The relative utility of health-related fitness tests and skilled motor performance tests as measures of biological age in Japanese men.

Abstract

In the present paper we report the results of a study in which we compared 2 different approaches to the computation of biological age (BA) in a sample of 322 Japanese men (age range 20 to 79 years). In the first approach, 4 commonly used measures of health-related fitness (VO2peak, trunk flexion from a standing position, body fat, and grip strength) were reduced to a single BA score (HRF Age) using principal component analysis. In contrast, in the second approach, 3 commonly used measures of skilled motor performance and agility (vertical jump, stepping side-to-side, and balancing on one leg with eyes closed) were reduced to a single BA score (SMP Age) using similar multivariate procedures. The criterion-related validity of both of the BA measures was examined by assessing each measure's ability to discriminate between healthy and active groups of subjects. This was achieved by classifying the original subject pool into regularly active (ACT; n = 108) and healthy (HLTH; n = 169) subgroups on the basis of self-reported activity levels. Analyses revealed that HRF Age was a more powerful discriminator between the two activity groups than SMP Age. While HRF Age of HLTH subjects was very close to their chronological age (CA), in the ACT group, HRF Age was on average 15 years less than their CA (P < 0.05). In a separate analysis, we assessed the HRF Age of patients with ischemic heart disease, hypertension, obesity, or diabetes (PAT; n = 45). The HRF Age of these subjects averaged 10 years above their CA. Our data suggest that commonly used measures of health-related fitness can be usefully employed as indices of BA which differentiate between individuals of similar ages but differing health and physical activity status. In contrast, measures of skilled motor performance were found to be less valuable measures of BA. The implication of our findings for future experimental design in exercise and aging research is discussed.