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Exercise more for brain health!

Exercise more for brain health!

 

People who exercise have better mental fitness, and a new imaging study from UC Davis Health System shows why. Intense exercise increases levels of two common neurotransmitters — glutamate and gamma-aminobutyric acid, or GABA — that are responsible for chemical messaging within the brain.

Published in this week’s issue of The Journal of Neuroscience, the finding offers new insights into brain metabolism and why exercise could become an important part of treating depression and other neuropsychiatric disorders linked with deficiencies in neurotransmitters, which drive communications between the brain cells that regulate physical and emotional health.

“Major depressive disorder is often characterized by depleted glutamate and GABA, which return to normal when mental health is restored,” said study lead author Richard Maddock, professor in the Department of Psychiatry and Behavioral Sciences. “Our study shows that exercise activates the metabolic pathway that replenishes these neurotransmitters.”

The research also helps solve a persistent question about the brain, an energy-intensive organ that consumes a lot of fuel in the form of glucose and other carbohydrates during exercise. What does it do with that extra fuel?

“From a metabolic standpoint, vigorous exercise is the most demanding activity the brain encounters, much more intense than calculus or chess, but nobody knows what happens with all that energy,” Maddock said. “Apparently, one of the things it’s doing is making more neurotransmitters.”

The striking change in how the brain uses fuel during exercise has largely been overlooked in brain health research. While the new findings account for a small part of the brain’s energy consumption during exercise, they are an important step toward understanding the complexity of brain metabolism. The research also hints at the negative impact sedentary lifestyles might have on brain function, along with the role the brain might play in athletic endurance.

“It is not clear what causes people to ‘hit the wall’ or get suddenly fatigued when exercising,” Maddock said. “We often think of this point in terms of muscles being depleted of oxygen and energy molecules. But part of it may be that the brain has reached its limit.”

To understand how exercise affects the brain, the team studied 38 healthy volunteers. Participants exercised on a stationary bicycle, reaching around 85 percent of their predicted maximum heart rate. To measure glutamate and GABA, the researchers conducted a series of imaging studies using a powerful 3-tesla MRI to detect nuclear magnetic resonance spectra, which can identify several compounds based on the magnetic behavior of hydrogen atoms in molecules.

The researchers measured GABA and glutamate levels in two different parts of the brain immediately before and after three vigorous exercise sessions lasting between eight and 20 minutes, and made similar measurements for a control group that did not exercise. Glutamate or GABA levels increased in the participants who exercised, but not among the non-exercisers. Significant increases were found in the visual cortex, which processes visual information, and the anterior cingulate cortex, which helps regulate heart rate, some cognitive functions and emotion. While these gains trailed off over time, there was some evidence of longer-lasting effects.

“There was a correlation between the resting levels of glutamate in the brain and how much people exercised during the preceding week,” Maddock said. “It’s preliminary information, but it’s very encouraging.”

These findings point to the possibility that exercise could be used as an alternative therapy for depression. This could be especially important for patients under age 25, who sometimes have more side effects from selective serotonin reuptake inhibitors (SSRIs), anti-depressant medications that adjust neurotransmitter levels.

For follow-up studies, Maddock and the team hope to test whether a less-intense activity, such as walking, offers similar brain benefits. They would also like to use their exercise-plus-imaging method on a study of patients with depression to determine the types of exercise that offer the greatest benefit.

“We are offering another view on why regular physical activity may be important to prevent or treat depression,” Maddock said. “Not every depressed person who exercises will improve, but many will. It’s possible that we can help identify the patients who would most benefit from an exercise prescription.”

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Exercise and the Brain: A winning team

Exercise and the Brain: A winning team

“The best way to improve mental performance, is to improve physical performance” – Tim Ferriss¹

So, how does exercise improve learning and memory?Learning requires repeated connection and communication between neurons in a process known as long term potentiation¹.

“Long term potentiation: The strengthening of brain cells’ capacity to send signals across a synapse for the purpose of learning and memory.“ – John Ratey M.D., from ‘Spark’.²

The more repeated this firing across a synapse, the stronger the connection becomes.

“Neurons that fire together, wire together.” – Dr. Daniel Siegel.³

With the example of learning a new language, nerve cells that are recruited in learning a new word will fire a glutamate signal across the synapse.²Without practice, the original synaptic connection will diminish, and the signal will weaken.²The end result, is you’ll forget. On the other hand, regular practice and firing of this new neural connection will strengthen the synapse. The synapse will actually grow in size, and this will improve the ability of the synapse to fire in the future.² And guess what? You’ll remember!

