The relationship of joint symptoms with exercise performance in older adults.

OBJECTIVES: The objective of this study is to determine if exercise increases joint symptoms in older adults with a history of arthritis or produces symptoms in older adults without such history. In addition, we examine whether joint symptoms explain the large observed variation in strength gain in older adults undergoing vigorous strength training exercise, and report the incidence of musculoskeletal injuries upon initiation of an exercise program. DESIGN: A population-based, single blinded, randomized controlled trial with three exercise groups and one control group. SETTING: A large urban health maintenance organization. PARTICIPANTS: Older men and women (N = 105) aged 68 to 85, with leg strength below the 50th percentile for their age, sex, height, and weight and without neuromuscular disease or active cardiovascular disease. INTERVENTIONS: Supervised exercise in 1-hour sessions, three times each week, for 24 to 26 weeks. One exercise group did strength training (ST) using weight machines (n = 25); another group did endurance training (ET) using stationary cycles (n = 25); and the third group did combined strength training and endurance training (ST+ET) (n = 25). The control group (n = 30) received no intervention. MEASUREMENTS: Strength was measured at the ankle, knee, hip, and elbow using an isokinetic dynamometer. Joint symptoms were rated on a 6-point scale (0 = none, 5 = severe). Arthritis severity was based on self-reported use of arthritis medication. Health status was measured with subscales of the SF-36 and Sickness Impact Profile (SIP). RESULTS: Joint symptoms fluctuated over time in all exercise groups, but they did not improve or worsen significantly in any group. The physical dimension of the SIP and SF-36 subscale scores, including Bodily Pain Scores, did not change over time in any group. Subjects with arthritis and joint symptoms gained as much strength with strength training as did subjects without joint symptoms. Adjustment for age, gender, baseline strength, adherence, and exercise group did not affect this finding. The rate of minor musculoskeletal injuries was 2.2 injuries per 1000 exercise hours. CONCLUSIONS: Moderate intensity stationary cycle exercise and vigorous intensity strength training do not appear to produce or exacerbate joint symptoms in older adults. Joint symptoms did not explain the large variation in gains in strength in older adults participating in a standardized strength training exercise program. Musculoskeletal injuries occurred relatively infrequently, and no major injuries occurred. In evaluating joint pain that occurs in older adults in well regulated exercise programs, clinicians should consider other etiologies before attributing pain to exercise per se.

The Seattle FICSIT/MoveIt study: the effect of exercise on gait and balance in older adults.

While exercise is generally recommended for older adults, the specific role of exercise in preventing falls and frail health is unclear. The Seattle FICSIT/MoveIt study is a population-based, randomized, controlled trial comparing the effects of three 6-month exercise interventions (endurance training, strength training, or combined endurance and strength training), and three 3-month endurance training interventions (stationary cycle, walking, or aerobic movement). Primary study outcomes are aerobic capacity, strength, gait, balance, and physical functional status. The study enrolls adults age 68-85 who have leg weakness and impaired gait. It differs from most previous community-based exercise studies in several respects: recruitment of subjects from a defined population; eligibility criteria based upon physiologic and functional status deficits; random assignment to exercise groups; assessment of both physiologic and functional status outcomes; follow-up beyond the completion of supervised exercise; and a large sample size (Total N = 180).

Relationship between physical performance and self-perceived physical function.

