The many Benefits and effects of Exercise Prepared by: Rachael C. Anderson-Poulakidas
Physical Benefits The Benefits of Physical Exercise have been studied since the 1920’s, and have been shown to have a wide range of various health benefits. Physical benefits include: Lower risk of Coronary Heart Disease Lower Cholesterol Levels May reduce risk of Stroke Fewer instance of certain Cancers Diabetes Mellitus- physical activity may improve blood glucose levels and insulin sensitivity Lower Body Weight/Instance of Obesity (TJ Housh, DJ Housh, HA DeVries, 2003)
Cognitive Benefits Physical Exercise has many cognitive benefits including both increased mental health and correlation with increase in Working Memory and decrease in cognitive impairments attributed to age. Physical Exercise: Releases Endorphins which provide a level of natural pain reduction and increase feelings of well-being Reduced Symptoms of Depression Reduces Stress Levels Increases in Working Memory Lowers risk of Cognitive impairment Studies show exercise may be beneficial to recovery after injuries to brain and CNS (TJ Housh, DJ Housh, HA DeVries, 2003; McDonnell et al, 2011; Gazula et al, 2004)
Stress and Depression Endorphins are a group of about 10 neurotransmitters released during stress, pain and fear, as well as exercise and excitement. People who suffer from depression have decreased levels of endorphins causing sadness, sexual dysfunction, and problems sleeping. Antidepressants attempt to cure depression by elevating levels of endorphins, however they elevate levels so much transmitters believe the body has enough and stops making endorphins. Endorphins interact with the body’s Opiate receptors and are able to act similarly to medications like codeine and morphine, causing decreased pain levels with no addictive side effects. Endorphins are released during times of emotional stress in the limbic system and produce an euphoria that lessens melancholy and anxiety. Endorphins are released by the pituitary glands in response to such activities as: walking around the neighborhood, riding a bike, and other mild activities. (Mathew and Paulose, 2011)
Exercise and Memory While the underlying mechanism for the beneficial effects of physical exercise is not fully understood, several studies have shown a correlation between exercise and memory. It is thought that exercise increases catecholamines and neurotrophins that may have effects on cognition and memory. One study we’ll look at here uses three groups of adults between the ages of 50-72 and exposes them to three different varieties of exercise. Group 1 participated in medium-intensity aerobic exercise. (Nordic walking) Group 2 participated in low-intensity aerobic exercise. (Gymnastics) Group 3 was not placed on a formal exercise regiment between baseline and post assessments.
Memory cont’d Increased working memory was shown in all groups and was not exclusive to a certain level of activity, mild or moderate. However, the highest level of memory increase was among the mild aerobic activity group. Increases in gray matter were found in all levels of exercising individuals and not associated with specific level of activity. Physical exercise has shown decrease in risk for Parkinson’s and dementia. (R Ruscheweyh et al, 2011)
Memory Cont’d Fig. 3. Association of changes in physical activity and changes in episodic memory score. The graph shows the partial correlation after correcting for age, sex, education, and change in BDI. Therefore, group mean values are represented by “0” on both axes. (R Ruscheweyh et al, 2011)
Physical activity is not only beneficial for healthy aging and reducing risk of cognitive impairment, but is also likely to be beneficial for adults with neurological disorders. While exercise has been shown to improve cardiac function, mild cognitive impairment and cognitive capacity in healthy adults, the benefits for adults with neurological disorders has not yet been established. One study by McDonnell et al. looked at articles published and studies done all around the world to include in their analysis. McDonnell et al. found evidence in the articles reviewed that aerobic exercise had positive effects on cognition. Improvement in speed of information processing, global cognition, attention, and cognitive flexibility were all found among adults with neurological disorders such as TBI (Traumatic Brain Injury), MS (Multiple Sclerosis), and dementia. (McDonnell et al, 2011) Aerobic exercise to improve cognition.
This experiment looked at dendrite structure among rats with spinal cord injuries versus healthy rats, and how exercise may effect the injured rats’ dendrite structure. The experiment found severe atrophy of motor neurons, loss of dendritic membrane, and elimination of branching throughout the visible dentrites among the rats with spinal cords injury when compared to healthy rats. In contrast none of these markedly negative changes were visible in the rats who underwent exercise of the limbs after spinal injury. Findings suggest that a “dendritic tree of motor neurons deprived of descending influences is rapidly pruned”. (Gazula et al, 2004) Rat Experiment 1: Limb exercise after Spinal cord Injury
Rat Experiment 1 Cont’d Representative spinal cord sections that contain labeled motor neurons from the three experimental groups.
