Written by: Adam Eckart, Executive Contributor
Executive Contributors at Brainz Magazine are handpicked and invited to contribute because of their knowledge and valuable insight within their area of expertise.
In the golden age of the internet and social media, there’s no shortage of online courses and how-to videos on the topic of boosting productivity. Although the strategies promoted by internet experts can certainly help entrepreneurs and business owners better manage their time or squeeze out more sales, the ability to implement, troubleshoot, and execute these strategies is largely dependent on robust cognitive faculties. Cognitive performance improvement is another mammoth industry for which there are innumerable options ranging from supplementation to transcranial magnetic stimulation.
Most of these methods, like everything else, are not one-size-fits-all and often require ongoing trial and error before results become reliable, if at all. For example, it seems that every year a new “smart drug” supplement comes to market with claims of improved recall memory, work capacity, and focus. That leaves many wondering, “Which one is right for me?”, “ Should I try that one instead?”, “Maybe that one will work better!” This is by no means a criticism of cognitive “biohacking” products. Methods such as fasting or supplementation could be very important components of a wellness routine. The reality, however, is that individuals, especially entrepreneurs, have only so much time and bandwidth to research quality sources, titrate doses, and wade through the deluge of formulations. Once you go down the rabbit hole, you could end up with yet another productivity bottleneck. This may prompt individuals to seek out “more effective” pharmaceutical drugs for which there may not be a legitimate need such as in the case of Adderall for Attention Deficit Hyperactivity Disorder (ADHD). Doing so could result in serious ramifications including addiction and life-threatening conditions.
Exercise: The Original Cognitive Performance Enhancer
Exercise, on the other hand, is a safe, powerful, and reliable method for improving neuroplasticity which sets the limits on cognitive performance. Neuroplasticity refers to the brain’s adaptive capacity for learning, memory, and task-related efficiency. Scientists measure neuroplasticity by testing subjects’ ability to discriminate between important and unimportant stimuli. Neuroplasticity declines with age and disease, but exercise can slow or reverse the effects of aging on cognitive performance. Scientists propose that the relation of exercise and cognitive performance is an evolutionary adaptation that improved our ancestors’ chances of survival. Early nomadic humans trekked and ran long distances to hunt and acquire resources while navigating complex and ever-changing environments. Humans with high levels of physical endurance and above-average cognitive abilities were more likely to survive and reproduce.
Exercise has been shown to enhance levels of neural growth factors such as brain-derived neurotrophic factor (BDNF), a key molecule involved in neuroplasticity related to memory and learning that appears to be linked to age-related cognitive decline (Mattson, 2012; Miranda, Morici, Zanoni, & Bekinschtein, 2019). BDNF increases the strength and speed of electrical impulses as well as increasing the number and size of nerve cells in the brain. Exercise-induced increases in BDNF are mediated by lactate, a by-product produced from the breakdown of muscle glycogen (a stored energy source typically derived from dietary carbohydrates). Lactate serves as an additional energy source for muscles when demand for energy is high and also serves as a neuronal energy source during exercise and rest. The availability of lactate in the brain is important for long-term memory by enhancing levels of several different neural growth factors. Just one bout of exercise above the lactate threshold (the point at which your muscles begin to burn) can improve lactate uptake by neurons in the brain (Taubert, Villringer, & Lehmann, 2015).
BDNF appears to play a role in blood glucose utilization and insulin sensitivity. In mice studies, reduced BDNF levels were associated with increased food consumption and onset of obesity and diabetes (Duan et al., 2003). In a recent human study, obese individuals had imparied neuroplasticity compared to healthy-weight controls when exposed to transcranial magnetic stimulation (University of South Australia, 2020). Interestingly, intermittent fasting (prolonged periods of food abstinence) has a similar adaptive effect on the cardiovascular system compared to endurance exercise. Scientists believe these adaptive similarities implicate BDNF as a mediator of cardiovascular benefits when exposed to various stressors (Mattson, 2012). Endurance exercise is a great alternative to intermittent fasting which has been widely recommended for cognitive performance improvement.
In addition to the effects of exercise on neural growth factors, exercise immediately promotes blood flow to the brain and increases adrenaline and dopamine – powerful neurotransmitters involved in learning, memory, and bodily movement. Exercise also counteracts another neurotransmitter that limits neuroplasticity called GABA.
Long-Term Benefits of Exercise on Cognitive Performance
The long-term effects of aerobic or endurance exercise on cognitive performance have been studied extensively. Evidence from large scale observational studies shows a dose-response (the more, the better) relationship between regular exercise and reductions in brain volume loss and cognitive decline. Moderate-intensity (about 75% - 85% of your maximum heart rate) physical activity equivalent to at least 30 minutes five times per week appears to be protective against age-related brain changes.
Physical activity below this level over a 10-year period was associated with brain volume loss specifically in the medial temporal lobe, which is associated with memory and executive function (Kirk-Sanchez & McGough, 2014). Other studies using cognitive performance tests corroborate the findings that exercise is inversely associated with cognitive decline and onset of neurodegenerative disease. However, a flaw of observational research is the inability to control for all possible contributing factors. Not surprisingly, it is likely that individuals who exercise regularly have healthier lifestyles, thus, contributing to better long-term cognitive performance.
Randomized controlled trials on aerobic exercise in older individuals with memory issues showed substantial increases in cognitive improvement after 12 weeks. Most randomized controlled trials on resistance training suggest a minimum of 6 months of training before positive effects on cognition can be detected. It is important to keep in mind, however, that results for individuals with existing cognitive issues may be more delayed when compared to those without clinical symptoms.
What is the Optimal Dose of Exercise for Cognitive Performance?