OBJECTIVE: The objective of this study was to compare two methods of measuring physical function in subjects with a broad range of abilities and to evaluate the effects of cognitive, social, educational, and age factors on the relationship between the two methods. DESIGN: Multiple regression analysis was used to compare self-perceived (dependent variables) with performance measures (independent variables). Covariates included age, gender, Mini-Mental State Exam score, education, living status, and depression score. SETTING: Five community-dwelling and two nursing home sites. PARTICIPANTS: 417 community-dwelling subjects and 200 nursing home residents aged 62-98 years. MEASUREMENTS: Self-perceived physical function was assessed with the physical dimension summary score of the Sickness Impact Profile, which comprises three subscales: ambulation, mobility, and body care and movement. Physical performance was evaluated by self-selected gait speed, chair-stand time, maximal grip strength, and a balance score. RESULTS: Nursing home residents and community-dwellers were significantly different (P < .0001) in all variables except age and gender. Self-perceived and performance-based measures were moderately correlated, with a range from r = -.194 to r = -.625 (P < .05). Gait speed was the strongest independent predictor of self-perceived physical function in both groups. Symptoms of depression were also an independent predictor of self-perceived function in nursing home residents; subjects who had such symptoms report more self-perceived dysfunction than would be predicted based on performance tests. CONCLUSIONS: Self-selected gait speed is a global indicator of self-perceived physical function over a broad range of abilities. External determinants (depressive symptoms, cognitive function, marital status, etc.) affect self-perceived function in both groups, but gait speed is the greatest single predictor of self-perceived function. In nursing home residents depressive symptomatology is related to self-perceived.

From muscle properties to human performance, using magnetic resonance.

Our goal is to show how muscle properties can be used to understand the exercise performance limitations of the elderly. We show that magnetic resonance (MR) imaging and spectroscopy are useful for noninvasively characterizing the structural and energetic properties of muscle in vivo. Determination of muscle volume and cross-sectional area is easily and rapidly accomplished by applying quantitative morphometric methods to MR images. New MR spectroscopic techniques provide a noninvasive "biopsy" of the oxidative, glycolytic, and contractile capacities of muscle fibers. We show how the structural and energetic properties measured by MR can be used to define the functional capacity of muscle and the contribution of this capacity to the performance of the whole body (e.g., VO2max). Finally, we relate these laboratory measures of muscle properties and performance to activities meaningful to the functioning of the elderly in everyday life, such as sustained walking and stair climbing.

The effect of strength and endurance training on gait, balance, fall risk, and health services use in community-living older adults.

BACKGROUND: The study tested the effect of strength and endurance training on gait, balance, physical health status, fall risk, and health services use in older adults. METHODS: The study was a single-blinded, randomized controlled trial with intention-to-treat analysis. Adults (n = 105) age 68-85 with at least mild deficits in strength and balance were selected from a random sample of enrollees in a health maintenance organization. The intervention was supervised exercise (1-h sessions, three per week, for 24-26 weeks), followed by self-supervised exercise. Exercise groups included strength training using weight machines (n = 25), endurance training using bicycles (n = 25), and strength and endurance training (n = 25). Study outcomes included gait tests, balance tests, physical health status measures, self-reported falls (up to 25 months of follow-up), and inpatient and outpatient use and costs. RESULTS: There were no effects of exercise on gait, balance, or physical health status. Exercise had a protective effect on risk of falling (relative hazard = .53, 95% CI = .30-.91). Between 7 and 18 months after randomization, control subjects had more outpatient clinic visits (p < .06) and were more likely to sustain hospital costs over $5000 (p < .05). CONCLUSIONS: Exercise may have beneficial effects on fall rates and health care use in some subgroups of older adults. In community-living adults with mainly mild impairments in gait, balance, and physical health status, short-term exercise may not have a restorative effect on these impairments.

Exercise: effects on physical functional performance in independent older adults.

BACKGROUND: Age-related loss in physiologic capacities contributes to the decline in physical function in the elderly population. Despite the beneficial effects of exercise interventions on maximal physiologic capacity measures, the functional benefits have not been shown in independently living older adults. The objective of this study was to evaluate exercise in independent older adults for significant and meaningful improvements in physical function, not detected by commonly used measures of physical function. METHODS: In a randomized controlled study, 49 independently living men and women were assigned to either a nonexercise control group (Control; n = 26) or an exercise training group (Exercise; n = 23). Participants (age = 76+/-4) in good general health were recruited from retirement communities or apartments. The combined endurance and strength training was performed at 75% to 80% intensity; the groups met 3 times/week for 6 months of supervised sessions. Outcome measures included physical capacity, health status, and physical function using a newly developed performance test--the Continuous Scale-Physical Functional Performance test (CS-PFP). RESULTS: Compared to the Control group, the Exercise group showed significant increases in maximal oxygen consumption (11%) and muscle strength (33%). No significant differences were found between groups for changes in the Sickness Impact Profile, SF-36 scales, or the 6-minute walk. However, the CS-PFP score improved significantly in the Exercise group (14%, effect size 0.80). CONCLUSIONS: Independent older adults gain meaningful functional benefits from several months of exercise training. The public health importance of physical activity may relate not just to its role in preventing decline, but also to its role in enhancing physical function.

