you may be ready to wind down, but your brain is not. Since the half-life of caffeine is about 6 hours, its stimulating effects may still be at work well into the evening.

If you drink a cup of caffeinated coffee at 2pm, you have half of that amount in your system at around 8pm.

If you consume caffeine on a daily basis, you likely started with one cup a day and have increased that number of cups over time to combat the afternoon crash and make yourself feel better.

Over time, your caffeine tolerance increases and you need more caffeine to feel the same. This may be due to your body creating more adenosine receptors to compensate for the receptors blocked by caffeine.

Essentially you are fighting against your body. You drink caffeine which blocks adenosine receptors. Your body needs available adenosine receptors to function normally, so it creates more.

Then you feel sleepy, drowsy or other types of awful and drink more caffeine to overcome those feelings. Then your body creates more receptors. The length of time caffeine stays in the body varies from person to person.

Although it blocks adenosine receptors, it does not affect the production of new adenosine molecules. When caffeine wears off, adenosine molecules can bind to their receptors, which can cause sleepiness. People who regularly consume coffee and other caffeinated beverages can develop a tolerance to it.

Since caffeine blocks adenosine receptors, the body produces more adenosine receptors to counteract the effects of frequent caffeine consumption. In one small study , researchers examined the effects of continuous caffeine consumption on the cycling performance of 11 physically active adults.

At the start of the study, the participants had higher heart rates and exerted greater cycling power after drinking caffeine. After 15 days, however, the effects of the caffeine began to decrease. Given these results, it appears that people who regularly consume caffeine may build up a tolerance to its stimulant effects.

However, other research has suggested that continuous exposure to caffeine does not affect how the body absorbs or metabolizes it. Many human and animal studies suggest that compounds inside coffee may improve glucose metabolism and reduce the risk of type 2 diabetes.

However, the adverse effects of caffeine may negate the beneficial effects of drinking coffee. According to a meta-analysis , caffeine can increase blood sugar levels by temporarily reducing insulin sensitivity.

In a small study , researchers observed that consuming mg of caffeine adversely affected glucose metabolism in 10 healthy males with excess weight. These findings suggest that caffeine, not coffee itself, can impact glucose metabolism, which can raise blood sugar levels.

People with high blood sugar may experience headaches , fatigue, trouble concentrating, increased thirst, or frequent urination until their blood sugar levels return to normal.

The sections below discuss a few possible effects of drinking coffee. The authors of a study recommend that people stop drinking coffee at least 6 hours before they plan to fall asleep. Also, according to one study , researchers reported an association between higher caffeine intake and more severe insomnia in middle school students in South Korea.

For example, high doses of caffeine above mg can cause jitteriness and nervousness. In people with panic disorders and depression , high doses of caffeine can trigger anxiety-related symptoms.

There may be temporary increases in heart rate and blood pressure after a person drinks caffeinated coffee. However, current research suggests that mild-to-moderate coffee consumption may protect heart health. In a study involving individuals in Brazil, researchers found evidence to suggest that consuming one to three cups of coffee per day may reduce risk factors for cardiovascular disease in a population.

However, the findings of a study suggest that drinking more than six cups of coffee per day could increase cardiovascular risk. The authors of a review article found evidence to suggest a potential association between increased coffee consumption and a reduced risk of hepatocellular carcinoma.

This is a type of liver cancer. Also, research from found that coffee compounds — including caffeine, trigonelline, and chlorogenic acid — protect against gastrointestinal and liver cancer progression.

However, more research is necessary to confirm the links between drinking coffee and cancer risk. The Dietary Guidelines for Americans — recommend that most adults stick to mg of caffeine per day.

For U. adults, coffee is the most common source of caffeine, followed by tea, soda, energy drinks, and food. So how does caffeine give us a pep in our step, or simply help us combat fatigue after a tough day or sleepless night?

When you consume caffeine, it is absorbed through your gastrointestinal tract into your circulatory system, traveling throughout your body and readily crossing into your brain.

Depending on the individual, blood concentrations peak anywhere from 15 minutes to two hours after consumption. The metabolism of caffeine also varies person to person, taking two to 12 hours to decrease by half.

When blood concentrations peak, you are likely to feel the characteristic effect of caffeine: a boost in energy.

A study published in found that participants who actively made music through singing, keyboard playing, or rhythm tapping felt more energetic than others. In contrast, the researchers noted that listening to music or a story might decrease your energy.

The next time you listen to a song, try singing along to feel more awake. Your body responds to lightness and darkness as signals to be awake and to fall asleep.

