Physical activity, benefits

Activity is thought to play a role in obesity, but studies designed to test the benefit of increased physical activity yield inconsistent results. 

R T is one form of vigorous physical activity, and as such may share the benefits for muscle strength and metabolic capacity which probably selected for such general forms of play in most mammalian species. However, this does not explain the more specialised forms of vigorous play which constitute R T, nor its social nature. 

Movement is an essential component of life. If something moves, it is assumed to be alive. External movement depends upon skeletal muscle whereas internal movement depends upon smooth and cardiac muscles. The latter muscles are discussed in other chapters. The term physical activity is another term for external movement. Hence, it depends on skeletal muscle. This chapter contains a discussion of the biochemistry of skeletal muscle, including its involvement in everyday activities. This leads into the biochemistry underlying both the benefits and hazards of physical activity. In addition, the biochemical bases of the common problem of fatigue and the debilitating condition of chronic fatigue are discussed. 

In comparison, physical activity may not have the same "catch-up" capacity. The case has been made that exercise when yoimg is likely to provide lifelong benefits to bone structure and strength (Warden et al, 2007). It is possible that comparisons of "catch-up" with diet and physical activity are not yet possible until we have comparable ranges of deficiency and timing of deficiency prior to a period of adequacy. To generalize from the Matkovic study, dietary Ca intakes in the United States in placebo arms of randomized controlled trials are only moderately deficient compared to the very low Ca intakes of children in certain regions of Oriental (Lee et al, 1993, 1995) and Third World coimtries (Dibba et al, 2000), for example, who consume little or no milk. 

I could cite chapter and verse from the scientific literature to try to make a convincing argument for the health benefits of exercise. Just lifting the many volumes of books and journals would be a lot of exercise in itself. I ll spare you the details, but here are some of the benefits of regular physical activity. 

How much is enough Again, to see improvements in blood pressure, you d need to take a moderate to brisk walk for thirty minutes or so only three times a week. To achieve weight loss or to maintain your weight, increase that to five or six days weekly. To gain the most benefit for your health in general and your heart in particular, your goal would be to walk about fourteen miles a week or the equivalent in another physical activity. 

For most people, greater health benefits can be obtained by engaging in physical activity of more vigorous intensity or longer duration. 

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