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Background. This study explored the associations between various types of activities, their underlying physical components, and recurrent falling in community-dwelling older persons. Methods. This study included 1,329 community-dwelling persons ([greater than or equal to]65 years) of the Longitudinal Aging Study Amsterdam (LASA). The time spent in walking, cycling, light and heavy household activities, and two sports was measured using the LASA Physical Activity Questionnaire (LAPAQ). Physical activity components included strength, intensity, mechanical strain, and turning. Time to second fall in a 6-month period was measured during 3 years with fall calendars. Cox proportional hazards models were adjusted for confounders and stratified for physical performance and sex in case of significant (p < .10) interaction. Results. During 3 years, 325 (24.5%) persons became recurrent fallers. In women, doing light (hazard ratios [HRs] = 0.40, 95% confidence intervals [CIs] = 0.20-0.79) or heavy household activities (HR = 0.63, CI = 0.44-0.79) was associated with a decreased risk of recurrent falling. In persons with good physical performance, doing sports (HR = 1.56, CI = 1.07-2.28), high intensity (HR > 1.75, CI = 1.09-3.16), and high mechanical strain (HR = 1.70, CI = 1.01-2.83) activities was associated with an increased risk of recurrent falling. Conclusions. The results suggest that the relationship between physical activity and recurrent falling differs per type of activity and is modified by physical performance. Doing household activities was associated with a decreased risk of recurrent falling in women. In physically fit older persons, doing sports or activities with high intensity or mechanical strain demands was associated with an increased risk of recurrent falling. Key Words: Physical activity--Physical performance--Accidental falls--Aged. doi: 10.1093/gerona/glq013

J Strength Cond Res 24(1): 251-256, 2010--Reportedly, muscle fatigue in older individuals is greater, less than, or similar to young individuals, potentially because of differences in muscle groups studied, type of contraction, continuous vs. intermittent contractions, exercise duration, duty cycle, and contraction speed. During a single set of isokinetic mode knee extensions, muscle fatigue is similar between older and younger individuals. However, repeated sets may favor the more oxidative nature of muscle from older adults and may be necessary to reveal age-associated enhanced fatigue resistance. The purpose of this investigation was to compare muscular fatigue induced by repeated sets of intermittent isokinetic mode knee extensions in older and younger males. Nineteen older (mean [+ or -] SD) (66 [+ or -] 6 yr) and 16 younger (21 [+ or -] 2 yr) men completed 5 sets of 30 isokinetic mode knee extensions at 180 degrees/second. In the analysis of absolute fatigue, both groups significantly decreased torque production during each set, with young men having significantly higher torque production during all 5 sets. Relative fatigue was significantly greater in young participants during sets 2 through 5 (old vs. young: set 2:1 7.1 vs. 26.6%; set 3:25.5 vs. 39.7%; set 4:28.1 vs. 45.1%; set 5:29.3 vs. 46.4%; overall relative fatigue: old 22.2%; young 38.1%). These data indicate enhanced fatigue resistance in older men, which was revealed using repeated sets of intermittent contractions. Resistance to muscle fatigue is only one component of healthy aging muscle, and perhaps exercise interventions targeted toward prevention of falls in the elderly should focus on improved muscle power rather than fatigability/sustainability of contractions. KEY WORDS sarcopenia, muscle endurance, elderly, isokinetic, aging, exercise, Biodex

Background. Aging is associated with a decline in exercise capacity that may be attributable to maladaptations in both skeletal muscle perfusion and metabolism; yet very little is known regarding the real-time, within-muscle interplay between these parameters during physical activity. Therefore, we utilized an unique nuclear magnetic resonance sequence to concomitantly examine changes in lower leg skeletal muscle perfusion and metabolism. Methods. In young (26 [+ or -] 5 years, n = 6) and older (70 [+ or -] 5 years, n = 6) healthy volunteers, arterial spin labeling measurements of muscle perfusion were combined with 31 Phosphorous ([sup.31]P) nuclear magnetic resonance spectroscopy to monitor high-energy phosphate metabolites during and after 5 minutes of moderate-intensity ([approximately equal to]5W) plantar flexion exercise. Results. Compared with young, end-exercise perfusion was diminished in older participants (43 [+ or -] 10 mL/100 g/minute, old, 60 [+ or -] 7 mL/100 g x minute, young), accompanied by greater phosphocreatine (PCr) depletion (-28% [+ or -] 12%, old; -19% [+ or -] 7%, young) and elevated inorganic phosphate/PCr (0.41 [+ or -] 0.2, old: 0.24 [+ or -] 0.09, young); yet the time constant for PCr recovery ([tau], an index of muscle oxidative capacity) was similar between groups (51 [+ or -] 17 seconds, old; 48 [+ or -] 7 seconds, young). Conclusions. Together, these preliminary data provide evidence of an age-related decline in tissue perfusion and increased 'metabolic stress' during exercise but demonstrate that overall oxidative capacity in the elderly does not appear negatively affected by this relatively hypoperfused state. Key Words: [sup.31]P spectroscopy--Oxidative capacity--Exercise--Aging.

