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Background: The aim of this study is to investigate whether combined cognitive and physical training provides additional benefits to fall prevention when compared with physical training (PT) alone in older adults.Methods: This is a prespecified secondary analysis of a single-blind, randomized controlled trial involving community-dwelling men and women aged 70-85 years who did not meet the physical activity guidelines. The participants were randomized into combined physical and cognitive training (PTCT, n = 155) and PT (n = 159) groups. PT included supervised and home-based physical exercises following the physical activity recommendations. PTCT included PT and computer-based cognitive training. The outcome was the rate of falls over the 12-month intervention (PTCT, n = 151 and PT, n = 155) and 12-month postintervention follow-up (PTCT, n = 143 and PT, n = 148). Falls were ascertained from monthly diaries. Exploratory outcomes included the rate of injurious falls, faller/recurrent faller/fall-related fracture status, and concern about falling.Results: Estimated incidence rates of falls per person-year were 0.8 (95% confidence interval [CI] 0.7-1.1) in the PTCT and 1.1 (95% CI 0.9-1.3) in the PT during the intervention and 0.8 (95% CI 0.7-1.0) versus 1.0 (95% CI 0.8-1.1), respectively, during the postintervention follow-up. There was no significant difference in the rate of falls during the intervention (incidence rate ratio [IRR] = 0.78; 95% CI 0.56-1.10, p = .152) or in the follow-up (IRR = 0.83; 95% CI 0.59-1.15, p = .263). No significant between-group differences were observed in any exploratory outcomes.Conclusion: A yearlong PTCT intervention did not result in a significantly lower rate of falls or concern about falling than PT alone in older community-dwelling adults.Clinical Trial Registration: ISRCTN52388040. [ABSTRACT FROM AUTHOR]

Progressive strength training can lead to substantial increases in maximal strength and mass of trained muscles, even in older women and men, but little information is available about the effects of strength training on functional capabilities and balance. Thus, the effects of 21 weeks of heavy resistance training--including lower loads performed with high movement velocities--twice a week on isometric maximal force (ISOmax) and force-time curve (force produced in 500 milliseconds, F0-500) and dynamic 1 repetition maximum (1RM) strength of the leg extensors, 10-m walking time (10WALK) and dynamic balance test (DYN.D) were investigated in 26 middle-aged (MI; 52.8 [+ or -] 2.4 years) and 22 older women (O; 63.8 [+ or -] 3.8 years). 1RM, ISOmax, and F0-500 increased significantly in MI by 28 [+ or -] 10%, 20 [+ or -] 19%, 31 [+ or -] 34%, and in O by 27 [+ or -] 8%, 20 [+ or -] 16%, 18 [+ or -]+ 45%, respectively. 10WALK (MI and O, p < 0.001) shortened and DYN.D improved (MI and O, p < 0.001). The present strength-training protocol led to large increases in maximal and explosive strength characteristics of leg extensors and in walking speed, as well to an improvement in the present dynamic balance test performance in both age groups. Although training-induced increase in explosive strength is an important factor for aging women, there are other factors that contribute to improvements in dynamic balance capacity. This study indicates that total body heavy resistance training, including explosive dynamic training, may be applied in rehabilitation or preventive exercise protocols in aging women to improve dynamic balance capabilities. KEY WORDS. resistance training, maximal and force-time characteristics, performance

Background. Among older people, fracture-causing fall often leads to health deterioration. The role of endogenous hormone status and muscle strength on fall-related fracture risk is unclear. This study investigates if, after adjustment for bone density, endogenous hormones and muscle strength would predict fall-related limb fracture incidence in older community-dwelling women followed-up over 10 years. Methods. As a part of a prospective population-based study, 187 75-year-old women were investigated. Serum estradiol, testosterone, sex hormone binding globulin, and dehydroepiandrosterone sulfate concentrations were analyzed, and isometric muscle strength and bone mineral density were assessed. Fall-related limb fractures were gathered from patient records. Results. Serum estradiol concentration was a significant predictor of fall-related limb fractures. Women with serum estradiol concentrations less than 0.022 nmol/L had a 3-fold risk (relative risk 3.05; 95% confidence interval, 1.26-7.36), and women with estradiol concentrations between 0.022 and 0.066 nmol/L doubled the risk (relative risk 2.24; 95% confidence interval, 0.97-5.19) of fall-related limb fracture compared to the women with estradiol concentrations above 0.066 nmol/L. Adjustment for muscle strength and bone mineral density did not materially change the risk estimates. High muscle strength was associated with a low incidence of fall-related limb fractures. Conclusions. This study showed that in 75-year-old women higher serum estradiol concentration and greater muscle strength were independently associated with a low incidence of fall-related limb fractures even after adjustment for bone density. Our results suggest that hormonal status and muscle strength have their own separate mechanisms protecting from fall-related fractures. This finding is of importance in developing preventive strategies, but calls for further study.

