Diet and Exercise for a Healthy Heart - hidden-facts.info
The association between blood lipids and cardiovascular health is highly exercise is included as a behavioral intervention along with dietary. Exercise and Cardiovascular Health The association of changes in physical- activity level and other lifestyle characteristics with mortality among men. N Eng J . Over the past 40 years, numerous scientific reports have examined the relationships between fitness level, physical activity, and cardiovascular.
To normalize such stress and to meet the systemic demand for an increased blood supply, the heart undergoes morphological adaptation to recurrent exercise by increasing its mass, primarily through an increase in ventricular chamber wall thickness. This augmentation of heart size is primarily the result of an increase in the size of individual terminally differentiated cardiac myocytes Adaptive remodeling of the heart in response to exercise typically occurs with preservation or enhancement of contractile function.
This contrasts with pathologic remodeling due to chronic sustained pressure overload e. Recent work in experimental animal exercise models has identified several cellular and molecular alterations involved in the physiologic growth program of the heart that accompanies exercise conditioning.
Whereas pathologic remodeling of the heart is associated with a reduction in oxidative energy production via fatty acid oxidation and more reliance on glucose utilization, mitochondrial biogenesis and capacity for fatty acid oxidation are enhanced following exercise 77 A recent study suggests that changes in myocardial glycolytic activity during acute exercise and the subsequent recovery period can also play an important role in regulating the expression of metabolic genes and cardiac remodeling Untargeted approaches have identified other major determinants of transcriptional programs that drive the exercise-induced hypertrophic response.
Other transcriptional pathways known to be activated by pathologic stimuli and cardiac hypertrophy, such as NFATc2, are decreased in exercise models 7984suggesting that some signaling pathways activated during exercise-induced growth program may directly antagonize specific factors that promote pathological remodeling.
In addition to metabolic and molecular remodeling, exercise can also promote functional adaptation of the heart, which may ultimately increase cardiac output and reduce the risk of arrhythmia.
Clinical studies have shown that exercise-trained individuals have improved systolic and diastolic function 8586while results of studies using animal models of exercise show that endurance exercise promotes enhanced cardiomyocyte contraction-relaxation velocities and force generation 87 — During pathologic remodeling of the heart, electrical instability can result from a lack of upregulation of key cardiac ion channel subunits associated with action potential repolarization relative to an increase in myocyte size In contrast, increased myocyte size in physiological hypertrophy is associated with the upregulation of depolarizing and repolarizing currents, which may be protective against abnormal electrical signaling in the adapted heart 95 Blood and vasculature The oxygen carrying capacity of blood, determined by the number of circulating erythrocytes and their associated intracellular hemoglobin concentration, is an important determinant of exercise performance and resistance to fatigue Yet, overall total erythrocyte mass is increased in athletes, especially those who train at high altitude This is in part due to a dose-dependent effect of O2 on hypoxia-inducible factor HIF -mediated erythropoietin production as well as upregulation of erythropoietin receptors, iron transporters, and transferrins Multiple studies have shown that hematopoiesis is enhanced immediately following exercise Nonetheless, the physiological significance of these responses remains unclear, as the effects of exercise on angiogenesis and the wound healing response have not been systematically studied.
The resistance arterial vascular network also undergoes functional and structural adaptation to exercise During acute exercise, small arteries and pre-capillary arterioles that supply blood to the skeletal muscles must dilate to increase blood flow through the release of vasodilatory signals e. Repeated exercise leads to an adaptive response in skeletal muscle arterioles that includes increased vascular density coupled with greater vasodilatory capacity, such that enhanced perfusion can occur after conditioning — This may be partly due to adaptation of the endothelium to the complex interplay of recurrent variations in hemodynamic stresses and vasodilatory stimuli of exercise.
A similar adaptive response to exercise has also been noted in the coronary vasculature, which must dilate to meet the increased metabolic demands of the myocardium Exercise-trained humans and animals demonstrate reduced myocardial blood flow at rest, which may reflect a reduction in cardiac oxygen consumption primarily as a result of lower resting heart rate However, a large body of evidence suggests that multiple mechanisms converge to enhance the ability of the coronary circulation to deliver a greater supply of oxygen to the conditioned myocardium during exercise.
