[Physical activity and health--recommendations].
BACKGROUND
The health consequences of physical inactivity and the health gains of regular physical activity are briefly summarized. We present physical activity recommendations based on a review of the literature for the general adult population.


METHODS
This report employs recognised international standards for establishing causal relationships between physical activity and disease, distinguishing between four different levels: Convincing, probable, possible and insufficient evidence. Convincing or probable evidence have provided the basis for the recommendations given.


RESULTS
The total amount of physical activity (a combination of intensity, duration and frequency) is related to a number of health variables in a dose-response relationship. The preventive effect (the health gain) increases with increasing activity level, but the relationship is not linear. The greatest health gains are attained by those who are least physically fit. This applies even in old age. The health gain seems primarily to be dependent on the total energy expenditure, and less on the intensity. The dose-response relationship between physical activity levels and health gains is a continuum that does not seem to have a lower limit. Thus, any activity can be said to be better than none.


CONCLUSIONS
We conclude that a minimum "target dose" that will yield substantial health gains for those who have been physically inactive for a long time, is activity of moderate intensity which corresponds to an energy expenditure of approximately 150 kcal (630 kJ) per day (or slightly more than 1,000 kcal (4.2 MJ) per week). This is equivalent to a daily walk of about 30 minutes. The activity can be divided into shorter intervals of physical activity during the course of the day, for instance intervals lasting 5-10 minutes. An increase in activity beyond this level will yield further health gains. The effect of exercise is just as good for older people as for younger people, and the same recommendations apply as to other adults.
Anderssen
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Ullevål sykehus 0407 Oslo. sigmunda@nih.no
Strømme
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SB
D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D018849:Controlled Clinical Trials as Topic; D004734:Energy Metabolism; D019317:Evidence-Based Medicine; D015444:Exercise; D017408:Guidelines as Topic; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D010809:Physical Fitness