Objectives. The present study of a representative sample of older adults quantified everyday physical activity (EPA) by having participants wear actigraphs. Our objectives were to examine whether poor health may partly explain why older adults become less physically active with advancing age and whether gender might moderate the extent to which health status predicts EPA. Methods. We performed multiple regression analyses on a sample of older, community-dwelling adults (aged 80-98 years, N = 198; women = 63.1%). Results. The results imply that age-related declines in EPA may be partially accounted for by health (in men) and by living arrangements (in women). Discussion. We consider reasons why poorer health might erode EPA for men (but not women) and why living alone might erode EPA for women (but not men). Key Words: Activity--Actigraph--Gender--Health--Living arrangements.

We examined the hypothesis that physical activity will have favorable effects on measures of self-efficacy for a 400-m walk and satisfaction with physical functioning in older adults 70+ years of age who have deficits in mobility. We randomized a total of 412 adults aged 70-89 years at elevated risk for mobility disability to either a physical activity or a successful aging educational control intervention for 12 months. Participants in the physical activity intervention had more favorable changes in both outcomes as a result of treatment than those in the successful aging intervention. Gender, age, and scores on a short physical performance battery did not moderate these effects. Physical activity is an effective means of intervening on self-efficacy and satisfaction with physical function in older adults with impaired lower extremity functioning. This is an important finding in light of the importance of these process variables in behavior change and quality of life. Key Words: Self-efficacy--Aging--Disability--Mobility--Quality of life.

Background. Reactive oxygen species production increases during aging, whereas protective mechanisms such as heat shock proteins (HSPs) or antioxidant capacity are depressed. Physical activity has been hypothesized to provide protection against oxidative damage during aging, but results remain controversial. This study aimed to investigate the effect of different levels of physical activity during aging on Hsp72 expression and systemic oxidative stress at rest and in response to maximal exercise. Methods. Plasma antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC), thiobarbituric acid-reactive species (TBARS), advanced oxidized proteins products (AOPP), and Hsp72 expression in leukocytes were measured before and after maximal exercise testing in 32 elderly persons (aged 73.2 years), who were assigned to two different groups depending on their level of physical activity during the past 12 months (OLow = moderate to low level; OHigh = higher level). Results. The OHigh group showed higher aerobic fitness and TEAC (both representing 120% of OLow values) as well as lower oxidative damage (50% of OLow values) and Hsp72 expression. Exercise led to a lower increase in oxidative +damage in the OHigh group. Aerobic fitness was positively correlated with TEAC and negatively with lipid peroxidation (TBARS). Hsp72 expression was negatively correlated with TEAC but positively correlated with TBARS levels. Conclusions. The key finding of this study is that, in people aged 60 to 90 years, long-term high level of physical activity preserved antioxidant capacity and limited oxidative damage accumulation. It also downregulated Hsp72 expression, an adaptation potentially resulting from lower levels of oxidative damage.

The physical benefits of a functional exercise circuit are not well known in an elderly population. The purpose of this study was to evaluate the effect of a functional exercise circuit on mobility and perceived health in the elderly. Subjects were 119 men and women (aged 74 [[+ or -] 4.2] years) who received pre-and posttests of mobility (e.g., sit to stand, get up and go, timed walk), flexibility (sit and reach), and balance (standing reach) and who completed the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). A supervised functional exercise circuit that included 10 different upper- and lower-body exercises performed under time constraints was performed 3 times per week for 12 consecutive weeks. Paired t-tests showed significant differences at posttest for the get up and go (p < 0.001), standing reach (p < 0.001), sit and reach (p < 0.001), and selected items from the SF-36, including physical functioning (p < 0.001), pain (p = 0.001), vitality (p = 0.001), and number of doctor visits (p < 0.001). A functional exercise circuit such as the one employed in this study may offer promise as an effective means of promoting mobility and perceived health in older adults. Key Words. enhanced mobility, perceived health

The purpose of this study was to characterize the mechanical demands of the lower-extremity musculature during the standing forward lunge (FL) and the standing lateral lunge (LL) exercises performed by older adults. Twenty healthy older adults (9 men, 11 women, mean age 75.0 [+ or -] 4.4 years) performed FL and LL while instrumented for biomechanieal analysis. Lower-extremity net joint moments, powers, impulse, and mechanical energy expenditure were determined using standard inverse dynamics techniques. The FL preferentially targeted the hip extensors, producing a greater flexion angle (12.8%), peak joint moment (13.6%), joint power (56.5%), and mechanical energy expenditure (25.1%). Conversely, LL targeted the ankle plantar flexors, producing greater dorsiflexion angles (19.3%), joint moments (40.9%), impulse (87.0%), and mechanical energy expenditure (61.1%). Kinetic differences at the knee were less consistent. Fitness professionals may use this information to better match the biomechanical attributes of FL and LL activities with the needs of the trainee. KEY WORDS. strength training, functional exercise, mechanical energy expenditure, impulse

Sar-co-PEE-nee-ah. It starts to set in around age 45, when muscle mass begins to decline at a rate of about 1 percent per year. This gradual loss has been tied [...]