Self-efficacy, neighborhood walking, and fall history in older adults.

This cross-sectional study examined the association of self-efficacy with neighborhood walking in older adult (mean age = 76.1, SD = 8.34) fallers (n = 108) and nonfallers (n = 217) while controlling for demographic characteristics and mobility. Hierarchical multiple regression indicated that the full model explained 39% of the variance in neighborhood walking in fallers (P < .001) and 24% in nonfallers (P < .001). Self-efficacy explained 23% of the variance in fallers (P < .001) and 11% in nonfallers (P < .001). Neighborhood walking was significantly associated with self-efficacy for individual barriers in both groups. Self-efficacy for neighborhood barriers trended toward significance in fallers (ß = .18, P = .06). Fall history did not moderate the relationship between self-efficacy and neighborhood walking. Walking interventions for older adults should address self-efficacy in overcoming individual walking barriers. Those targeting fallers should consider addressing self-efficacy for overcoming neighborhood barriers.

Effect of caffeine on LT, VT and HRVT.

UNLABELLED: Caffeine has many diverse physiological effects including central nervous system stimulation. Ventilatory threshold and a recently described heart rate variability threshold both have a relationship with autonomic control that could be altered by caffeine consumption. The purpose of this investigation was to determine the influence of caffeine on lactate, ventilatory, and heart rate variability thresholds during progressive exercise. Using a randomized placebo controlled, double-blind study design, 10 adults performed 2 graded maximal cycle ergometry tests with and without caffeine (5 mg·kg⁻¹). Respiratory gas exchange, blood lactate concentrations, and heart rate variability data were obtained at baseline and throughout exercise. RESULTS: At rest, caffeine (p<0.05) increased blood lactate, oxygen consumption, carbon dioxide production, and minute ventilation. For indices of heart rate variability at rest, caffeine increased (p<0.05) the coefficient of variation, while standard deviation, and mean successive difference displayed non-significant increases. During progressive exercise, minute ventilation volumes were higher in caffeine trials but no other parameters were significantly different compared to placebo tests. CONCLUSION: These data demonstrate the robustness of the lactate, ventilatory and heart rate variability thresholds when challenged by a physiological dose of caffeine.