Purpose. Evaluate the effects of weight loss on muscle mass and area, muscle fat infiltration, strength, and their association with physical function. Methods. Thirty-six overweight to moderately obese, sedentary older adults were randomized into either a physical activity plus weight loss (PA+WL) or physical activity plus successful aging health education (PA+SA) program. Measurements included body composition by dual-energy X-ray absorptiometry, computerized tomography, knee extensor strength, and short physical performance battery (SPPB). Results. At 6 months, PA+WL lost greater thigh fat and muscle area compared to PA+SA. PA+WL lost 12.4% strength; PA+SA lost 1.0%. Muscle fat infiltration decreased significantly in PA+WL and PA+SA. Thigh fat area decreased 6-fold in comparison to lean area in PA+WL. Change in total SPPB score was strongly inversely correlated with change in fat but not with change in lean or strength. Conclusion. Weight loss resulted in additional improvements in function over exercise alone, primarily due to loss of body fat.

Previous research has demonstrated that muscular strength of the knee extensors is related to the speed an athlete can produce during a single-sprint performance. Football players, as well as many other athletes on the field and the court, execute multiple sprints during the course of a match. The purpose of this study was to examine the relationships between leg strength, single-sprint speed, and repeated-sprint ability. Thirty-eight football players from 3 codes (soccer, rugby league, rugby union) completed a 12- x 20-m repeated-sprint protocol and were evaluated for peak isokinetic knee extension and flexion torque at 60 degrees .s(-1), 150 degrees .s(-1), and 240 degrees .s(-1). Although single-sprint performance correlated with peak extensor and flexor torque at all velocities, the strongest correlation was observed between relative knee extensor torque at 240 degrees .s(-1) and the initial acceleration phase (0-10 m) of the single-sprint performance (r = -0.714, p < 0.01). However, the data suggest that factors other than strength contribute to repeated-sprint ability. This finding provides new evidence in elucidating the relationship between strength and repeated-sprint performance.

Background: Animal models of exercise and Parkinson's disease (PD) have found that the physiologic use of exercise may interact with the neurodegenerative disease process, likely mediated by brain derived neurotrophic factor (BDNF). No reviews so far have assessed the methodologic quality of available intervention studies or have bundled the effect sizes of individual studies on exercise-induced effects on BDNF blood levels in human PD. Research design and methods: We searched MEDLINE, EMBASE, Cochrane Library, PsycINFO and PubMed from inception to June 2017.

The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase III randomized controlled clinical trial (Clinicaltrials.gov identifier: NCT01072500) that will provide definitive evidence regarding the effect of physical activity (PA) on major mobility disability in older adults (70–89 years old) who have compromised physical function. This paper describes the methods employed in the delivery of the LIFE Study PA intervention, providing insight into how we promoted adherence and monitored the fidelity of treatment. Data are presented on participants’ motives and self-perceptions at the onset of the trial along with accelerometry data on patterns of PA during exercise training. Prior to the onset of training, 31.4% of participants noted slight conflict with being able to meet the demands of the program and 6.4% indicated that the degree of conflict would be moderate. Accelerometry data collected during PA training revealed that the average intensity – 1,555 counts/minute for men and 1,237 counts/minute for women – was well below the cutoff point used to classify exercise as being of moderate intensity or higher for adults. Also, a sizable subgroup required one or more rest stops. These data illustrate that it is not feasible to have a single exercise prescription for older adults with compromised function. Moreover, the concept of what constitutes “moderate” exercise or an appropriate volume of work is dictated by the physical capacities of each individual and the level of comfort/stability in actually executing a specific prescription.

