Did You Know Aerobic Exercise and Strength Training Affect Cognitive Ability?
Science has linked the benefit of physical exercise to brain health for many years. In fact, compelling evidence suggests physical exercise not only helps build cognitive power1 but also helps the brain resist shrinkage by promoting neurogenesis,2 i.e., the ability to adapt and grow new brain cells. Unfortunately, forgetfulness and “senior moments” are considered by many medical professionals to be a normal and anticipated part of aging.
I disagree. In fact, I believe if you’ve noticed memory lapses you may want to seriously consider making immediate lifestyle changes to help reverse or at least minimize further deterioration. Your brain is actually quite adaptable and has the capacity to repair and regenerate, the medical term for which is neuroplasticity. A recent study has found a strong correlation between grip strength and brain health.3
Your Muscle and Cognitive Power Are Connected
Researchers from Western Sydney University have found muscle strength, which they measured using hand grip strength, may be a strong indicator of the health of your brain.4 An analysis of data collected from over 475,000 British participants revealed the stronger an individual’s hand grip, the better they performed across every brain function test the researchers used, supporting previous research from the same university.5
During the study, the researchers evaluated reaction speed, logical problem-solving and multiple tests analyzing memory. Interestingly, they also determined the data was consistently strong both in individuals younger than 55 and those over 55. The analysis accounted for age, gender, body weight and education prior to confirming those who were stronger indeed had better functioning brains.6
A comparison of the results between the general population and individuals who suffered from schizophrenia found strong similarities. Grip strength was strongly correlated to brain health, particularly in working memory and processing speed.7 The researchers theorize if grip strength could predict functional and physical health outcomes in individuals who suffered from schizophrenia, further interventions to improve muscle strength could impact cognitive and real-world functioning.8
Although the correlation between muscle strength and physical activity to better brain health and cognitive function in seniors has been demonstrated in previous studies, the results from this study also revealed a strong connection in those younger than 55. Joseph Firth, Ph.D., from the National Institute of Complementary Medicine at Western Sydney University, commented on the results:9
“These sorts of novel interventions, such as weight training, could be particularly beneficial for people with mental health conditions. Our research has shown that the connections between muscular strength and brain functioning also exist in people experiencing schizophrenia, major depression and bipolar disorder — all of which can interfere with regular brain functioning.
This raises the strong possibility that weight training exercises could actually improve both the physical and mental functioning of people with these conditions.”
Aerobic Exercise and Strength Training Affect Cognitive Ability
Previous studies have also linked physical activity with an improvement in cognitive functioning, even for a short time. While studies have found exercising for at least 20 minutes has a measurable effect on cognitive functioning, one study demonstrated exercising for just 10 minutes could have a limited effect on cognitive performance following the exercise,10 suggesting even short bouts of exercise at work may improve productivity.
Although the researchers cannot explain the immediate cause of the benefits, theories include an increase in blood flow to the brain or a release of specific proteins, which have demonstrated neuroprotective benefits and the stimulation of new neurons.11 Regular aerobic exercise also appears to increase the size of your hippocampus, the area of your brain involved in verbal memory and learning.
Research from the University of British Columbia found resistance training, balance and muscle toning exercises did not have the same results on the hippocampus as aerobic exercise.12 Aerobic exercise, which has the benefit of simultaneously building large muscle strength and engaging your cardiovascular system, was found to improve vocabulary learning in one study.13 Participants who exercised during their workday also increased their productivity by 23 percent.14
In one test, participants pedaled on a stationary bike for 30 minutes and were able to improve scores on memory, reasoning and planning.15 In another, after running on a treadmill, subjects improved their performance by 20 percent on memory tests and demonstrated a 20 percent improvement on problem-solving abilities.16 Compiled death statistics find the top three killers are heart disease, cancer and chronic lower respiratory diseases.17
It is not a secret that regular exercise and good nutrition will dramatically reduce your potential risk for these conditions, yet nearly 80 percent of American adults don’t get the recommended amount of exercise each week.18 While exercise is critical, the nutritional choices you make each day also contribute greatly to building strong muscles and a strong cardiovascular system.
Make Smart Meat Choices
Cracking the code to build stronger muscles means addressing your body’s dietary needs and not just your perceived need for protein. While protein does help develop strong muscles, cell growth requires more than just one primary nutrient. In fact, there are several reasons why you do not want to eat more protein than your body can immediately use, which I will discuss below.
When choosing protein, it is important to choose wisely. Most meat at the grocery store today, unless otherwise labeled, is raised on a processed diet in confined quarters and injected with antibiotics — and producing low-quality nutrition. Instead, you want to seek out grass fed, organically raised beef and organic free-range dark meat chicken.
Choosing meat raised in concentrated animal feeding operations (CAFOs) may expose your gut microbiome to low-dose antibiotics, disturbing your gut flora, immune system and emotional health.19
Animals raised in CAFO systems also consume genetically engineered (GE) feed, like corn and soy, which are heavily contaminated with glyphosate, also patented as a very effective antibiotic against a large number of beneficial organisms. How your meat is labeled may help you find high quality meat. For instance, “Antibiotic-free,” “No antibiotic residues,” and “No antibiotic growth promotants,” have not been approved by the USDA and may be misleading, if not outright fraudulent.20
“Natural” or “All-Natural” is completely meaningless and has no bearing on whether or not the animal was raised according to organic principles. “Natural” meat and poultry products can by law receive antibiotics, hormones and GE grains, and can be raised in CAFOs. For the highest-quality beef, seek out products certified by the American Grassfed Association (AGA).