Rat Experiment 2:Environmental complextity This study looks at nervous system development in rats placed in complex environments versus sedentary environments. Enhanced neurotrophin expression appears to be the mechanism by with neurogenesis increases from physical activity. Neurotrophin factors include Nerve Growth Factor and Brain Derived Neurotrophic Factor. Environmental complexity has been associated with resistance to age-related impairments including decline in cognitive performance. In animal models this decline was reversed via exposure to increased environment complexity. While over-stimulation may be detrimental in extreme, animal models demonstrate complex environments and physical activity increased the animal’s cognition. (MH Lewis, 2004)
~An Interesting Side note~ Fibromyalgia is a disease effecting pain reception and resulting in widespread pain amplification. Fibromyalgia’s exact source is not yet known, but is a very real disease. My doctor assured me Fibromyalgia is NOT a psychological disorder but a very real and painful disease. Physical Exercise is one of the universal recommendations for regulating and hopefully improving fibromyalgia pain. (CC Marek, 2003; www.myalgia.com; and Personal Experience)
The Moral of this story? Exercise is GOOD! Aerobic exercise is defined as exercise that increases the need for oxygen, and is usually for a period of 15-20 minutes or more.
Annotated Bibliography *Gazula, V. R., et al. "Effects of Limb Exercise after Spinal Cord Injury on Motor Neuron Dendrite Structure." Journal of Comparative Neurology 476.2 (2004): 130-45. Print. This is a scientific paper detailing experiments performed on rats. This paper goes through the process if infecting certain rats to cause spinal cord damage and chronicles the rats deterioration thereafter. The paper contrasts healthy rats to sedentary rats with spinal cord damage versus rats with spinal damage exposed to exercise. *Housh, Terry J., Dona J. Housh, and Herbert A. DeVries. Applied exercise and sport physiology . Scottsdale, Ariz.: Holcomb Hathaway, 2003. Print. This is a book about the physiology of sports medicine. I expect that this book was a textbook at one time because it is presented in a textbook form. I used most chapters as it explains the effects of exercise throughout most all of the human body. Johnson, Arthur T.. "Exercise Limitations." Biomechanics and exercise physiology . New York: Wiley, 1991. 1-28. Print. This book discusses the benefits of exercise on the body’s different systems but also looks at exercise limitations. The chapter noted discusses extreme exercise fatigue and the turning point at which the benefit of exercise is lost. *Lewis, M. H. "Environmental Complexity and Central Nervous System Development and Function." Mental Retardation and Developmental Disabilities Research Reviews 10.2 (2004): 91-95. Print. This paper looks at rats in different levels of complex environments and how that affects their cognitive ability. The study shows that animals that are physically active and engage in more complex environments versus those that are more sedentary have higher cognitive ability. Knuttgen, Howard G., James A. Vogel, and J. R. Poortmans. Biochemistry of exercise . Champaign, IL: Human Kinetics Publishers, 1983. Print. This book looks at the chemical reactions that take place during exercise and how they affect the body. This book goes system by system describing the affect exercise has on an individual and the benefits or detriments therein. *Marek, Claudia. The first year--fibromyalgia: an essential guide for the newly diagnosed. New York: Marlowe ;, 2003. Print. This is a book that covers all sorts of information on fibromyalgia for patients of that diagnosis. I used this book for my last slide as another source recommending exercise for treating fibromyalgia.
Bibliography cont’d *Mathew, J., and C. S. Paulose. "The Healing Power of Well-Being." ActaNeuropsychiatrica23.4 (2011): 145-55. Print. This paper describes in details the functionality and effects of endorphins. This paper describes in detail the benefit of a positive mental state, and provides some proven methods on how to improve mental health. *McDonnell, M. N., A. E. Smith, and S. F. Mackintosh. "Aerobic Exercise to Improve Cognitive Function in Adults with Neurological Disorders: A Systematic Review." Archives of Physical Medicine and Rehabilitation 92.7 (2011): 1044-52. Print. This review looks at over a thousand individuals included in studies to provide proof to the hypothesis that physical exercise is beneficial to individuals with neurological disorders. This paper explains in detail the review methods used, and the evident found supporting the claims made. *"Treatment of Fibromyalgia." Fibromyalgia Information Foundation. N.p., n.d. Web. 9 July 2011. <http://www.myalgia.com>. This is a website prepared by a PhD and recommended to me by my rheumatologist. This website provides a comprehensive overview of fibromyalgia, treatments, support, and so on. This site has information from many qualified individuals on the subject. *Ruscheweyh, R., et al. "Physical Activity and Memory Functions: An Interventional Study." Neurobiology of Aging 32.7 (2011): 1304-19. Print. This study details cognitive ability of subjects both before and after interventional exercise programs. This paper monitors progress and find there to be cognitive improvement through exercise as well as increase in mass of gray matter. I did not include information about the increase in gray matter as the evidence was not as clearly defined. Zheng, Q. P., et al. "Exercise Improves Recovery after Ischemic Brain Injury by Inducing the Expression of Angiopoietin-1 and Tie-2 in Rats." Tohoku Journal of Experimental Medicine 224.3 (2011): 221-28. Print. This article looks at the cognitive improvement of rats through exercise after incurring brain injury. This article details the improvement in rats that physically exercised compared to rats that did not, and looks at the increased speed of recovery in physically active rats.