Your circadian rhythm —the physical, mental, and behavioral changes that follow a hour cycle—takes those light and dark signals so that your body knows when to rest and when to be awake. Here are a few ways you can use sunlight to regulate your circadian rhythm:.

Aromatherapy involves applying essential oils, such as those from flowers, herbs, or trees, to your skin or inhaling them. A study published in found that a blend of clove bud, frankincense, orange, and thyme helped decrease fatigue in women with post-acute COVID, or long COVID.

Other essential oils that you might try using include:. There are many other ways to get energy without resorting to a cup of coffee if you are trying to cut back on your caffeine intake.

However you decide to get more energy, there are plenty of alternatives to that cup of coffee. For example, eat regularly throughout the day with lean proteins and fiber-rich carbohydrates since you get energy from food.

You can also substitute caffeine with water to avoid dehydration and the fatigue that comes with it. Try relieving stress with exercise or meditation. Chang AM, Aeschbach D, Duffy JF, et al. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.

Proc Natl Acad Sci U S A. Pham HT, Chuang HL, Kuo CP, et al. Electronic device use before bedtime and sleep quality among university students. Healthcare Basel. Ginns P, Kim T, Zervos E. Chewing gum while studying: Effects on alertness and test performance. Appl Cogn Psychol.

Zhang N, Du SM, Zhang JF, et al. Effects of dehydration and rehydration on cognitive performance and mood among male college students in Cangzhou, China: A self-controlled trial. Int J Environ Res Public Health. Water in diet. de Rijk MG, van Eekelen APJ, Kaldenberg E, et al. The association between eating frequency with alertness and gastrointestinal complaints in nurses during the night shift.

J Sleep Res. Academy of Nutrition and Dietetics. Eating to boost energy. Campanelli S, Tort ABL, Lobão-Soares B. Pranayamas and their neurophysiological effects. Int J Yoga. Malhotra V, Javed D, Wakode S, et al. Study of immediate neurological and autonomic changes during kapalbhati pranayama in yoga practitioners.

J Family Med Prim Care. National Heart, Lung, and Blood Institute. Your guide to healthy sleep. Mendelsohn AI. Creatures of habit: The neuroscience of habit and purposeful behavior.

Biol Psychiatry. NIH News in Health. Good sleep for good health. Bergouignan A, Legget KT, De Jong N, et al. Effect of frequent interruptions of prolonged sitting on self-perceived levels of energy, mood, food cravings and cognitive function.

Int J Behav Nutr Phys Act. Office of Disease Prevention and Health Promotion. Get active. Lim JH, Kim H, Jeon C, et al. The effects on mental fatigue and the cognitive function of mechanical massage and binaural beats brain massage provided by massage chairs.

Complement Ther Clin Pract. Yang J, Do A, Mallory MJ, et al. Acupressure: An effective and feasible alternative treatment for anxiety during the COVID pandemic. Glob Adv Health Med. Vitamin D. Sizar O, Khare S, Goyal A, et al. Vitamin D deficiency.

In: StatPearls. StatPearls Publishing; Dzik KP, Kaczor JJ. Mechanisms of vitamin D on skeletal muscle function: Oxidative stress, energy metabolism and anabolic state.

Eur J Appl Physiol. Parker KN, Ragsdale JM. Effects of distress and eustress on changes in fatigue from waking to working. Appl Psychol Health Well Being. Office of Dietary Supplements. Vitamin B12 - consumer. Dutheil F, Danini B, Bagheri R, et al.

Effects of a short daytime nap on the cognitive performance: A systematic review and meta-analysis. American Heart Association. Take a nap: The benefits of napping and how to make it work for you. Lim HA, Watson AL.

Musical tasks and energetic arousal. J Music Ther. National Institute of General Medical Sciences. Circadian rhythms. Reddy S, Reddy V, Sharma S. Physiology, circadian rhythm. National Center for Complementary and Integrative Health. Hawkins J, Hires C, Keenan L, et al.

Aromatherapy blend of thyme, orange, clove bud, and frankincense boosts energy levels in post-COVID female patients: A randomized, double-blinded, placebo controlled clinical trial. Complement Ther Med. Use limited data to select advertising. Create profiles for personalised advertising.

Use profiles to select personalised advertising. Create profiles to personalise content. Use profiles to select personalised content. Measure advertising performance. Measure content performance. Understand audiences through statistics or combinations of data from different sources.

Develop and improve services. Use limited data to select content. Coffee could be associated with a lower risk of death, regardless of other factors, like age, weight status, or alcohol consumption.