Background. Among older people, distraction while walking may increase the risk of falls. Factors underlying individual differences in dual tasking are not fully understood. Our aim was to study the effect of a second task on maximal walking speed and to examine whether individual differences in walking speed measured with and without a second task are accounted for by genetic and environmental influences shared across tasks or specific to each task. Methods. The data were collected from the 101 monozygotic and 116 dizygotic twin pairs aged 63-76 years recruited from the Finnish Twin Cohort. Maximal walking speed (MWS) over 10 m was measured on a laboratory corridor and timed with photocells. The test was repeated while subjects performed, first, a manual task (MWSmanual) and, second, a verbal task (MWSverbal). Results. Mean walking speed without a simultaneous task was 1.72 m/s (standard deviation [SD] 0.33), with a manual task it was 1.52 m/s (SD 0.26), and with a verbal task it was 1.36 m/s (SD 0.27). Multivariate genetic analysis showed that an additive genetic factor in common accounted for 17% of individual differences in MWS, 19% in MWSmanual, and 12% in MWSverbal. In addition, MWSverbal had a genetic factor specific to it accounting for 10% of the variance. Shared environmental influences, common to all three traits, accounted for 39%, 27%, and 21% of the individual differences, respectively. Conclusion. Approximately half of the individual differences in walking with or without another task were accounted for by genetic and nongenetic familial effects in common, and the rest of the variation was accounted for by unique environmental factors in common and factors specific to walking tests.

Acute and long-term hormonal and neuromuscular adaptations to hypertrophic strength training were studied in 13 recreationally strength-trained men. The experimental design comprised a 6-month hypertrophic strength-training period including 2 separate 3-month training periods with the crossover design, a training protocol of short rest (SR, 2 minutes) as compared with long rest (LR, 5 minutes) between the sets. Basal hormonal concentrations of serum total testosterone (T), free testosterone (FT), and cortisol (C), maximal isometric strength of the leg extensors, right leg 1 repetition maximum (1RM), dietary analysis, and muscle cross-sectional area (CSA) of the quadriceps femoris by magnetic resonance imaging (MRI) were measured at months 0, 3, and 6. The 2 hypertrophic training protocols used in training for the leg extensors (leg presses and squats with 10RM sets) were also examined in the laboratory conditions at months 0, 3, and 6. The exercise protocols were similar with regard to the total volume of work (loads x sets x reps), but differed with regard to the intensity and the length of rest between the sets (higher intensity and longer rest of 5 minutes vs. somewhat lower intensity but shorter rest of 2 minutes). Before and immediately after the protocols, maximal isometric force and electromyographic (EMG) activity of the leg extensors were measured and blood samples were drawn for determination of serum T, FT, C, and growth hormone (GH) concentrations and blood lactate. Both protocols before the experimental training period (month 0) led to large acute increases (p < 0.05-0.001) in serum T, FT, C , and GH concentrations, as well as to large acute decreases (p < 0.05-0.001) in maximal isometric force and EMG activity. However, no significant differences were observed between the protocols. Significant increases of 7% in maximal isometric force, 16% in the right leg 1RM, and 4% in the muscle CSA of the quadriceps femoris were observed during the 6-month strength-training period. However, both 3-month training periods performed with either the longer or the shorter rest periods between the sets resulted in similar gains in muscle mass and strength. No statistically significant changes were observed in basal hormone concentrations or in the profiles of acute hormonal responses during the entire 6-month experimental training period. The present study indicated that, within typical hypertrophic strength-training protocols used in the present study, the length of the recovery times between the sets (2 vs. 5 minutes) did not have an influence on the magnitude of acute hormonal and neuromuscular responses or long-term training adaptations in muscle strength and mass in previously strength-trained men. Key Words. serum hormones, resistance exercise, muscle strength, electromyography, cross sectional area, dietary intake