While the volume necessary to stave off cognitive decline appears established, the optimal dose and type of exercise are less clear. Interestingly, one study found that exercise intensity and variety, not duration, reduced dementia risk by half over a 5-year period (Angevaren et al., 2007). Exercise variety involves learning new motor (movement) skills which can act as an analog for overall cognitive performance. One study reported improvements in learning retention of an eye-tracking task up to 7 days following an acute bout of high-intensity interval cycling that was performed before learning (Taubert, Villringer, & Lehmann, 2015). When high-intensity exercise was performed after learning the eye-tracking task, learning retention was even better. Biomarker analysis showed high correlations between learning retention and concentrations of lactate, BDNF, and adrenaline. The researchers believe that exercise-induced neurological enhancements after learning improve memory consolidation.
High-intensity interval training (HIIT) has been shown to elicit higher amounts of BDNF when compared to continuous exercise which is attributed to higher lactate concentrations. HIIT is a popular mode of exercise characterized by short intervals of high-intensity exercise followed by short periods of light exercise or rest. HIIT has gained popularity because it allows individuals to increase their aerobic capacity and burn more calories when compared to continuous aerobic exercise (typically performed at lower intensities) of similar durations. In theory, longer and less-intense exercise may have a similar effect if lactate levels increase, however, HIIT will raise lactate levels much faster.
How to Perform HIIT
First, consult with your doctor prior to performing HIIT to be sure you have no contraindications to high-intensity exercise. Pick your preferred method of exercise. To keep it simple, pick a mode of exercise that you would normally do for longer periods of time such as running, cycling, or the elliptical. Warm-up for 3-5 minutes at a lower intensity. If you are not taking any heart rate-limiting prescription drugs such as certain blood pressure medications, I would recommend wearing a heart rate monitor to ensure you are reaching the appropriate intensity. To perform HIIT properly, you should be aiming to reach about 90% - 95% of your maximum heart rate during your high-intensity intervals. To estimate your maximum heart rate, use the following formula: 207 – (0.7 x your age). So for example, if you are 50 years old, your maximum heart rate would be 172 beats per minute. When you are ready, ramp up the speed and/or the resistance to an all-out intensity (9 or 10 on a 1-10 scale of exertion or 90% of your maximum heart rate). To start, I would recommend intervals no longer than 30 seconds. Follow- up the high-intensity interval with a period of low speed or light resistance until you can breathe comfortably or your heart rate drops to about 65-70% of your maximum, then repeat this process. Be sure to progress the duration of your workouts. The benefits can be experienced in as little as 5-10 minutes, but you’ll want to increase the duration as you become fitter.
Adam Eckart, Executive Contributor Brainz Magazine
Dr. Adam Eckart is an Assistant Professor in the School of Health and Human Performance at Kean University. Dr. Eckart holds a Doctorate of Health Sciences from A.T. Still University, a Master's of Science in Exercise Science, and a Bachelor's of Arts in Adult Fitness from Kean University. Dr. Eckart holds a plethora of industry certifications including the Certified Strength and Conditioning Specialist, USA Weightlifting Level One, Precision Nutrition, Functional Movement Screen, ACSM Exercise is Medicine, and Advanced Cardiac Life Support certifications, among others. Eckart's research interests include exercise and lifestyle medicine with a focus on the convergence of genetics, exercise and nutritional interventions, and chronic diseases. Dr. Eckart has 15 years of experience as a personal trainer and fitness business owner allowing him to blend the theoretical and practical applications of sports, fitness training, and behavior change.
References:
Angevaren, M., Vanhees, L., Wendel-Vos, W., Verhaar, H. J., Aufdemkampe, G., Aleman, A., & Verschuren, W. M. (2007). Intensity, but not duration, of physical activities is related to cognitive function. European journal of cardiovascular prevention and rehabilitation : official journal of the European Society of Cardiology, Working Groups on Epidemiology & Prevention and Cardiac Rehabilitation and Exercise Physiology, 14(6), 825–830. https://doi.org/10.1097/HJR.0b013e3282ef995b
Duan, W., Guo, Z., Jiang, H., Ware, M., & Mattson, M. P. (2003). Reversal of behavioral and metabolic abnormalities, and insulin resistance syndrome, by dietary restriction in mice deficient in brain-derived neurotrophic factor. Endocrinology, 144(6), 2446-2453.
Kirk-Sanchez, N. J., & McGough, E. L. (2014). Physical exercise and cognitive performance in the elderly: current perspectives. Clinical interventions in aging, 9, 51–62. https://doi.org/10.2147/CIA.S39506
Mattson, M. P. (2012). Evolutionary aspects of human exercise—born to run purposefully. Ageing research reviews, 11(3), 347-352.
Miranda, M., Morici, J. F., Zanoni, M. B., & Bekinschtein, P. (2019). Brain-derived neurotrophic factor: a key molecule for memory in the healthy and the pathological brain. Frontiers in cellular neuroscience, 13, 363.
Taubert, M., Villringer, A., & Lehmann, N. (2015). Endurance exercise as an “endogenous” neuro-enhancement strategy to facilitate motor learning. Frontiers in Human Neuroscience, 9, 692.
University of South Australia. (2020, September 24). World first study links obesity with reduced brain plasticity. ScienceDaily. Retrieved December 17, 2021 from www.sciencedaily.com/releases/2020/09/200924101936.htm
Voss, P., Thomas, M. E., Cisneros-Franco, J. M., & de Villers-Sidani, É. (2017). Dynamic brains and the changing rules of neuroplasticity: implications for learning and recovery. Frontiers in psychology, 8, 1657.
