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Exercise and Physical Activity
Exercise, it turns out, may not be effective in controlling your weight after all! The reason is that exercise - 'compartmentalised' physical activity - is only effective if it is done in addition to, rather than in place of, your regular physical activity. This is not always the case.
In a research study in America, a group of older adults took part in a 12 week graded exercise program to examine the effects of exercise on fitness, resting metabolic rate and total energy expenditure.
After 12 weeks the participants were fitter on a measure of endurance capacity. They had also increased their resting metabolic rate, or the amount of calories burned at rest. Surprisingly, however, there was no change in total energy expenditure as measured by the 'gold standard' of measures. The participants, it turns out, had spontaneously reduced the amount of incidental physical activity - activity done during the normal course of daily activities - in anticipation of their exercise sessions.
It was this loss of incidental activity that meant that there was no change in overall energy expenditure, and therefore no subsequent loss of weight.
Managing your weight is a not so simply balancing act of calories in and calories out. A few weekly bouts of exercise at your local gym results in small increases in overall energy expenditure, which over time, will assist in weight control only if there is no corresponding reduction in background, or incidental activity.
So by all means get to the gym and do your exercise. It will make you fitter and healthier. It will also help you control your weight, but only if you don't take your exercise sessions as an opportunity to take the rest of the day off! Keep on walking.
Article by Professor Kerry Mummery
Central Queensland University