Still, more research is needed. Coffee is often used as an ergogenic aid by athletes looking to improve performance and increase energy levels Another study in older adults found that drinking coffee was associated with improved physical performance and faster gait speed, even after the researchers adjusted for factors like age, belly fat, and physical activity levels Additionally, a large review reported that moderate caffeine consumption could slightly improve power output and time-trial completion time.

However, results varied, so the researchers also noted that caffeine may affect people differently Coffee could improve physical performance and endurance when consumed before exercising. However, some studies have turned up mixed results.

Coffee is a popular beverage that researchers have studied extensively for its many health benefits, including its ability to increase energy levels, promote weight management, enhance athletic performance, and protect against chronic disease. Keep in mind that some people may need to limit their intake, including people who are pregnant or breastfeeding, children and adolescents, and people with certain health conditions Still, drinking coffee in moderation — about three to four cups per day — has been associated with several health benefits and is generally considered safe for most adults Try this today: One way to maximize the benefits of your daily cup of joe is to switch up your sweetener.

Instead of using sugar or flavored syrups, opt for a naturally derived low calorie sweetener like stevia, or add a dash of cinnamon for flavor. Our experts continually monitor the health and wellness space, and we update our articles when new information becomes available.

VIEW ALL HISTORY. Coffee is incredibly high in antioxidants. Several studies have shown that people get more antioxidants from coffee than any other food group. Caffeine can have impressive health benefits, but high doses can also lead to unpleasant side effects. Here are 9 side effects of too much caffeine.

Drinking coffee each morning does have several health benefits, but too much can raise your risk of cardiovascular disease. Decaf coffee is coffee that has had almost all of the caffeine removed.

Decaf is loaded with antioxidants and has many health benefits. Bulletproof coffee is a morning coffee drink containing butter and MCT oil.

Here are 3 potential downsides of Bulletproof coffee. Coffee was once considered unhealthy, but new studies have shown coffee to have powerful health benefits.

Here are 7 reasons why coffee is good for…. Some claim that coffee and other caffeinated beverages can interfere with iron absorption.

This article explains how coffee and caffeine affect iron…. An average cup of coffee contains 95 mg of caffeine, but some types contain over mg.

This article lists the caffeine content in different coffee…. Coffee contains caffeine, a stimulant substance that is proven to increase the release of fats from the fat tissues and boost the resting metabolic….

A new study finds that people on the Atlantic Diet were less likely to develop metabolic syndrome, a set of risk factors for diabetes, heart disease…. A Quiz for Teens Are You a Workaholic? How Well Do You Sleep? Health Conditions Discover Plan Connect. Nutrition Evidence Based 9 Unique Benefits of Coffee.

Medically reviewed by Maya Feller, MS, RD, CDN , Nutrition — By Rachael Ajmera, MS, RD — Updated on February 23, Share on Pinterest. Boosts energy levels. May be linked to a lower risk of type 2 diabetes. Could support brain health.

May promote weight management. Linked to a lower risk of depression. Could protect against liver conditions. Supports heart health. Could increase longevity. May enhance athletic performance. The bottom line. Just one thing Try this today: One way to maximize the benefits of your daily cup of joe is to switch up your sweetener.

Was this helpful? How we reviewed this article: History.

Caffeine can block the effects of the hormone adenosine, which is responsible for deep sleep. Caffeine binds to adenosine receptors in the brain, which not only lowers adenosine levels but also increases or decreases other hormones that affect sleep, including dopamine, serotonin, norepinephrine, and GABA.

Caffeine intake later in the day close to bedtime can interfere with good sleep quality. Although developing a caffeine tolerance by taking caffeine regularly over time may lower its disruptive effects, [1] those who have trouble sleeping may consider minimizing caffeine intake later in the day and before going to bed.

In sensitive individuals, caffeine can increase anxiety at doses of mg or more a day about 4 cups of brewed coffee. High amounts of caffeine may cause nervousness and speed up heart rate, symptoms that are also felt during an anxiety attack. Those who have an underlying anxiety or panic disorder are especially at risk of overstimulation when overloading on caffeine.

Caffeine stimulates the heart, increases blood flow, and increases blood pressure temporarily, particularly in people who do not usually consume caffeine. However, strong negative effects of caffeine on blood pressure have not been found in clinical trials, even in people with hypertension, and cohort studies have not found that coffee drinking is associated with a higher risk of hypertension.

Studies also do not show an association of caffeine intake and atrial fibrillation abnormal heart beat , heart disease , or stroke.

It may help to boost energy if one is feeling fatigued from restricting caloric intake, and may reduce appetite temporarily. Caffeine stimulates the sympathetic nervous system, which plays a role in suppressing hunger, enhancing satiety, and increasing the breakdown of fat cells to be used for energy.

