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.”
Feeling dizzy? You Could Have a Vestibular Disorder
Do you experience dizziness? Perhaps when rolling into or over in bed, or turning your head to one side?
Dizziness can be more than dehydration, a big night out, or a compulsion to spin in circles on your office chair. It can be a symptom of asymmetry in your body’s sensory systems.
The most common condition that causes dizziness is benign paroxysmal positional vertigo, or BPPV. The brain has three main mechanisms for perceiving how we interact with the environment around us. These are the visual, proprioceptive, and vestibular systems.
The visual system is self-explanatory. The proprioceptive system is a network of nerves in all of your muscles and joints that relay information about the position of those muscles and joints back to the brain. It is how you can close your eyes and still accurately position your arms and legs in different poses.
The vestibular system is located in your inner ear and is used to identify the position and movement of the head in space. This is the system commonly linked to dizziness and vertigo.
The vestibular system is made up of three perpendicular fluid filled canals in each ear, which relate roughly to the planes of movement.
These canals each have sensory nerves at one end that are made up of crystals resting on fine hairs. When you turn your head, the fluid moves through the canals and pushes on the crystals. This causes the hairs to move and stimulates the nerves.
Your response in each ear should be equal and opposite, and work in tandem with your visual and proprioceptive systems. If things are not working in tandem, then dizziness, vertigo (room spinning), or nausea may result.
Have you ever felt nauseated in a car, or on a boat? This is because your vestibular system recognises that your head is moving but according to your eyes, you are still or moving a different way.
Someone may have suggested looking out the window or finding the horizon. This is great advice as fixating on something which the car or boat is moving relative to, provides a visual reference point and reduces or eliminates the disagreement between the visual and vestibular system.
In patients suffering BPPV, a similar disagreement occurs but it is completely internal. It occurs when crystals in one ear canal become dislodged from the hairs and drift down into the canal. This can happen as a result of trauma but is just as frequently unrelated to any incident.
When the head is turned, the nerve stimulation in one ear is different to the other and a combination of dizziness, vertigo, and nausea can result.
Generally, this resolves in seconds, or in more severe cases last up to two minutes. Usually only one canal will be affected at a time so symptoms are commonly worse to one side, and occur most severely in a single plane of movement.
If you are dizzy due to asymmetry, then your physiotherapist can assess and treat it. Assessment of specific movements can isolate which ear and which canal is causing the problem and treatment involves techniques designed to use gravity and inertia to relocate the crystals back to where they belong at the end of the canal.
NOTE: If you are suffering from severe, sudden onset headache, or persistent dizziness, double vision or nausea that seem unrelated to any particular movement then consult a medical doctor immediately.
Figures suggest that around 80% of people experience back pain at some time in their lives. Back and neck pain can be very debilitating so how a physiotherapist manages back pain treatment is essential to secure a positive result. Back pain can be localised in and around the spine, but can also be experienced as sciatic pain. Headaches and migraines are also commonly caused by neck issues.
Exercise is important
Exercise is gaining recognition as playing a vital role in the long term recovery and in preventing many musculoskeletal injuries, including back and neck pain. Exercise compliments physiotherapy treatment management and achieve long term results when trying to prevent and rehabilitate pain and injury by correcting the underlying causes, not just seeking to stop the pain.
The underlying biomechanics that cause back and neck pain
Most back pain is caused by excessive loading placed on muscles, joints, ligaments, spinal discs, etc. due to poor core stability. Core stability is traditionally defined as; an individual’s strength and control of their lower back, pelvic and abdominal muscles in order to maintain optimal postural alignment of the lower back and pelvis.
However it is important to also include the shoulder girdle and rib cage, as the lower back and pelvis do not operate in isolation, and muscles throughout the torso must act in a coordinated manner in order to maintain optimal postural alignment and also to initiate biomechanically efficient upper and lower limb movements.
A good analogy to help understand core stability is to consider how a tent is supported. A tent is held upright by a rigid tent pole. The bones of your spine act like a tent pole, however your spine is not rigid, so it relies on the support of ligaments and deep stabilising muscles to hold adjacent vertebrae and to help maintain optimal postural alignment i.e. stabilise the spine. If the muscles that stabilise the spine, pelvis, rib cage and shoulder are weak or are poorly controlled then your spine will tend to collapse, just like a tent pole made from a piece of spaghetti. There are many muscles that attach directly onto the spine, pelvis, rib cage and shoulders. These muscles move our torso and limbs and also assist with stabilising the core, acting in a similar way that guide ropes help to keep the tent pole upright. If a tent had guide ropes that pulled more on one side than on the opposite side then the tent would lean, so too, if the muscles on one side pulled more than the other due to imbalances in strength and/ or flexibility, or these muscles compensate for weak stabiliser muscles then they will pull your body into a poor postural alignment. One very important difference to note is that a tent only requires “static stability” i.e. support to maintain a single stationary position, whereas, the human body must have “dynamic stability” to provide support and maintain optimal alignment of their core and limbs whilst moving in many different ways to participate in sport, work and daily living activities.
How a physiotherapist corrects biomechanical faults
Physiotherapists conduct a comprehensive physical assessment and then use this information to design a personalised exercise program to improve posture/ biomechanics, core stability, flexibility, functional strength, cardiovascular fitness, balance and coordination. Programs focus on achieving long term results by correcting the underlying biomechanics causes of your pain, improving the strength of muscles that support your back and neck and teaching efficient movement for your specific sport, work or daily living activities. Expert supervision by an Physiotherapist ensures that each client completes the exercises with good technique to prevent further injury, to ensure that the exercises are effective, and also to ensure that progressions are made at safe and appropriate times.
Headaches are a problem that affects at least 90% of us during our lifetime. There are multiple types of headaches that vary in symptoms and severity, with some of the more common types including tension-type, migraine and cervicogenic headaches. A number of headache types share common contributing factors to their source of pain, including that they often originate or are linked to the neck region. Some of the following signs may indicate that your headache may be neck related:
Pain and tension through the neck
Pain is initiated or increased with neck movement or prolonged neck posture
Neck range of motion is reduced
The pain may be more prominent or localised to one side, or may exist on both sides of the head
Pain may be experienced from the base of the skull and often refer around the skull or behind the eyes
There may be a feeling of dizziness or light headedness
History of acute trauma or repetitive trauma to the neck region
Diagnosis of headache type is critical for effective management and is an area where physiotherapists can utilise their assessment skills to help differentiate which type of headache is present. Physiotherapy invention can be very effective in managing headaches with a cervical spine (neck) related origin. A physiotherapist will assess the joints of your neck, associated muscles and neural structures to identify any abnormalities. Your posture and work ergonomics may also have a significant impact on headache development and persistence, which are areas that physiotherapists have expertise.
Physiotherapy management may include any of the following depending of your specific presentation and symptoms:
Soft tissue mobilisation/massage
Stretching of tight structures
Postural advice and correction
Strengthening of important neck stabilising muscles
Ergonomic assessment/advice for your work place set-up
Stress and tension management
If any of the above physical symptoms are sounding familiar you may find that your pain in the neck was the cause of your headache all along.