Does exercise make you smarter and happier? Read what the current evidence has to say about exercise's effect on your brain!
In today’s modern world, it has become increasingly easier to remain inactive for long periods of time. Office jobs that leave many people sitting for most the day with little activity can have serious consequences not only on our muscles, but on our brains as well. If you find yourself achey, sluggish, and not as mentally sharp as you used to be, it might have something to do with your activity levels. While aging is something we cannot avoid, the side effects that are often associated with aging (forgetfulness, memory loss,) may actually be due to lower levels of physical activity. In fact, many chronic diseases are linked to low levels of physical activity (1). Instead, if we make exercise a regular routine in our lives (like we do brushing our teeth, showering, etc), many chronic diseases (Type II diabetes, cardiovascular disease, to name a few) can be prevented. Not only will you look great, but you will find yourself feeling and thinking better as well!
How does physical activity play a role in brain health across the lifespan?
Starting from a young age, the fitness and cognitive connection supports greater academic performance in children with higher fitness levels. In other words, children who are more physically active perform better in the classroom. Neuroimaging research shows that children who are more aerobically fit are better able to focus, regulate, and monitor their mistakes than children who are less active (8). Additionally, more research continues to support the relationship between higher fitness levels and positive brain function in young adults.
What about as we get older? Physical activity tends to decline as we age, which can set the brain up for decline. Current research provides evidence of improved cognitive performance, brain function and structure in older adults with regular exercise training. It is becoming increasingly established that exercise provides a protective factor against the effects of aging (4).
I know what you’re thinking – how? What kind of exercise is the “best”? Both resistance (weight training) and aerobic (lower intensity, continuous) exercise are effective at improving how the brain works.
What does the research say?
Resistance training:
Studies show that resistance training provides cognitive benefits – improved memory performance and verbal concept formation among older adults. (8). This is Important for adults at risk for Alzheimer’s disease as these processes become severely impaired.
Resistance training increases levels of IGF-1 (Insulin-like growth factor) which promotes growth, survival, and differentiation of brain cells (neurons) and improves cognitive performance. So, pumping some iron isn't just for muscles! Boost your brain by training with weights a few times a week.
Aerobic training?
Aerobic training results in the generation of new neurons and blood vessels. This happens in different regions in the brain such as in the hippocampus – involved in learning and memory, the cerebellum – controls movement, coordination, speech, and the primary motor cortex – responsible for executive function. The increase in neurons and blood vessels allow the cells to communicate more efficiently and ultimately improves cognitive function (8). In other words, movement = brain power!
New neurons and blood vessels emerge when we continually exercise to improve blood circulation – this helps deliver oxygen more rapidly to the tissues (like muscles). As fitness levels increase, so does perfusion (blood flow) in the brain. This means the brain can effectively communicate between neurons. Think about trying to talk to someone on the phone in an elevator. It’s hard to hear and communication takes a long time to get the message across. The brain responds more effectively to these signals when cells send and receive messages clearly.
As you can imagine, multiple adaptations of exercise are important for brain health – so incorporating both aerobic and resistance training is beneficial.
Chemical adaptations:
Exercise increases production of important neurochemicals such as BDNF and IGF-1. Brain-derived neurotrophic factor – (sounds like a mouthful, right?) is a chemical produced by the brain that supports neuron (brain cell) growth and survival. BDNF is most commonly produced and important for function in the hippocampus, which aids in learning and memory processes. Low levels of BDNF are associated with neurological decline and brain aging. By keeping these chemical levels high, the brain remains more “plastic” or better able to adapt with age (2).
Improvements can be seen after short bouts of high intensity exercise as well as with chronic aerobic activity! IGF-1 (insulin-like growth factor 1) is a neurotrophic factor developed in response to aerobic and resistance training. IGF-1 promotes growth of new neurons in the hippocampus, new blood vessels, and supports brain plasticity and recovery.
Aerobic exercise enhances several neurotransmitters (chemical messengers) including dopamine, serotonin, and acetylcholine – important for mood, reward, and cell signaling and processing (8).
Another positive effect of exercise is the increased production of neurochemicals that promote growth, differentiation (specialization of undifferentiated cells), survival, and repair of brain cells. This means that when our brains are hard at work, supporting cells clean up any damage and keep brain functions running smoothly.
Structural adaptations:
Exercise improves the structural integrity of the brain! Certain areas of the brain that shrink with age or with disease show an increase in size in response to regular exercise training. The hippocampus is an important region of the brain associated with learning and memory. In Alzheimer’s disease, this area becomes impaired and shrinks as the disease progresses. Exercise can attenuate this effect by increasing the volume of the hippocampus and provide treatment to older adults with memory impairment as well as by preventing shrinkage of this region (3, 8).
Exercise continues to attenuate the effect of Alzheimer’s disease by degrading excess protein. The amyloid protein, when it is not cleared, causes plaque and disrupts metabolism in the brain. By clearing the buildup, blood flow and insulin sensitivity are restored, meaning communication and ability to use energy are improved.
Metabolic adaptations:
Just like other areas of the body, the brain needs fuel to work properly. The brain prefers to use glucose and is affected by insulin sensitivity (being able to regulate energy properly). When the body’s glucose levels are chronically elevated, insulin function can become impaired – this means it stops responding to these signals to lower blood sugar (a main cause of type II diabetes). Exercise provides an insulin-like effect by improving the ability to respond to glucose (Ivy). Muscle contraction results in a pathway that allows glucose to enter the cell independently of insulin, meaning people with insulin resistance can use exercise to promote better glucose metabolism. The combination of exercise and improved insulin sensitivity is a key factor in the prevention and treatment of Alzheimer’s disease (2, 5, 9).