What parts of the brain are involved in memory? One area of the brain that we often read about in terms of memory is the hippocampus.The process of learning, however, involves many more areas of the brain working together.² When the brain receives an incoming stimulus, there is an emotional intensity assigned to it (limbic region), and it is considered amongst past experiences, as well as the social and environmental context, before being formed as a new memory in the hippocampus.The pre-frontal cortex is the decision maker of the brain . It sequences this information, and is able to make a rational decision or judgement about any particular scenario before it settles as a formed memory in the hippocampus.

Coming back to the hippocampus, research has shown that it is particularly vulnerable to degenerative disease.⁴Studies have shown that the hippocampus can literally shrink in size, during the course of degeneration such as dementia.²

The positive, though, is that research has also shown that cardiovacular exercise, as well as routine cognitive challenges (e.g., problem solving, learning a new language) can increase the size of the hippocampus.²

This is another example of neuroplasticity.

Brain-derived neurotrophic factor (BDNF) is crucial for the health of our nervous systems, and it massively increases during cardiovascular exercise.²BDNF is thought to play a really important role in learning, and has been found in lab studies to be present in the hippocampus.²Researchers have found that if BDNF is added to neurons in a petri dish, the neurons sprouted new branches (dendrites), which could be thought of like fertiliser for long term potentiation (learning).²BDNF also helps with synaptic connections, binding to receptors at the synapse and strengthening the neural signal.²

So how much, and what kind of exercise is effective?Unfortunately it still isn’t exactly known what is an ideal type and duration of exercise for improved learning and memory.²

Going by the recommendations of the World Health Organisation⁵, these are guidelines for general health:

Children aged 5-17 years

1.At least 60 minutes of moderate to vigorous intensity physical activity each day.
2.Any extra exercise will provide additional benefits.
3.Should be mostly aerobic exercise. Vigorous-intensity activities should be included, for safe and appropriate muscle strengthening, at least 3 times per week.

Adults aged 18-64 years:

1.At least 150 minutes of moderate-intensity aerobic exercise activity, or at least 75 minutes of vigorous-intensity aerobic activity in one week. (Or a comination of moderate and vigorous intensity activity).
2.Aerobic activity should be at least 10 minutes in duration.
3.For additional health benefits, adults should aim for double the above mentioned recommendation (300 minutes moderate intensity, or 150 minutes of vigorous activity, or combination, per week).
4.Muscle strengthening involving major muscle groups on 2 or more days a week.

Adults aged 65 years and above:

1.At least 150 minutes of moderate-intensity aerobic physical activity, or at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week (or equivalent combination).
2.Aerobic activity should be at least 10 minutes in duration.
3.For additional health benefits, adults should aim for double the above mentioned recommendation (300 minutes moderate intensity, or 150 minutes of vigorous activity, or combination, per week).
4.Balance and falls prevention for older adults with poor mobility, 3 or more days per week.
5.Muscle strengthening involving major muscle groups on 2 or more days a week.
6.When older adults cannot do the recommended amounts of physical activity due to health conditions, they should be as physically active as their abilities and conditions allow.

For anyone being treated for any medical condition, discuss these with your medical practitioner before starting a new exercise program.

For more detailed recommendations, please see the World Health Organisation’s website.

Dr Ratey suggests combining the benefits of cardiovascular exercise (e.g., 60-70% of maximum heart rate) with skill-based, non-aerobic exercise. This will depend on what each person enjoys, and will be able to be consistent with.²

Examples would be tennis, basketball, surfing, or any other activity that challenges both strength, balance, fine motor control, and cardiovascular endurance. This will help challenge and develop different areas of the brain, such as the cerebellum and basal ganglia.

Summary

•Exercise can play an important role in counteracting the neurotoxic effects of prolonged stress.

•Cardiovascular exercise encourages an increase in neurotransmitters, proteins, and hormones that help with neurogenesis and nervous system health.

•Cardiovascular exercise has been shown to considerably improve cognition and long term memory, by strengthening synaptic connections and encouraging neurogenesis (nerve cell growth).

•A combination of strengthening, fine motor skills, and cardiovascular activity seems to be a good way of challenging and developing different areas of the brain.

 

This thoughtful information is brought to you by the excellent website below, please check it out.

http://physiodevelopment.com/cardiovascular-exercise-improving-learning-and-memory/#more-2612

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