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Relative Intensity of Activity for Younger and Fit Persons 
and for Older and Unfit Persons
Relative Intensity
Younger and Fit 
(12 MET capacity)
Older and Unfit 
(5 MET capacity)
Light
<3.2 METs
<1.8 METs
Moderate
3.2-7.5 METs
1.8-3.3 METs
Vigorous
≥
7.6 METs
≥
3.4 METs
SOURCE: Adapted from Table D-1 in PAGAC, 2008.
panel reported beneficial effects of regular physical activity on muscular 
health, cardiovascular health, adiposity, blood pressure, blood lipid levels, 
self-concept, anxiety, depressive symptoms, and academic performance. 
The optimal dose was more difficult to determine for at least two reasons 
(see also Box 2-2). First, different health outcomes accrue from different 
doses. Second, research demonstrates a positive dose response rather an 
ideal dose. The panel concluded, however, that “school-aged youth should