This includes structural adaptations consisting of an expansion in the density of intramyocardial arterioles and capillaries as well as enhanced microvascular collateral formation — Additionally, like skeletal muscle arterioles, coronary arterial network enhances its responsiveness to vasoactive stimuli via a number of distinct mechanisms including, but not limited to, augmentation of endothelial NO production, altered responsiveness to adrenergic stimuli, or changes in the metabolic regulation of vascular tone — In addition, some studies implicate hydrogen peroxide H2O2 -mediated vasodilation in opposing exertion-induced arterial dysfunction in overweight obese adults after a period of exercise training, suggesting enhanced contribution of NO-independent mechanisms to improved microvascular endothelial function with exercise.
Collectively, these adaptations may act to support enhanced myocardial function and increased cardiac output during repeated exercise, and increased total body oxygen demand following exercise conditioning.
Further advancement of our understanding of how blood flow is improved in response to exercise could lead to novel therapeutic strategies to prevent or reverse organ failure in patients resulting from inadequate blood flow. Concluding remarks and remaining questions to be addressed Despite the extensive body of knowledge documenting the unequivocal health benefits of exercise, a vast majority of Americans do not engage in sufficient physical activity Nonetheless, mortality risk reduction appears with even small bouts of daily exercise and peak at 50—60 min of vigorous exercise each day However, the question remains as to how much exercise is optimal for cardiovascular health benefit.
Studies in endurance runners show that the frequency of adverse cardiovascular events in marathoners is equivalent to that in a population with established CHD, suggesting that too much exercise may be detrimental An upper limit for the cardiovascular benefits of exercise is further supported by a recent study showing that individuals who completed at least 25 marathons over a period of 25 years have higher than expected levels of coronary artery calcification CAC and calcified coronary plaque volume when compared with sedentary individuals In contrast, other studies report greater plaque stability due to calcification in exercisers, thus indicating that with higher levels of physical activity, plaque quality may be favorably impacted to lower the risk of cardiovascular events, despite a higher incidence of plaques and normal CAC scores It can also contribute to or worsen heart failure in some people.
How much should I weigh? Talk to your family doctor about your ideal weight, because every person is different.
Exercise and Cardiovascular Health - Center for Nutrition Studies
Exercise Exercise makes your heart stronger. This helps it pump more blood with each heartbeat. This delivers more oxygen to your body. With more oxygen, your body functions more efficiently. Exercise can also lower blood pressure. Bad cholesterol can clog the arteries and can cause a heart attack. When combined with a healthy diet, exercise can speed up weight loss. It makes your heart work harder to pump blood.
Aerobic exercise also raises your heart rate which burns calories. Examples of aerobic exercise include walking, jogging, running, dancing, swimming, and bicycling. How much exercise do I need? Your doctor may recommend a different exercise regimen based on your health. Alternate exercise days with rest days or days you do a very different type of exercise. This will help prevent injuries. How will I fit exercise into my busy schedule? There are lots of ways to raise your heart rate during your regular day.
Take the stairs instead of the elevator. Walk during a coffee break or lunch.
Walk to work, or park at the end of the parking lot so you have to walk farther. Do housework at a quicker pace and more often for example, vacuuming every day. Rake leaves, mow your lawn, or do other yard work.
Things to consider Diet and exercise are an important part of your heart health. But the limited number of studies in humans have had mixed results.
A recent study of the relationship between exercise, body mass index BMI, a measure of obesitycaloric intake, and death from cardiovascular disease CVD shows calorie counting is actually not the way to go.
Cardiovascular Effects and Benefits of Exercise
Researchers followed close to 10, healthy people age for 17 years. They found a lower level of activity and obesity were each associated with a greater risk of death from cardiovascular disease. Further, individuals who were the least active, obese, and consumed the fewest calories had a greater risk of death from CVD than individuals who exercised the most, were of normal body weight, and had the highest caloric intake.
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- Diet and Exercise for a Healthy Heart
- Exercise and the Risk of Stroke, Heart Disease—The Family HealthGuide
These results suggest caloric intake is not directly related to CVD deaths. Rather, the key to extending healthy life is not how much you eat, but how much energy you expend.