As noted in this chapter, the \(\dot{V}_{\mathrm{O}_{2} \max }\) of people tends
to decline after age 30 by about \(9 \%\) per decade for sedentary individuals,
but it declines less than \(5 \%\) per decade for people who stay active. The
average \(\dot{V}_{\mathrm{O}_{2 \max }}\) in healthy 30 -year-olds is about
\(3.1 \mathrm{~L} / \mathrm{min}\). Using the information given here, what would
the average \(\dot{V}_{\mathrm{O}_{\text {max }}}\) be in 60 -year-olds who have
been sedentary throughout their lives and in 60 -year-olds who have stayed
active (keep in mind that the decline is exponential)? Consider the activities
in Table \(9.1\), and recall from Chapter 7 that \(1 \mathrm{~kJ}\) is equivalent
to about \(0.05 \mathrm{~L}\) of \(\mathrm{O}_{2}\) in aerobic catabolism. How
would you expect sedentary and active people to differ in their capacities for
each of those activities in old age? Explain.