Your second-best choice is meat labeled, “100% USDA Organic,” “No antibiotics administered” and “Grass-fed” coupled with the USDA Organic label.21 When it comes to salmon, I strongly recommend eating only wild-caught Alaskan salmon or sockeye salmon, which are not allowed to be farmed. While farm-raised salmon may be less expensive in the store, they often carry a high health risk as testing revealed no less than 13 persistent organic pollutants, including carcinogenic PCBs and dioxins in farm-raised salmon.22
PCB concentrations are so high in farmed salmon researchers say:23 “Risk analysis indicates that consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.” Many farmed fish are also genetically modified to grow faster and larger than wild-caught species.
Although larger, you trade high grade nutritionally packed omega-3 fats in wild-caught Alaskan salmon for high levels of inflammatory omega-6 fats in farmed salmon. You can tell if your salmon is wild-caught or farm raised by the color and fat content. The flesh of wild sockeye salmon is bright red, courtesy of natural astaxanthin content. The flesh is also lean, with thin white stripes. If the flesh is pale pink with wide fat marks, the salmon is farmed.
Nutritional Choices Help Build Strong Muscles
Your nutritional choices to grow strong muscles don’t end with your choice of meat. Here are four more foods you’ll want to include:
• Macadamia nuts and pecans: Macadamia nuts have the highest fat, and lowest carb and protein content of any nuts. Pecans are also high in fat and low in protein and carbs, with abundant antioxidants and minerals. Most Americans get more than enough protein each day and instead need a higher amount of fat for fuel with low carbohydrates. Macadamia nuts and pecans are the perfect snack choice or addition to your chicken or salad.
• Organic broccoli and cauliflower: These two vegetables contain essential nutrients to promote fat loss, muscle recovery and muscle growth. Broccoli and cauliflower contain the chemical I3C, aiding in DNA repair.24 Both are good sources of folate,25 necessary for the production of new cell growth.26
• Organic blueberries: Blueberries may speed muscle recovery when they are eaten before and after exercise.27 Packed with antioxidants and anti-inflammatory properties, they can be grown in your garden so you can enjoy fresh blueberries throughout the growing season, and frozen to enjoy all year-round.
• Organic celery: Celery is a delicious, satisfying and crunchy snack, delivering high amounts of fiber and vitamins A, C, K, folate, potassium and manganese. Vitamin K supports the Gas6 protein, a cellular growth regulation factor necessary for the support of your heart, lungs, kidneys and cartilage.28 Vitamin K also regulates matrix γ-carboxylated glutamate (Gla) protein (MGP), found in cartilage and smooth muscle cells.29
Don’t Eat More Protein Than You Need
While protein is necessary to build strong muscles, too much can do more harm than good. There are adverse consequences to eating excessive protein, including the buildup of excess nitrogen waste products in your body, having a stimulating effect on the mammalian target of rapamycin (mTOR) pathway, and adversely impacting the GCN2 pathway involved in the aging process.
The recommended dietary reference intake30 for protein is 0.8 grams per kilo per day of body weight or about 46 grams of protein per day for the average sedentary woman and 56 grams for the average sedentary man. However, the average American eats nearly double or more.31
For optimal health I believe most adults need 1 gram of protein per kilo of lean body mass, not total body weight; approximately 0.5 grams of protein per pound of lean body mass. You’ll find a simple method of calculating your current protein requirements in my previous article, “Are You Sabotaging Your Health and Longevity by Eating Too Much Protein?”
Foods and Other Lifestyle Choices Improve Brain Function
While there is a strong correlation between exercise and cognitive performance, as with other organs in your body, your brain requires fuel. Your brain can metabolize either carbohydrates or fats for energy, but there is significant evidence the metabolic product of fats — ketones — may help restore and renew neurons even after damage has begun.
Ketones are not the only nutrients with a neuroprotective effect reducing reactive oxygen species in your brain. While blueberries have anti-inflammatory effects on your muscles, they also may help prevent, and are potential treatment of, cognitive deficits associated with Alzheimer’s disease.32 The combination of a ketogenic diet and the addition of blueberries may help improve memory.
In studies of participants who had mild cognitive impairment,33 both ketosis and blueberries helped improve memory in older adults.34 High levels of antioxidants in blueberries may also help reduce free radical damage, important for the prevention of DNA damage and diseases such as cancer.
Broccoli, cauliflower and celery have positive effects on muscle growth and recovery, and are also associated with brain health. Celery is a rich source of luteolin, a plant compound with a calming influence on inflammation in your brain, which is a primary cause of neurodegeneration. Luteolin has also been linked with lower rates of age-related memory loss in mice.35
Older mice fed a luteolin-supplemented diet scored better on learning and memory tasks. In addition to celery, peppers and carrots are also good sources of luteolin.
Broccoli and cauliflower are also good sources of choline, one of the B vitamins known for a role in brain development. Choline intake during pregnancy “super-charged” the brain activity of animals in utero, indicating it may boost cognitive function, improve learning and memory, and may diminish age-related memory decline.36 Broccoli offers additional benefits as well, including the anti-inflammatory flavonoid kaempferol and three glucosinolate phytonutrients working together to support your body’s detoxification processes.37
Protecting your brain health and cognitive function is essential if you would like to remain active and independent as you age. I share several more strategies to accomplish this goal in my previous articles, “How to Keep Your Brain Young,” and “How to Decrease Your Risk for Dementia By 90 Percent.”