Table 2.

Physical Fitness and Physical Functioning Measures^a

Variable	n	Mean (SD)
Peak $\stackrel{.}{\mathrm{V}}{\mathrm{O}}_2$ (mL/kg/min)	42	16.5 (3.1)
Peak MET	44	6.3 (1.2)
Peak RPE	44	15.3 (2.1)
Peak RER	40	1.07 (0.06)
Peak heart rate (beats per minute)	44	115 (17)
Double product (mm Hg·bpm)	44	20 498 (4693)
SPPB score	44	10.0 (2.3)
SPPB balance	44	3.6 (0.69)
SPPB gait speed	44	3.6 (0.65)
SPPB chair rise	44	2.8 (1.3)
ISWT (m)	43	257 (124)
6-MWD (m)	43	381 (105)

Abbreviations: peak $\stackrel{.}{\mathrm{V}}{\mathrm{O}}_2$, peak oxygen consumption; ISWT, incremental shuttle walk test; 6 MWD, 6-min walk distance; Peak MET, peak metabolic equivalent (1 MET = 3.5 mL/kg/min in oxygen consumption and is considered a measure of multiples of resting energy expenditure); RER, respiratory exchange ratio (ratio of carbon dioxide produced/exhaled and oxygen used); RPE, rating of perceived exertion (6-20, higher is more exertion); SD, standard deviation; SPPB, Short Physical Performance Battery (0-12, higher score = better physical function); SPPB balance score, 0-4, higher is better balance; SPPB chair rise score, 0-4, higher is better; SPPB gait speed score, 0-4, higher is better gait speed.

^aSee text for the commonly reported age-appropriate normative values.