• Chaitanya Ankush Ghule

The Link Between the Brain and Exercise

Updated: Aug 9


We have heard the saying several times, “All work and no play makes Jack a dull boy.” Initially, this saying seemed as if it were a command from a physical activity instructor to a studious child who was engrossed in nothing but books, not playing or engaging in any sports during their schooling. However, it took a while to understand the underlying importance of that saying. Let’s say you are working the whole day with immense focus, but physically you are motionless. There have been changes in our workspace as we have adjusted to our lives post-pandemic. Unfortunately, as a result of the pandemic, we are working more, especially at the cost of our locomotion, physical fitness, body flexibility, muscle strength, and brain.


Now, the question arises, how is movement related to brain activity? Is cognition proportional to the physical mobility and flexibility of our body? As of recently, there has been an ample amount of research as to why physical mobility is correlated with cognitive capabilities, mindfulness, temperament, and emotional stability. There are several types of gym activities available: weightlifting, cycling, running, swimming, and high-intensity muscle training such as speed walking, running, hill walking, jump roping, Tabata training, cross country skiing, etc. Kinesiology research is exploring other methods which humans can inculcate in their current lifestyle to garner optimum results for their body and mind. Now, let's understand how the neuromuscular system integrates with locomotion. That twenty-minute walk in the park can relax our nervous system, helping us to assess changes at our physiological, psychological, and emotional levels to be conscious of our lives.


Emotions are influenced by several factors. One of the most important factors is physical activity. This is because in every action you perform, the nervous system activity is involved. We are all regulated by the central nervous system, which is further divided into the autonomous, enteric, and peripheral nervous systems. Research suggests that the neuromuscular system is influenced by the central nervous system. The neuroendocrine system’s coordination helps in memory, temperament, patience, and calmness while performing high-pressure activities such as professional sports, adventure sports, military training, mountain climbing, etc.


Do you ever wonder why athletes are mentally stronger or why physical training is a vital aspect of military training? There is a common link between these two common questions, let’s find out. According to several research studies conducted across the world in various institutions from several disciplines including anatomy, physiology, neurophysiology, psychology, and medicine, the answer is endorphins, which are associated with pain relief.


What is an endorphin? An endorphin is considered a neuropeptide or neurohormone released by the body when physical activity reaches a certain threshold where the muscles get worked out and begin paining. Therefore, it’s called an endorphin, as “endo” means from the inside. However, this pain is a good form of stress on the muscles, increasing their strength, core, and flexibility. Endorphins act as painkillers which reduce the pain and cause us to feel better after exercising. In a similar sense, Morphine, a painkiller prescribed by doctors, mirrors the effect endorphins have on the body. The human body is a wonderful machine as it secretes its own morphine to respond to pain.


However, are endorphins the only significant link between physical activity and brain activity? No, endorphins aren’t the only neuropeptide that is vital. There is a significant amount of protein called BDNF that is significant to cognition. BDNF is known as a brain-derived neurotrophic factor. It is also known as abrineurin. BDNF is found in the brain and periphery of blood cells. The protein is active in the hippocampus, cortex, and basal forebrain, functionally important in learning, memory, and intellectual thinking. The protein BDNF, in particular, is important for long-term memory. It is expressed in the retina, kidney, prostate, motor neurons, and skeletal muscle. Saliva also contains the BDNF protein.


Now that we know what BDNF protein is and its role in the human brain, let's see how it is secreted during exercise. BDNF is secreted more in plasma after physical activity as our heart rate increases during exercise. This causes the electron trafficking of more Ca2+ ions through the NMDA (N-methyl-D-aspartate) receptor in neurons. NMDA receptors regulate physiologic substrates for long-term memory functioning. Comparative studies have been done in rodents, young men, monkeys, and older men, which were based on comparisons between those experiencing sedentary lifestyles versus active lifestyles. During those research studies, it was found that exercise improved the participant’s muscular strength, increased blood circulation to the brain, and improved body posture, thus improving cognition, memory, alertness, and temperament.


The last important question is how much physical activity is necessary for optimum brain performance. The results differ across various researchers, but engaging in exercise an average of 3 to 4 sessions per week, where the person’s heart levels elevate between 120 to 140 beats per minute seems to be the consensus. In simple terms, aerobic exercises are beneficial for the brain as they increase the formation of neurons responsible for long-term memory in the hippocampus and neocortex, delaying cognitive decline. These cognitive benefits are increased if a person regularly engages in cardio exercise and aerobic exercises. Even a daily walk of 20 minutes without stopping is beneficial for an individual’s long-term memory and cognition.

 

Speaking Plainly:

  • Physical activity helps a person maintain their muscular strength and improve memory functioning and cognition, thus delaying cognitive decline and the development of neuromuscular disorders.

  • BDNF is a vital protein in the peripheral nerves. It is known as a brain-derived neurotrophic factor. The protein is increased when an individual engages in any physical activity, exercise, and muscular workouts.

  • BDNF plays a vital role in preserving long-term memory and cognition making it important in preventing Alzheimer’s. The protein can be found in the hippocampus, neocortex, and forebrain neurons.

  • Several researchers found that an increase in BDNF is found with cardio exercise and aerobics. An optimum level of recommended exercise is 3 to 4 sessions per week where the average heart rate is increased to around 120 to 140 bpm.