Why does caffeine tire me? Explain the experts

If you rely on your morning coffee to energize yourself during the day, feeling tired after a daily dose of caffeine is probably the last thing you would expect. But, unfortunately, that can happen (sorry, coffee lovers) – hence why some people ask, “Why does caffeine tire me?” It turns out that behind the seemingly contradictory side effects, there are several reasons that, once you learn them, can help you prevent them.

Caffeine is actually a stimulant, so it boosts energy levels and increases alertness by hitting the central nervous system at high speed, signaling your brain to feel awake and awake – hence the confusion when the opposite happens. You usually get it with coffee, but various types of tea and chocolate are other natural sources of caffeine that you can consume.

But there are a number of reasons why your caffeine hit can go bad, says Lindsay Kluge, LDN, a clinical herbalist and licensed nutritionist at the herbal tea company Pukka. From the way you consume caffeine to your stress levels, experts explain the reasons why caffeine tires you and help you pinpoint why your beers aren’t having the desired effect.

1. Blocks adenosine

You have a chemical in your body called adenosine that helps regulate circadian rhythms, Kluge says. During the day, adenosine levels rise to keep you awake, and when you sleep they fall. Caffeine makes you feel awake by temporarily blocking adenosine receptors in your brain to keep those levels high, Kluge says. But if you consume excess caffeine (which studies show is just over 400 milligrams a day), you can collapse as caffeine depletes and adenosine levels change.

“Once the effects of caffeine go away, those adenosine receptors are now open and filled with all of our accumulated adenosine, which slows down brain molecules to help us sleep,” she tells Davna. “So we can feel extra sleepy after we metabolize that stroke of caffeine.”

2. Added sugars draw energy

Sometimes you don’t get tired of caffeine, but the sugar in the caffeinated beverage you mix. The added sugars in your coffee can produce a jump in insulin levels, which lowers blood sugar and can make you feel tired, says Kent Yoshimura, co-founder and CEO of the Neuro Supplements brand. His solution? Try lowering your sugar or balancing your sweet drink with protein-rich snacks such as nuts or eggs, which studies show can help regulate blood sugar levels.

3. Increases the level of stress hormones

Caffeine can increase your levels of a stress hormone called cortisol, Yoshimura says. Excess cortisol can also have its own side effects, including dizziness, sleep problems and – you guessed it – fatigue. And that can further raise cortisol levels, which may already be high due to other stressors, which can add to your feeling of lethargy.

How to handle

The most effective method to avoid caffeine-related accidents? Everything is in balance, says Yoshimura. “The best way to combat caffeine fatigue is to use it responsibly,” says Bustle.

If you often feel tired after consuming caffeine, Kluge recommends eliminating it completely. But if it’s not on the charts, minimizing intake can help you maintain a good energy level throughout the day. He suggests weaning off one cup of coffee in the morning (that’s about 95 milligrams of caffeine on average), replacing coffee with lower or no caffeinated alternatives like tea or chicory root coffee, and avoiding caffeine that starts about six hours before bed. .

Studies with reference:

Hou, Y. (2018). Randomized controlled trial comparing the effect of peanuts and almonds on cardio-metabolic and inflammatory parameters in patients with type 2 diabetes mellitus Nutrients, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6267433/

Lazarus, M. (2019). Housing and sleep needs: inseparable effects of adenosine A1 and A2A Receptors. Boundaries in Neuroscience, https://www.frontiersin.org/articles/10.3389/fnins.2019.00740/full

Lovallo, W. (2005). Stimulation of caffeine by cortisol secretion during waking hours in relation to the level of caffeine intake. Psychosomatic Medicine, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2257922/

Mitchell, D. (2014). Drinking Caffeine Intake in American Food Chemical Toxicology, https://www.sciencedirect.com/science/article/pii/S0278691513007175?via%3Dihub

Nehlig, A. (1992). Caffeine and the central nervous system: mechanisms of action, biochemical, metabolic and psychostimulant effects. Brain research reviews, https://pubmed.ncbi.nlm.nih.gov/1356551/

Porkka-Heiskanen, T. (1999). Adenosine in sleep and wakefulness. Annals of Internal Medicine, https://pubmed.ncbi.nlm.nih.gov/10344585/

Ribeiro, J. (2010). Caffeine and adenosine. Journal of Alzheimer’s Disease, https://pubmed.ncbi.nlm.nih.gov/20164566/

Wikoff, D. (2017). Systematic review of possible harmful effects of caffeine consumption in healthy adults, pregnant women, adolescents and children. Food and Chemical Toxicology, https://pubmed.ncbi.nlm.nih.gov/28438661/


Lindsay Kluge, MS, CNS, LDN, clinical herbalist and licensed nutritionist at Pukka Herbal Tea Company

Kent Yoshimura, co-founder and CEO of the Neuro accessories brand