Table 1.

Subject characteristics

	Young Exercisers (n = 10)	Lifelong Exercisers (n = 7)	Old Healthy Nonexercisers (n = 10)
Age, yr	25 ± 1	72 ± 2	75 ± 1
Height, cm	167 ± 2	164 ± 2	157 ± 2
Weight, kg	60 ± 2	61 ± 4	65 ± 1
BMI, kg/m2	21 ± 1	23 ± 1	27 ± 1*
Body fat, %	23 ± 1*	30 ± 2†	41 ± 2
V̇o2max, mL·kg−1·min−1	44 ± 2*	26 ± 2†	18 ± 1
Quadriceps CSA, cm2	59 ± 2*	42 ± 2	40 ± 1
Quadriceps strength, Nm	138 ± 10†	105 ± 9	82 ± 4
Quadriceps 1RM, kg	80 ± 6*	54 ± 4	42 ± 2
Quadriceps power, W	404 ± 38*	221 ± 20	146 ± 10
Steps per day	11,518 ± 1,404*	7,463 ± 683	6,801 ± 823

Values are means ± SE. BMI, body mass index; CSA, cross-sectional area; 1RM, 1-repetition maximum; V̇o_2max, maximal oxygen consumption.

^*P < 0.05 vs. other groups;

^†P < 0.05 vs. OH.