Factors associated with changes in gait speed in older adults.

BACKGROUND: The study addressed whether changes in gait speed in community-dwelling older adults were associated with changes in fitness (strength and aerobic capacity), physical health status, and/or depressive symptoms. METHODS: The study sample comprised 152 community-dwelling adults aged 68-85 who had participated in an exercise study. Study measures at baseline and 6-month follow-up included gait speed, a leg strength score, maximal aerobic capacity (VO2max), CES-Depression scale, and physical health status (SIP Physical Dimension). RESULTS: In cross-sectional regression analyses, leg strength, VO2max, weight, and the strength by VO2max interaction term were significant independent predictors of gait speed (R2 = 26%). Based upon the observed 7% increase in VO2max and 8% increase in strength in the exercise groups, the regression model predicted only a 2% (1.5 m/min) increase in gait speed, which did not differ significantly from the observed increase of 0% (.32 m/min). The strongest correlate of change in gait speed was change in CES-D scores (partial R = -.37). Change in physical health status also correlated with change in gait speed (partial R = -.28), while change in fitness did not. CONCLUSIONS: The results suggest, in the range of fitness of the study sample, that changes in gait speed are related to changes in depressive symptoms and physical health status, but not to modest changes in fitness. A model assuming nonlinear relationships may be appropriate for understanding how strength and aerobic capacity affect gait speed.

Large energetic adaptations of elderly muscle to resistance and endurance training.

This study determined the cellular energetic and structural adaptations of elderly muscle to exercise training. Forty male and female subjects (69.2 +/- 0.6 yr) were assigned to a control group or 6 mo of endurance (ET) or resistance training (RT). We used magnetic resonance spectroscopy and imaging to characterize energetic properties and size of the quadriceps femoris muscle. The phosphocreatine and pH changes during exercise yielded the muscle oxidative properties, glycolytic ATP synthesis, and contractile ATP demand. Muscle biopsies taken from the same site as the magnetic resonance measurements were used to determine myosin heavy chain isoforms, metabolite concentrations, and mitochondrial volume densities. The ET group showed changes in all energetic pathways: oxidative capacity (+31%), contractile ATP demand (-21%), and glycolytic ATP supply (-56%). The RT group had a large increase in oxidative capacity (57%). Only the RT group exhibited change in structural properties: a rise in mitochondrial volume density (31%) and muscle size (10%). These results demonstrate large energetic, but smaller structural, adaptations by elderly muscle with exercise training. The rise in oxidative properties with both ET and RT suggests that the aerobic pathway is particularly sensitive to exercise training in elderly muscle. Thus elderly muscle remains adaptable to chronic exercise, with large energetic changes accompanying both ET and RT.

Changing affordances in stair climbing: the perception of maximum climbability in young and older adults.

This experiment extended Warren's leg-length model by investigating the relevance of leg strength and joint flexibility on perceptual judgments of climbability. From a set of 8 stairs (riser heights: 38-91 cm), 24 older and 24 young adults were asked to identify the highest stair they could climb without using their hands or knees. Ss then attempted to climb the selected stair. Tall and short young observers perceived similar action boundaries despite leg-length differences. Tall and short older adults had divergent action boundaries when a single-scale leg-length model was applied. A regression model that used flexibility and leg-strength measurements provided a better fit of the older adult data, indicating that models applying functional (kinematic and kinetic) criteria might be useful in describing lawful relationships between organisms and the environment.

Effect of training on VO2max, thigh strength, and muscle morphology in septuagenarian women.

