Participation in physical exercise has been associated with the reduction of a number of physical (cardiovascular disease, colon and breast cancer, and obesity) and mental (depression and anxiety) disorders across the adult lifespan.
Despite accumulated evidence for the importance of physical activity, 74% of adults in US do not meet the recommended guideline of at least 30 minutes of moderate-intensity physical activity on most days.
Various types of physical exercise have shown possible physical and psychological benefits. Psychological benefits include decreased depression, increased socialization and energy, affective changes, and mood elevation. In addition, exercise training is beneficial for patients with hypertension, diabetes, metabolic syndrome, coronary artery disease and myocardial infarction, compared to those who do not participate in any training.
1. Anti-stress effects of exercise;Chronic psychosocial stress, in the presence of physical inactivity, is likely to contribute to the epidemic of cardiometabolic and emotional disease of our society. On the other hand, daily regular exercise may prevent and stress responses of daily clife. The beneficial effects of regular exercise in preventing or ameliorating the metabolic and psychological comorbidities induced by chronic stress. These benefits are thought to derive from a central effect of exercise to reduce the sensitivity to stress and also peripheral actions influencing metabolic functions (Exercise for stress; 2006).
2. Anti-nociceptive effects of exercise; The clinical benefits of exercise therapy for chronic pain are well established. Exercise is an effective treatment for various chronic musculoskeletal pain disorders, including chronic low back pain, chronic whiplash associated disorders.
Afferent input in somatic nerve fibers has a significant effect on autonomic functions. Similarly, somatosensory neurons are also physiologically activated by strong muscle contractions induced by protracted exercise. Exercise produces rhythmic discharges in nerve fibers and cause the release of endogenous opioid and oxytocin (OXT) from the brain. Endorphin (opioid) levels have been observed to rise in the brain tissue of animals after both acupuncture and strong exercise (Exercise for pain; 2011)
3. Cardiovascular effects of exercise;Human studies demonstrated that chronic aerobic exercise regimens improve cardiovascular function in older people and those with cardiovascular risk factors.
Regular physical exercise corrected the endothelial dysfunction of the skeletal muscle vasculature and improved exercise capacity in patients with chronic heart failure. In patients with stable coronary artery disease, exercise training showed an improved endothelium-dependent vasodilatory capacity. Ten-week, aerobic and anaerobic exercise training enhanced endothelium-dependent dilation in healthy young men (Exercise for heart; 2012)
Free radicals are physiological byproducts of aerobic metabolism and are widely recognized for their dual roles as both deleterious and beneficial species, since they can be either harmful or beneficial to living systems. Mild oxidative stress can act as a stimulant of physiological antioxidant systems and as a trigger for various physiological adaptations.
The risk of cardiovascular events such as myocardial infarction or ischemic stroke was 3-4 folds higher in cardiovascular patients with endothelial dysfunction compared to those with a normal endothelial function.
The vascular endothelium plays a vital role regulating arterial dilation by manufacturing vasodilator (nitric oxide; NO). A key component of intact endothelial function is NO production by endothelial nitric oxide synthase (eNOS). The anti-inflammatory, vasodilatory and platelet inhibitory effect of NO have important roles in the maintenance of vascular hemostasis.
Physical activity increases vascular expression of eNOS in mice and humans. Exercise-induced up-regulation of vascular eNOS expression is closely related to the changes of frequency and the intensity of physical forces within the vasculature.
4. Improved memory function by exercise; Aerobic exercise can improve a number of aspects of cognition and performance. Exercise can help to improve the academic performance as well as physical health (Be smart by exercise; 2008).
Animal research has long shown that enriched environments, including access to exercise equipment (such as running wheels), has a positive effect on neuronal growth and on the neural systems that are involved in learning and memory.
Mechanisms believed to interface metabolism and cognition seem to play a critical role with the brain derived neurotrophic factor (BDNF) system. BDNF is a neurotrophin, a regulator of the survival, growth, and differentiation of neurons during development. BDNF functions to translate activity into synaptic and cognitive plasticity in the adult animal. BDNF is able to modulate the efficacy of neurotransmitter release, and stimulate the synthesis of vesicle-associated proteins.
In a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume. Increased hippocampal volume is associated with greater serum levels of BDNF (Erickson et al., 2011).