The health benefits of physical activity and cardiorespiratory fitness

It has been long hypothesised that it was strong relationship between physical activity and good health, and that the lack of physical activity has potential to increase risk of certain diseases. A contrary view was proposed in the mid-20^th century where bed rest became a common recommendation, including after myocardial infarction.

Evidence has conclusively indicated that the opposite was the case, with physical activity being positively correlated with good health and lack of physical activity being correlated with poor health.  

Contemporary studies have consistently demonstrated there is an inverse relationship between physical activity and cardiovascular death. Being fit is important for your cardiovascular health and this fitness is related to how much you do.

So how much physical activity is sufficient. And we look at who is most likely to benefit from physical activity it is the least fit in our community. One study quoted looked at a 40% reduction in death occurring between the least fit in the next least fit quartiles. It concluded that effort should be made to target the least fit people as slight increase in activity can as a community cause large improvements in our health status.

The optimal amount of physical activity has also been studied. Data from multiple studies have suggested there is a graded dose-response relationship between physical activity and fitness and mortality or disease states. In other words the fitter you are the healthier you will be. One study for example found that a low-volume activity group to exercise for only 90 minutes per week experienced a 14% risk of all-cause mortality and a three-year better life expectancy than those people who are inactive.

The Canadian physical activity guidelines indicated that the current requirement of at least 150 minutes of moderate to vigorous aerobic physical activity is associated with a 20 to 30% lower risk for premature all-cause mortality and incidence of chronic diseases.

Now looking at specific diseases.

1.       Cancer. This is the leading cause of death in the Western world accounting for approximately 30% of all deaths in Canada. A recent study confirmed the fitness is inversely related to cancer mortality with individuals with high cardiorespiratory fitness having a 45% reduced risk of total cancer mortality independent of adiposity. Physical activity seems to affect all stages of the cancer process is likely multiple mechanisms act together to reduce risk.

2.       Hypertension. This is the most common risk factor for stroke heart disease and kidney disease and is a leading cause of death. High-level physical activity is associated with decreased risk of developing hypertension.

3.       Diabetes. Type II diabetes is a significant problem. The strong evidence that risk factors which are modifiers that such as obesity and physical activity a domain non-genetic determinants of this disease. Treatment is difficult therefore prevention is recommended. In one study risk walking at least hundred 50 minutes per week when compared with the placebo reduce the incidence of diabetes by 58%.

4.       Stroke. In Kenneth/thirdly could cause of death. High levels of physical activity are associated with a 31% risk reduction in both men and women.

5.       Depression. This is associated with reduced quality of life and significant disability and usage of the healthcare system. It seems also to be independently associated with increased cardiovascular morbidity and mortality and is commonly seen in patients with coronary heart disease. Exercising patients with depression have shown you can increase depressive symptoms by up to 30%.

Conclusion

Physical inactivity is associated with many preventable chronic diseases. Becoming more physically active to the tune of 2 to 3 hours per week of moderate intensity exercise can significantly reduce your risk of cancer cardiovascula