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.”
So we all know that feeling that we get after exercise – we feel generally happier, less stressed, less anxious and also sleep better. Exercise produces a rush of happy hormones we also know as endorphins. So what are these endorphins and why do they make us feel happy?
Endorphins are chemicals that are produced in our brains in response to stress or pain. Running, doing a hard workout, playing a sport or any exercise at all that increases our bodies stress response has the ability to make our brains release endorphins. The endorphins have the ability to travel through our neural networks as a neurotransmitter. One thing we do know about endorphins is that they make us feel really good. So how does this work then?
A part of the brain called the hypothalamus sends a signal to increase endorphin uptake through our bodies neural network when we subject ourselves to certain activities like exercise, sex, eat certain foods or experience pain. The endorphins then attach themselves to specific receptor sites within our neural network – these are called opioid receptors. These special receptors have the ability to block out pain signals and also to increase that euphoric happy feeling we get after we exercise. It is the same receptors that are locked onto when we take pain relief in the form of opiates.
Once we achieve a positive result in something we do, either though through exercise or simple activities like sticking to a plan you’ve made, your brain will also release another happy hormone called dopamine. Dopamine is responsible for us feeling addicted to pleasure seeking behaviors. By setting regular and achievable exercise goals that you reach it is highly possible to make exercise the trigger for your brain to release dopamine.
Serotonin is another one of our brains happy hormones that act as a natural anti-depressant. When we exercise serotonin levels in our brain increase and so does your level of happiness.
I know all these terms may seem confusing but there is another very important happy hormone called oxytocin. Oxytocin is released when we feel loved, cared for and connected to others. Your brain will also release oxytocin when you are kind to others.
So no matter how hard it may seem to get yourself moving on some days, putting one foot in front of the other and pushing yourself to move and exercise is not only good for your muscles and joints but also stimulates your brain. You’ll produce your very own happy hormones, reduces your stress levels and have you wanting to repeat it all over again next time. Give your fellow team mates, friends and family an encouraging kind words regularly as well- it will not only help them feel happy but will increase your happiness as well.
Lateral epicondylalgia or tennis elbow is the most common cause of musculoskeletal
pain located near the elbow. It is commonly known as tennis elbow as it can be a significant problem amongst tennis players. However, you do not need to play tennis to have experienced this injury. It is reported that approximately 40% of people will experience this type of pain at some point in their life and it usually presents in males or females aged between 35 and 54. Lateral epicondylalgia is an injury to the forearm muscles that act to extend the wrist and fingers. The point of injury occurs at the site where the muscle attaches to the bone near the elbow.
What causes tennis elbow?
Lateral epicondylalgia is usually caused by an overload of the forearm extensor muscles where the load is more than what normal muscle tissue can handle. Associated neck or shoulder pain may also contribute to the presentation. Common causes or activities can include:
Poor technique during sports or other activities i.e. racquet sports
Manual workers with jobs involving repetitive gripping and hand tasks
Office workers with jobs involving repetitive use of the keyboard and mouse
Symptoms of lateral epicondylalgia include tenderness over the side of the elbow and pain with activities involving gripping or wrist extension. There may also be areas of tightness through the forearms and pain when the involved muscles are stretched. Your physiotherapist will be able to diagnose this condition based on physical examination and gathering a complete history of your injury. Your physiotherapist may also send you for medical imaging scans to assist in ruling out other causes of elbow pain including muscle tears, ligament injury and elbow instability or pain that is originating from the neck.
The goals of treatment are to reduce pain, promote healing and decrease the amount of stress applied to the elbow. Also, to restore full strength and movement of the elbow and wrist. Early treatment may include:
Rest from aggravating activities
Exercise programs involving gradual strengthening and stretching
Massage and other soft tissue techniques
Taping to reduce load on the muscle and tendon
Acupuncture or dry needling
Once pain levels have decreased, physiotherapy will involve prescription of more difficult or specific strengthening exercises and correction of any predisposing biomechanical or technique problems. These are essential to prevent future aggravation and shorten recovery time.
Braces are available which are designed to assist in alleviating pain by reducing the amount of stress on the tendon. However, not all people will benefit from using a brace. Your physiotherapist will be able to guide you through all stages of rehabilitation.
Is barefoot best?
Barefoot and minimalist running is growing in popularity across the world, with Americans spending $59 million on minimalist running shoes last year alone! It has been hailed as the natural way to run and as a saviour to those plagued by running injuries. However, Doctors and new research agree that running without traditional running shoes may actually increase the risk of foot injuries.
A study published in last month’s Medicine and Science in Sports and Exercise looked at foot bone marrow edema after a 10 week period of running in Vibram Five Finger minimalist shoes. Twenty-six experienced runners were split into control and test groups, underwent an MRI scan and were instructed to continue running as normal. The test group were instructed to gradually transition to the minimalist shoes.
After the 10 week period, both groups were scanned again. The results indicated that of the 19 in the test group, the majority had developed at least grade 2 bone edema which indicates early bone injury. Three individuals had level 3 edema which the authors state to be ‘an actual injury’ and 2 runners had grade 4 edema – indicative of a stress fracture. Virtually all in this group had also spontaneously reduced their running loads, according to author Dr Ridge, “probably because their feet hurt”.
Running barefoot (or in minimalist shoes) has been shown to reduce the body weight impacted on the heel by up to 3 times the person’s weight. This and the change in biomechanics brought on by a mid or forefoot strike can contribute to a reduction in shin splints, tibial stress fractures and knee pain to name just a few.
However, the reduction in heel strike must increase the weight distribution anteriorly, which clearly increases in the bones of the forefoot. Barefoot runners could therefore expect higher rates of metatarsal stress fractures, calcaneal stress fractures and achilles tendonitis.
Whilst running barefoot was the way of our ancestors who ran to survive when hunting (and being hunted!) we should not compare our modern lifestyles to those of cavemen and tribes hundreds and thousands of years ago, or even those in the present day.
For a start, most of us pound the pavement, or at best tarmac for the majority of our runs. Cavemen and tribes certainly don’t (didn’t) do this! They would be (or would have been) running on softer, more forgiving grass and earth which allows far more shock absorption and less bone stress.
Secondly, they are more active populations who use their bodies as intended! For those with desk and driving based jobs especially, who spend large portions of their days in one position, muscle imbalances tend to develop. Weaknesses in some muscle groups and reduced flexibility in others results in altered movement patterns and increased stresses on joints and tendons etc. This leaves us more prone to injuries when we start to perform repetitive movements like running. For this reason, I don’t think we should be placing all the blame for running injuries at the door of footwear manufacturers and citing cavemen as reasons to run barefoot! There are plenty of other culprits out there!
The authors of this study state that:
“Runners interested in transitioning to minimalist running shoes, such as Vibram FiveFingers should transition very slowly and gradually in order to avoid potential stress injury in the foot.”
Substituting a mere mile per week of normal running at the start with one in minimal shoes “was probably too much,” Dr Ridge says. Running in this way may have been normal for our ancestors, but it is entirely new for most of our feet and requires a lot of adaptation and development of intrinsic foot strength.
There are also certain individuals who are advised not to transition to barefoot or minimalist shoes at all. Those with poor foot structure or clear biomechanical problems may not be suited to the stresses involved and so should stick to their running shoes. Dr Ridge is now looking in more detail at the runners who participated in her study, to determine if mileage, running form or body weight have more of an impact. The results of this are expected in the summer.