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.”
Okay. So you’ve decided to embark on a fitness regime in order to shed some kilo’s, get fit or just for fun. New gym membership. Check. New sparkling runners. Check. Gym gear (a bit tight at the moment). Check. Alright, let me at that treadmill/rower/crosstrainer/zumba class!
“Hold on a second – what about your warm-up!”
“Warm-up” you scoff, “you’ve got to be kidding. No time to waste on that”.
Sorry folks, but the warm-up is an important part of your exercise routine and plays a crucial role in preparing your body for exercise. Skimp on the warm-up and you run the risk of injury during exercise or sport, as well as reduced performance levels.
“But what’s so important about doing a few stretches?” I hear you ask.
A proper warm-up involves more than just standing around stretching and talking. It prepares your body for the exercise/sport it is about to undertake and should simulate the actions involved.
The benefits of a warm-up are:
1) Increase in core body temperature
2) Preparation of muscles, tendons and joints for the stresses/strains of activity
3) Increase in nerve impulse conduction to muscles
4) Increase in blood flow to muscles
5) Increase in respiratory (breathing) rate
Let’s have a closer look at each of these benefits.
1. Increased core body temperature – this is important as it prepares the body for the change in activity level from being sedentary to exercising and gets the body into a ‘ready’ state. This also results in an increase in muscle temperature which makes them more pliable, supple and loose.
2. Prepares muscles, tendons and joints for activity – each sporting activity stresses the body in different ways so it is vital to prepare in a way that simulates these activities. For example, if you are a basketballer you need to include in your warm-up the jumping, running and change of direction that occurs during the game. If you pump weights at the gym, it is vital to perform a warm-up set of each exercise at a lower weight to allow your body to adjust to each specific movement.
3. Increased nerve conduction – muscles that are in a ready or aroused state react quicker and more efficiently than muscles that aren’t prepared for activity.
4. Increased blood flow to muscles – through increased blood flow there is an increase in oxygen flow to muscles as well as nutrient flow. This increased flow allows for improved performance
5. Increased respiratory rate – prepares the lungs for an increase in activity level and improves oxygenation of the blood flowing to the muscles.
Okay, so now that we know why we are performing a warm-up, what should it involve?
One common misconception out there these days is the importance of stretching as part of a warm-up. Note I said part of a warm-up.
Stretching on its own does not constitute a warm-up – rather it forms a critical part of one.
An effective warm-up has a number of very important key elements, which work together to minimize the likelihood of sports injury and prepare the individual for physical activity.
These key elements are:
1) The general warm-up
2) Static stretching
3) Sport specific warm-up
4) Dynamic stretching
1. The general warm-up
This consists of light physical activity such as walking, jogging, easy swimming, stationary bike, skipping or easy aerobics. The intensity and duration of the general warm-up is dictated by the fitness level of the participating athlete. For the average person, this part of the warm-up should last between 5 and 10 minutes and result in a light sweat.
2. Static stretching
Yes! Static stretching. This is a very safe and effective form of basic stretching. There is a limited threat of injury and is beneficial for overall flexibility. All the major muscle groups should be included for a period of 5 to 10 minutes.
Debate has raged about whether static stretching should be part of a warm-up and some studies have shown that static stretching can have an adverse effect on muscle contraction speed and therefore performance. It is for this reason that static stretching is performed early in the warm-up and always followed by sports specific drills and dynamic stretching. It is important these first two elements are completed properly as it allows the more vigorous and specific activities of elements three and four to then be performed.
3. Sport specific warm-up
In this part, you are specifically preparing the body for the demands of your particular sport or activity. During this part of the warm-up, more vigorous activities should be employed. Activities should reflect the type of movements and actions which will be required during the activity.
4. Dynamic stretching
Finally the warm-up should finish with a series of dynamic stretches. Caution should be taken with this form of stretching as it involves controlled, soft bouncing or swinging motions to take a particular body part past it’s normal range of motion. The force or the bounce of the swing is gradually increased but should never become radical or uncontrolled. These exercises should also be specific to the sport or activity.
Another important factor to keep in mind when undertaking any new exercise regime, is the time it takes for the body to adapt to training. If you have had a period of time away from sport or activity, then your body won’t be used to the stresses and strains put on it from exercise. It can take up to 4 to 6 weeks for your muscles, tendons and joints to become adjusted to the movements involved in your sport or activity.
During this period it is advisable to start with low to moderate intensity exercise which gradually builds over time. Heading straight up the red or blue arrow as your first exercise session in 3 or 4 months isn’t a great idea. Starting out with flat walks or jogging and gradually increasing time and intensity is a better way to start. After 4 to 6 weeks you will be at the stage where you can tackle more intense sessions.
The same goes for weight training. Starting with lighter weights and more repetitions will allow your tendons and joints in particular, to adapt to lifting load. Going too heavy too soon can lead to tendon injuries or severe muscle and joint soreness.
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.
Rice University catcher, John Clay Reeves, felt pain in his groin after a collision at the plate with an opposing player. He thought he had pulled a muscle, but it turns out he was suffering from a common condition seen in teens and young adults known as hip impingement.
“The issue with hip impingement is not treating it, but diagnosing it,” said Joshua Harris, M.D., a Houston Methodist orthopedic surgeon. “Ball and socket pain will be felt in the groin, which often leads to an initial diagnosis of a pulled groin. Some patients can spend six months to six years seeing three to five doctors before they finally get the correct diagnosis of hip impingement.”
Hip impingement occurs when either the socket or ball of the hip joint is not round, which prevents smooth movement within the joint. In most cases, this abnormal joint movement will lead to a tear of the hip labrum, a rim of cartilage that helps keeps the ball of the joint in the socket. Hip impingement can cause severe hip pain and, if not treated, might lead to the onset of arthritis in the patient’s 40s or 50s.
“We believe that most cases of hip impingement will begin in boys from 12 to 15 and girls from 11 to 13 who play high impact sports, such as soccer, track and basketball,” Harris said. “Between these ages, the bones are still growing and strengthening, so jumping too much can cause the socket and ball to hit repeatedly and will eventually cause one of them to lose their round shape.”
The good news is that the condition can be treated with arthroscopic surgery. An arthroscope, or small fiber optic camera is placed in the joint through a small incision at the hip. The surgeon will shave off bone as needed to make the socket and ball round again and will repair the labrum with sutures, which will relieve pain and improve function in 90 percent of cases.
While hip impingement is not yet preventable, Harris said it typically does not recur after arthroscopic surgery to treat it.
“More than 600,000 hip replacements are performed each year due to hip arthritis, with between 70 and 90 percent of hip arthritis cases stemming from untreated hip impingement,” Harris said. “We believe that treating hip impingement with arthroscopic surgery can delay or prevent the onset of hip arthritis, but studies to confirm that are still pending. Once it’s confirmed, we’ll have made significant headway in treating a large public health issue.”
Reeves has been catching since age 12 and has always experienced tightness in his hips. Since undergoing arthroscopic surgery, the tightness is gone and he’s ready to get back on the field.
“My hip would click and pop, which was painful, but then it would loosen up after stretching it out,” Reeves said. “I always thought it was normal, but I was able to tell a huge difference after having my right hip repaired last year. I’m now back to doing everything I was before with better flexibility and no pain.”
Houston Methodist. “Common hip issue in teens misdiagnosed as pulled muscle.” ScienceDaily. ScienceDaily, 24 February 2015. <www.sciencedaily.com/releases/2015/02/150224182524.htm>.