Physiological fitness measures and sensory and motor performance in aging

This study investigated relationships between a multivariate index of physiological fitness and the degree of age-related sensory and motor performance deterioration observed in a group of 70 male subjects (age 63 +/- 12 years). Physiological fitness was determined by reducing a battery of resting pulmonary, hemodynamic and biochemical variables to a single score, the Index of Physiological Status (IPS). In addition, where possible, maximal oxygen uptake (VO2max) was predicted from submaximal values using a standard treadmill procedure. Both IPS and VO2 scores were significantly correlated with age (p less than .01). High scores on the IPS were associated with faster reaction times, improved hearing at high frequencies, greater phonatory control and improved lens accommodation. In contrast, VO2 measures were found to be insensitive to changes in sensory and motor performance. While all subjects were able to complete the tests required for the generation of the IPS, 33% of the participants were unable to complete the treadmill protocol required for estimation of VO2max. These data suggest that a simple noninvasive instrument for the evaluation of physiological fitness, which is applicable to almost all elderly subjects, may be more sensitive to age-related sensory and performance changes than more traditional exercise based measures which require the exclusion of less healthy subjects.