We tested the hypothesis that the intensity of daily ambulation would relate with functional walking capacity in older adults. Forty-three women (n = 25) and men (n = 18) between the ages of 60-78 years wore an accelerometer for measurement of average daily steps and 30-min peak stepping cadence. A 400-m walk test was used to measure walking speed. No sex difference was found for average daily steps (p = .76), average peak cadence (p = .96), or walking speed (p = .89). Daily steps (women: r = .68, p < .01; men: r = .04) and peak cadence (women: r = .81, p < .01; men: r = −.16) were positively correlated with walking speed in women but not in men. After controlling for daily steps, peak cadence remained significantly associated with walking speed in women (partial r = .61, p < .01). Walking intensity during daily ambulation is independently related to functional walking capacity in older adults, albeit this relation may be more significant for women than men.
Joaquin U. Gonzales, Jordan Shephard and Neha Dubey
Youngdeok Kim, Joaquin U. Gonzales and P. Hemachandra Reddy
The purpose of this study was to examine short-term longitudinal relationships between handgrip strength (HGS) and cardiovascular disease (CVD) biomarkers in middle-aged to older adults living in rural areas (N = 138). The association between HGS and CVD biomarkers was examined at baseline, with HGS as a predictor of the annual change in biomarkers, and in a parallel fashion between the annual change in HGS and CVD biomarkers over an average of 2.8 follow-up years. The results showed HGS to cross-sectionally associate with waist circumference and diastolic blood pressure at baseline, but HGS at baseline was not found to predict the annual change in any biomarker. The annual increase in HGS was significantly associated with favorable changes in high-density lipoprotein cholesterol, triglycerides, and systolic/diastolic blood pressures; yet, these associations varied by the baseline levels of biomarkers. The present findings suggest that improved muscle strength with aging is related to favorable changes in CVD biomarkers.
Joaquin U. Gonzales, Dustin M. Grinnell, Martha J. Kalasky and David N. Proctor
The authors examined interindividual and sex-specific variation in systolic (SBP) and diastolic (DBP) blood pressure responses to graded leg-extension exercise in healthy older (60–78 yr) women (n = 21) and men (n = 19). Maximal oxygen uptake (VO2max), body composition, physical activity (accelerometry), and vascular function were measured to identify predictors of exercise BP. Neither VO2max nor activity counts were associated with the rise in SBP or DBP during exercise in men. The strongest predictors of these responses in men were age (SBP: r 2 = .19, p = .05) and peak exercise leg vasodilation (DBP: r 2 = –.21, p < .05). In women, the modest relationship observed between VO2max and exercise BP was abolished after adjusting for central adiposity and activity counts (best predictors, cumulative r 2 = .53, p < .05, for both SBP and DBP). These results suggest that determinants of variation in submaximal exercise BP responses among older adults are sex specific, with daily physical activity influencing these responses in women but not men.