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Cardiorespiratory fitness is widely recognized as a major component of overall p

ID: 3431221 • Letter: C

Question

Cardiorespiratory fitness is widely recognized as a major component of overall physical well-being. Direct measurement of maximal oxygen uptake (VO2max) is the single best measure of such fitness, but direct measurement is time-consuming and expensive. It is therefore desirable to have a prediction equation for VO2max in terms of easily obtained quantities. Consider the variables

y = VO2max (L/min)
x1 = weight (kg)
x2 = age (yr)
x3 = time necessary to walk 1 mile (min)
x4 = heart rate at the end of the walk (beats/min)

Here is one possible model for male students, consistent with the information given in the article "Validation of the Rockport Fitness Walking Test in College Males and Females"

Explanation / Answer

(a).Holding all other variables constant, a 1 kg increase in weight will result in a 0.01 L/min increase in VO2max.

Holding all other variables constant, a 1 min increase in walk time will result in a 0.13 L/min decrease in VO2max.

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(b)5.0 + 0.01*76 ? 0.05*24 ? 0.13*15 ? 0.01*138 = 1.23