All of these factors allow the brain to respond and adapt to new experiences and environments and ultimately perform better in everyday life!
Does exercise improve mood?
Exercise plays another role in the promotion of brain health – alleviating symptoms of depression. Exercise can be used as alternative treatment or prevention of depression on its own or in combination with anti-depressant drugs or therapy (6). Exercise is a safe, cost-effective method with positive benefits including improved mood, skill mastery, social interaction, distraction, improved self-image, and enjoyment of exercise that all contribute to the psychosocial improvement of depressive symptoms. Inflammatory markers are reduced (cortisol, TNF-A, IL-1B, IL-6) in the body as levels of certain neurotransmitters (serotonin, endorphins, and endocannabinoids) increase, which are important for regulating mood, reward, and providing pain relief (7).
While there is still some debate about the type and duration of exercise programs, it is agreed that both aerobic and resistance training programs produce positive effects, and a total of 150 minutes of moderate-intensity activity is sufficient (6). Every individual is different, so choosing something enjoyable – recreational activities, individual training, group exercise, resistance or aerobic training – is all acceptable!
Takeaway:
Incorporating exercise into your weekly routine can have significant health benefits across all ages and fitness levels. Exercise is beneficial for generation of new neurons, blood vessels, and promoting chemicals in the brain that help to boost cellular function, reduce harmful protein buildup, and improve blood flow and energy utilization. Exercise has a protective effect on aging and can prevent cognitive decline in areas of the brain that are associated with learning and memory (2), (hint: remember the Hippocampus?)
When is the best time to start exercising to optimize brain health? Right now! Benefits and improvements are seen in children, young adults, and can provide lasting brain health into older adulthood. There is a strong connection between high levels of physical activity and higher levels of cognitive performance and lower risk of disease (1, 4, 8). In other words, staying active regularly can help your brain function better across the lifespan (8). If you are active - keep on going! If you are looking for the right time to start exercising - here it is! Even taking small activity breaks can make an impact (10-minute walk here and there, for example) - something is always better than nothing.
What’s the best way to do this? Both aerobic and resistance training have shown positive benefits, so a combination of both is a great way to optimize brain health. Running, hiking, swimming, high intensity interval training, weightlifting, calisthenics (body weight exercises) to name a few are all good examples of ways to keep the body moving and functioning at its best. Remember - the best exercise is the one you will consistently do. So, try new things, find something you enjoy, and keep doing it! Break up your day with small bouts of activity – getting up and taking a walk or stretching to avoid sitting all day long. Big take away – sit less, move more.
Now that we know why and how exercise is important for cognitive and emotional health (just to name a few), the big question is how do we get started?
I’m glad you asked! Pittsburgh Fitness Project offers so many varieties of exercise to let you decide what works best for your lifestyle. Group fitness classes, individualized training, open gym, barbell club, coupled with exercise instructors and personal trainers to help guide your fitness journey are readily available. For the wellness side of things, nutritional counseling and massage therapy are also offered. For more opportunities on how to become more active, visit www.pittsburghfitnessproject.com to get started on your fitness journey today!
In strength and health,
Marisa Galli
BS, MS, NSCA-CSCS
References:
1. Booth, F., Roberts, C., & Laye, M. (2014). Lack of exercise is a major cause of chronic diseases. Comprehensive Physiology, 2(3), 1143-1211.
2. Duzel, E., van Praag, H., & Sendtner, M. (2016). Can physical exercise in old age improve memory and hippocampal function?. Brain, 139(3), 662-673. doi: 10.1093/brain/awv407
3. Erickson KI, Voss MW, Prakash RS, Basak C, Szabo A, Chaddock L, et al. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci USA 2011; 108: 3017–22.
4. Garatachea, N., Pareja-Galeano, H., Sanchis-Gomar, F., Santos-Lozano, A., Fiuza-Luces, C., & Morán, M. et al. (2015). Exercise Attenuates the Major Hallmarks of Aging. Rejuvenation Research, 18(1), 57-89. doi: 10.1089/rej.2014.1623
5. Heneka MT, Fink A, Doblhammer G. Effect of pioglitazone medication on the incidence of dementia. Ann Neurol 2015; 78: 284–94.
6. Ranjbar, E., Memari, A., Hafizi, S., Shayestehfar, M., Mirfazeli, F., & Eshghi, M. (2015). Depression and exercise: a clinical review and management guideline. Asian Journal Of Sports Medicine, 6(2), 1-6.
7. Sparling, P., Giuffrida, A., Piomelli, D., Rosskopf, L., & Dietrich, A. (2003). Exercise activates the endocannabinoid system. Neuroreport, 14(17), 2209-2211. doi: 10.1097/00001756-200312020-00015
8. Voss, M. W., Nagamatsu, L. S., Liu-Ambrose, T., & Kramer, A. F. (2011). Exercise, brain, and cognition across the life span. Journal of Applied Physiology, 111(5), 1505–1513. http://doi.org/10.1152/japplphysiol.00210.2011
9. Yarchoan M, Arnold SE. Repurposing diabetes drugs for brain insulin resistance in Alzheimer disease. Diabetes 2014; 63: 2253–61.