Caffeine can cross the placenta, and both mother and fetus metabolize caffeine slowly. A high intake of caffeine by the mother can lead to prolonged high caffeine blood levels in the fetus. Reduced blood flow and oxygen levels may result, increasing the risk of miscarriage and low birth weight.

A review of controlled clinical studies found that caffeine intake, whether low, medium, or high doses, did not appear to increase the risk of infertility. Most studies on liver disease and caffeine have specifically examined coffee intake. Caffeinated coffee intake is associated with a lower risk of liver cancer, fibrosis, and cirrhosis.

Caffeine may prevent the fibrosis scarring of liver tissue by blocking adenosine, which is responsible for the production of collagen that is used to build scar tissue.

Studies have shown that higher coffee consumption is associated with a lower risk of gallstones. Therefore, it is likely that caffeine contributes significantly to this protective effect. The gallbladder is an organ that produces bile to help break down fats; consuming a very high fat diet requires more bile, which can strain the gallbladder and increase the risk of gallstones.

It is believed that caffeine may help to stimulate contractions in the gallbladder and increase the secretion of cholecystokinin, a hormone that speeds the digestion of fats. Animal studies show a protective effect of caffeine from deterioration in the brain. Caffeine has a similar action to the medication theophylline, which is sometimes prescribed to treat asthma.

They both relax the smooth muscles of the lungs and open up bronchial tubes, which can improve breathing. Caffeine stimulates the release of a stress hormone called epinephrine, which causes liver and muscle tissue to release its stored glucose into the bloodstream, temporarily raising blood glucose levels.

However, regular caffeine intake is not associated with an increased risk of diabetes. In fact, cohort studies show that regular coffee intake is associated with a lower risk of type 2 diabetes , though the effect may be from the coffee plant compounds rather than caffeine itself, as decaffeinated coffee shows a similar protective effect.

Caffeine toxicity has been observed with intakes of 1. Consuming grams at one time is believed to be fatal. Caffeine intake up to 10 grams has caused convulsions and vomiting, but recovery is possible in about 6 hours.

Side effects at lower doses of 1 gram include restlessness, irritability, nervousness, vomiting, rapid heart rate, and tremors. Toxicity is generally not seen when drinking caffeinated beverages because a very large amount would need to be taken within a few hours to reach a toxic level 10 gm of caffeine is equal to about cups of brewed coffee.

Dangerous blood levels are more often seen with overuse of caffeine pills or tablets. The contents of this website are for educational purposes and are not intended to offer personal medical advice.

You should seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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Health Information Policy. Media Requests. News Network. Price Transparency. Medical Professionals. Clinical Trials. VIEW ALL HISTORY. Coffee is incredibly high in antioxidants. Several studies have shown that people get more antioxidants from coffee than any other food group.

Caffeine can have impressive health benefits, but high doses can also lead to unpleasant side effects. Here are 9 side effects of too much caffeine. Drinking coffee each morning does have several health benefits, but too much can raise your risk of cardiovascular disease.

Decaf coffee is coffee that has had almost all of the caffeine removed. Decaf is loaded with antioxidants and has many health benefits. Bulletproof coffee is a morning coffee drink containing butter and MCT oil. Here are 3 potential downsides of Bulletproof coffee. Coffee was once considered unhealthy, but new studies have shown coffee to have powerful health benefits.

Here are 7 reasons why coffee is good for…. Some claim that coffee and other caffeinated beverages can interfere with iron absorption. This article explains how coffee and caffeine affect iron….

An average cup of coffee contains 95 mg of caffeine, but some types contain over mg. This article lists the caffeine content in different coffee…. Coffee contains caffeine, a stimulant substance that is proven to increase the release of fats from the fat tissues and boost the resting metabolic….

A new study finds that people on the Atlantic Diet were less likely to develop metabolic syndrome, a set of risk factors for diabetes, heart disease…. A Quiz for Teens Are You a Workaholic?

How Well Do You Sleep? Health Conditions Discover Plan Connect. Nutrition Evidence Based 9 Unique Benefits of Coffee. Medically reviewed by Maya Feller, MS, RD, CDN , Nutrition — By Rachael Ajmera, MS, RD — Updated on February 23, Share on Pinterest. Boosts energy levels.

May be linked to a lower risk of type 2 diabetes. Could support brain health. May promote weight management. Linked to a lower risk of depression. Could protect against liver conditions. Supports heart health. Could increase longevity. May enhance athletic performance. The bottom line.