INTRODUCTION Month-to-month variation in physical activity levels in a cohort of post-menopausal women participating in a single site clinical trial undergoing lifestyle intervention was investigated prior to and after lifestyle intervention. METHODS Participants were Caucasian and African-American women (mean age 57.0 ± 3.0) from the Women On the Move through Activity and Nutrition (WOMAN) study. Physical activity was measured subjectively by questionnaire and objectively by pedometer at baseline and at the 18-month follow-up. RESULTS At baseline, prior to intervention, pedometer steps were highest in the summer months (7,616 steps/day), lower in the fall (6,293 steps/day), lowest in winter (5,304 steps/day), and then rebounded in the spring (5,850 steps/day). Physical activity estimates from the past-week subjective measure followed the same seasonal pattern. After 18-months, the lifestyle change group significantly increased their pedometer step counts when compared to the health education group (p<0.0001). At 18-months, pedometer step counts for the health education group followed a pattern similar to that found in the entire group prior to intervention, whereas, month-to-month step counts for the lifestyle change group appeared to remain consistent throughout the year. CONCLUSIONS These results confirm previous reports that suggest physical activity levels fluctuate throughout the year. Lifestyle intervention, which includes a physical activity component, not only increases step counts, but appears to reduce some of variation in physical activity levels over the course of a year in post-menopausal women.

BackgroundData are sparse regarding the value of physical activity (PA) surveillance among older adults—particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study.Methods and ResultsCardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home‐based activity data were collected by hip‐worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84–0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65–0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow‐up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85–0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63–0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates.ConclusionsObjective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data.Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500.

Objective To evaluate the extent of variability in functional responses among participants in the LIFE study, and to identify the relative contributions of intervention adherence, physical activity, and demographic and health characteristics to this variability. Design Secondary analysis of the Lifestyle Interventions and Independence for Elders (LIFE) study. Setting Multicenter U.S. institutions participating in the LIFE study. Participants A volunteer sample of 1635 sedentary men and women aged 70 to 89 years who were able to walk 400 m, but had physical limitations, defined as a score on the Short Physical Performance Battery (SPPB) of ≤9. Interventions Moderate-intensity physical activity (PA, n=818) consisting of aerobic, resistance and flexibility exercises performed both center-based (twice/wk) and in or around the home environment (3-4 times/wk) or health education (HE, n=817) consisting of weekly to monthly workshops covering relevant health information. Main Outcome Measures Physical function: gait speed over 400-m and lower extremity function (SPPB) assessed at baseline, six, twelve, and 24 months. Results Greater baseline physical function (gait speed and SPPB score) was inversely associated with Δ gait speed (regression coefficient β=−0.185, p<0.001) and ΔSPPB score (β=−0.365, p<0.001), while greater number of steps per day measured by accelerometry was positively associated with Δ gait speed (β=0.035, p<0.001) and Δ SPPB score (β=0.525, p<0.001). Other baseline factors associated with positive Δ gait speed and/or SPPB score include younger age (p<0.001), lower body mass index (p<0.001), and higher self-reported physical activity (p=0.002). Conclusions Several demographic and physical activity-related factors were associated with the extent of Δ functional outcomes among participants in the LIFE study. These factors should be considered when designing interventions for improving physical function among older adults with limited mobility.

Objective To determine which of four proposed risk scores best predicts immediate outcome of cardiac surgery. Design Observational cohort study. Setting Sir Charles Gairdner Hospital (a university teaching hospital), Perth, Western Australia, 18 March 1993 to 5 March 1996. Subjects 927 consecutive patients undergoing surgery for coronary artery disease. Outcome measures Patient risk scores (by methods of Parsonnet et al., Higgins et al., Tremblay et al. and Tu et al.); in‐hospital mortality; postoperative hospital stay >14 days; receiver operating characteristic (ROC) curves comparing sensitivity and specificity in predicting adverse outcomes for each risk score. Results In‐hospital mortality rate was 3.5% and mean postoperative hospital stay was 10.7 days. The four scores had similar predictive abilities, with mean areas under the ROC curves (95% confidence intervals) for mortality and postoperative stay >14 days, respectively: 0.70 (0.62‐0.78) and 0.70 (0.65‐0.75) for the Parsonnet score; 0.68 (0.59‐0.77) and 0.70 (0.64‐0.75) for the Higgins score; 0.68 (0.59‐0.77) and 0.67 (0.62‐0.73) for the Tremblay score; and 0.68 (0.60‐0.76) and 0.69 (0.64‐0.75) for the Tu score. Conclusion Any of the scores may be used to estimate perioperative risk and to compare outcome between coronary surgery units, but none has sufficient specificity and sensitivity to identify specific individuals who will experience an adverse outcome. Further development of risk assessment is needed before adverse outcome can be accurately predicted in cardiac surgical patients.