Abstract

Principal component analysis was used to estimate the physical fitness age (PFA) of middle-aged and elderly men from 8 physical fitness variables. Subjects were 184 Japanese men (20-75 yr), recruited in a series of physical fitness tests including oxygen uptake corresponding to lactate threshold (VO2 alpha LT) and VO2max. The subjects were categorized into three groups: those (n=134) considered apparently healthy, those (n=35) employed as a cross-validation sample, and 15 patients with coronary heart disease (CHD). The equation developed for estimation of PFA in healthy individuals (n=134) was PFA = -15.3 PFS + 48.0+Z, PFS = 0.021X1 + 0.0037X2 + 0.020X3 + 0.024X4 + 0.017X5 + 0.017X6 + 0.008X7 + 0.016X8 - 4.92, Z = 0.12 Age - 5.8; where PFS = physical fitness score, X1 = VO2max (ml/kg/min), X2 = VO2 alpha LT (ml/kg/min), X3 = grip strength (kg), X4 = side step (reps/20s), X5 = trunk extension (cm), X6 = trunk flexion (cm), X7 = foot balance with eyes closed (s), and X8 = vertical jump (cm). Analyses of the data revealed that healthy individuals had PFAs (47.7+/-17.5 yr) similar to their chronological ages (CA: 48.0+/-15.3 yr). In the cross-validation sample, it was confirmed that no difference existed between PFA (51.5+/-13.8 yr) and CA (52.1+/-11.8 yr). CHD patients, however, had PFAs approximately 15 years older than their CAs (57.7+/-11.5 vs. 72.2+/-12.3 yr). Since independent variables of the above equation consisted of various physical fitness elements, we defined the score as an index of physical fitness age. Verf.-Referat