Exercise versus caffeine: Which is your best ally to fight fatigue?

Chronic lack of sleep makes it hard to focus on a task. As if this didn’t make complete logical sense, multiple research studies have shown that sleep deprivation has about the same effect on our cognition and coordination as a few alcoholic beverages.

What do you do when you need to concentrate, but you’re tired?

Many of us reach for a cup of coffee, or a soda. Mountains of solid research have shown us that caffeine (in doses ranging between 30 and 300 milligrams) improves attention, alertness, reaction time, and mood, especially when we’re tired. An average cup of brewed coffee contains between 80 and 100 milligrams of caffeine; a soda, between 30 and 60.

But exercise works too. This is also well-studied. Even a short bout of any cardiovascular exercise wakes us up, speeds mental processes, and enhances memory storage and retrieval, regardless of our fitness or fatigue levels.

So, when it’s late afternoon and I’m struggling with charting or finishing one of these pieces, what should I do: exercise a bit, or go for coffee?

One recent (and very small) study compared these two wake-up methods. This well-conducted study used healthy but chronically sleep-deprived volunteers to compare three interventions: caffeine, stair-climbing, and placebo. They found that just 10 minutes of stair-climbing boosted self-reported levels of energy far more than a moderate dose of caffeine (50 mg). However, this was a very small study — only 18 out of 90 healthy, college-aged women met all the criteria and were willing to participate.

Digging deeper: Exercise offers more long-term benefits

While the findings make a whole lot of sense, I went to the existing piles of literature for more information.

Interestingly, another study looked at the effects of either exercise alone or exercise plus caffeine on cognitive tasks, and found that (perhaps predictably) exercise plus caffeine had the greater benefit.

Caffeine (in the form of coffee) has been well-studied, and regular intake is associated with lower risk of type 2 diabetes, high blood pressure, and obesity, but may increase cholesterol. It may be protective against certain types of dementia and cancer, but has been associated with bone loss and rheumatoid arthritis. Basically, there are many benefits, but there seem to be some risks as well.

But there are multiple studies suggesting that exercise has multiple long-lasting positive effects on physical fitness and function, cognition, mood, and behavior in just about all populations studied, in all ages, fitness levels, and regardless of baseline cognitive function. Some of the greatest benefits have been seen in older patients, as well as patients at risk for or diagnosed with dementia.

The take-home message? Caffeine can provide a boost in alertness and energy levels that may help you to think faster and better, for a while. But even a short burst of exercise can do the same, maybe more, and for longer. In addition, while caffeine is associated with both good and bad health outcomes, exercise is good for everything.


Neurocognitive consequences of sleep deprivation. Seminars in Neurology, 2005.

Fatigue, alcohol and performance impairment. Nature, 1997.

Quantifying the performance impairment associated with fatigue. Journal of Sleep Research, 1999.

Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational and Environmental Medicine, 2000.

Fatigue-related impairment in the speed, accuracy and variability of psychomotor performance: comparison with blood alcohol levels. Journal of Sleep Research, 2005.

A review of caffeine’s effects on cognitive, physical and occupational performance. Neuroscience & Biobehavioral Reviews, December 2016.

Diet, Brain, Behavior: Practical Implications, CRC Press, 2011.

The effects of low doses of caffeine on human performance and mood. Psychopharmacology, 1987.

Is caffeine a cognitive enhancer? Journal of Alzheimer’s Disease, 2010.

The effect of exercise-induced arousal on cognitive task performance: a meta-regression analysis. Brain Research, 2010.

The effect of a single bout of exercise on energy and fatigue states: a systematic review and meta-analysis. Fatigue: Biomedicine, Health & Behavior, 2013.

Exercise and caffeine improve sustained attention following fatigue independent of fitness status. Fatigue: Biomedicine, Health & Behavior, 2015.

Effects of habitual coffee consumption on cardiometabolic disease, cardiovascular health, and all-cause mortality. Journal of the American College of Cardiology, September 2013.

Habitual coffee consumption and risk of cognitive decline/dementia: A systematic review and meta-analysis of prospective cohort studies. Nutrition, December 2015.

Coffee and autoimmunity: More than a mere hot beverage! Autoimmunity Reviews, May 2017.

Cognitive Benefits of Exercise Intervention. La Clinica Terapeutica, Nov-Dec. 2016.

Role of exercise on the brain. Journal of Exercise Rehabilitation, October 2016.

Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. British Journal of Sports Medicine. 2017.

The effects of exercise training on elderly persons with cognitive impairment and dementia: A meta-analysis. Archives of Physical Medicine and Rehabilitation. October 2004.

Fitness effects on the cognitive function of older adults: a meta-analytic study. Psychological Science, 2003.

Effect of physical activity on cognitive function in older adults at risk for Alzheimer disease: a randomized trial. JAMA, 2008.


  1. Jim Mast

    Have you done any studies on Probiotics, their effectiveness, and which ones should be used with Antibiotics for GI problems? There are many on the market and very little guidence about which ones to use and what they should be used for.

    • Monique Tello, MD, MPH
      Monique Tello, MD, MPH

      This is a hot topic, and certainly a post should be dedicated to reviewing the research on the relationship between our intestinal flora and our health.

  2. Samiulla Bandarkar

    I didn’t know coffee had such a load of benefits!

  3. Birdnscrap

    How does a short nap compare to caffeine or exercise?

    • Monique Tello, MD, MPH
      Monique Tello, MD, MPH

      I did not see any head-to-head studies comparing the three. And, the existing research on naps or comparing caffeine and naps is a bit dated. A 2009 review article shows that generally, napping can improve cognitive performance in varius domains, but more research is needed (J Sleep Res 2009 Jun;18(2):272-81. doi:10.1111/j.1365-2869.2008.00718.x. Benefits of napping in healthy adults: impact of nap length, time of day, age, and experience with napping. Milner CE1, Cote KA.). A 2008 study compared caffeine to naps and found that naps were superior for short-term recall (Behav Brain Res. 2008 Nov 3;193(1):79-86. doi: 10.1016/j.bbr.2008.04.028. Epub 2008 May 8. Comparing the benefits of caffeine, naps and placebo on verbal, motor and perceptual memory. Mednick SC1, Cai DJ, Kanady J, Drummond SP.)

  4. Robert A. Fairey, 89

    I’m just a lawyer and can cite no controlled studies, but I believe the caffeine plus exercise scheme has the greater benefit, with emphasis on exercise and limiting coffee to 2 cups a day. Maybe it’s a de gustibus non disputandum thing. (Don’t like the Latin? Well it’s something you docs like to burden the rest of us with. How’s that for ending a sentence with a preposition?)

  5. dr.jfolli

    Well, I hope Roo Bookaroo won’t fall asleep as soon as he sees my comment. :)) Anyway, as a MD myself, and a former rugby player, I’ve always wondered about why the heck caffeine is always presented in SUCH a positive light. Is it the mark of a powerful coffee lobby? Are there a lot of vested interests thrown in? I don’t know, and I hope not, but like all things unnatural to man (tobacco, alcohol), coffee is bad for your health, period. How does it even compare to exercise? This is pure madness. Like Emmanuel Legeard, Ph.D., who is one of the best Olympic trainer in the World puts it in one of his well-informed articles, it’s even detrimental to athletic performance.

    “regular intake is associated with lower risk of type 2 diabetes, high blood pressure, and obesity, is protective against certain types of dementia and cancer…” It sounds like a miraculous panacea, which it is not.

    Exercise better than coffee? Apples and oranges! Well, rather apples and garbage, geez!

    • Monique Tello, MD, MPH
      Monique Tello, MD, MPH

      Please check the references, all of the resources were peer-reviewed research articles in Pubmed. Most caffeine studies appear to be grant-funded, rather than industry-funded. This may be because there are such a massive variety of caffeine-rich sources, ranging from tea to coffee to soda to supplements, no one industry can benefit. This may also be why there is a relative dearth of recent research: no has a financial stake.

  6. Roo Bookaroo

    Boring comment by Will Roemermann. Making my irresistibly yawn.
    I need to do 10′ of my morning squat/deadlift/pushup/shoulder press routine to eliminate the torpor generated by this comment.

    • Roo Bookaroo

      “Making me irresistibly yawn”, of course.
      It’s reading the previous comment that got my attention to waver. As soon as I reached shoulder press, I noticed my mistake. Thank god for my fitness routine which keeps my writing in impeccable style.

  7. Will Roemermann

    I find the best way to wake up is to stop reading these little ditties from Harvard. Although their research is most likely impeccable, the very nature of their journalists promote boredom and tiredness in return.
    My personal solution is to strive for 7 – 9 hours of good sleep in a comfortable bed with proper head support (pillows) to prevent any nighttime discomforts that develop into morning aches.

    • Monique Tello, MD, MPH
      Monique Tello, MD, MPH

      Yes, I have found that bedtime is not the optimal time of day for perusing the peer-reviewed research literature, for exactly your reasons stated above.

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