The purpose of this study was to determine the effects of a long-term (50 wk) combined aerobic-resistance training program on maximal oxygen consumption (VO2max, thigh strength, and vastus lateralis fiber morphology in healthy septuagenarian women (mean age = 72 +/- 6 yr). Subjects volunteered to be in either an exercise (Ex; N = 17) or control (Con; N = 10) group. Con subjects were 34% less active in winter than in summer, Ex subjects maintained their summer activity level on exercise days in winter. Initial, intermediate (20 wk), and final (50 wk) measurements were made for isokinetic knee extension/flexion strength; VO2max and morphological measurements from a muscle biopsy were made at the initial and final times only. Both groups gained in leg strength (Ex = +6.5%; Con = +7.8%; P less than or equal to 0.05) during the summer; in the winter the Ex group maintained leg strength and the Con group declined 12.2% (P less than or equal to 0.05). The fast-twitch muscle fiber area (Type IIb) increased 29% (P less than or equal to 0.001) in the Ex group and declined 26% (P = 0.014) in the Con group. VO2max increased only in the Ex group (16%; P less than 0.001). We conclude that healthy septuagenarian women can increase aerobic capacity, leg strength, and Type IIb muscle fiber area with a long-duration, combined aerobic-resistance exercise program.

Isokinetic strength testing in older women: a comparison of two systems.

FUNDING: National Institute of Aging; University of Wisconsin Graduate School. Isokinetic equipment is used for measuring muscular strength for both experimental and rehabilitative purposes. In this study two LIDO(R) isokinetic dynamometer systems, the LIDO-digital and the LIDO-active, were compared at 60, 180, 240, and 300 degrees /see for peak torque (PT) and average work output (WO) of knee flexion and extension. Twenty-five elderly women (age range = 65-86) were tested on both systems within seven days. The data were compared by using a repeated measures ANOVA followed by a Dunn-Bonferroni posthoc comparison (p

Functional training: muscle structure, function, and performance in older women.

Response to physical training at the cellular and whole muscle level has been established in older adults. However, the underlying molecular mechanism responsible for change has not been described nor have the relationships between change in muscle structure and functional performance been established. The purpose of this research study is to evaluate the changes of muscle ultrastructure, muscle strength, and whole body functional performance as a result of a functionally directed exercise program (stair climbing). Women (65-83 years old) selected either the control (no exercise; N = 6) or exercise (N = 7) group. The 1-year functionally based exercise program was both aerobic (75% heart rate reserve) and resistive (weighted stair climbing). Muscle ultrastructure, determined by quantitative morphometry of the vastus lateralis tissue, and maximal step-height achieved by each subject were related to isokinetic strength and muscle morphology. Changes in myofibrillar area accounted for 48% of the variance in muscle strength changes. Change in muscle contractile protein was the underlying basis for change in thigh strength which, in turn, was the basis for functional performance. These data provide evidence that, in older women, a mild functionally based training program results in improved muscle structure and performance of the lower body.

A lifetime of fitness. Exercise in the perimenopausal and postmenopausal woman.

The peri- and postmenopausal woman experiences physiologic changes of aging that include alterations in hormone levels. Research has shown that the perimenopausal and postmenopausal woman can benefit significantly from exercise, whether endurance or strength training. Exercise can improve the quality of life and attenuate some of the physiologic changes associated with aging. Additionally, exercise can ameliorate the decline in fitness and bone, prevent chronic disease, and promote functional independence. Women who exercise regularly throughout life are physiologically 20 to 30 years younger than their sedentary counterparts. Fitness is a lifetime endeavor that has many positive benefits. Weightbearing activities are especially important as bone loss increases in the perimenopausal phase of life. Women should perform aerobic exercise 3 to 7 days per week for 15 to 60 minutes at 65% to 70% HRreserve. Strengthening exercises should be done 2 to 3 days per week at 40% to 80% 1RM with appropriately selected exercises. An exercise program should be functional and enjoyable. There is no better motivation to exercise than having a partner to work out with and keep the motivation alive. Most important, age itself is not a deterrent to exercise.

Continuous-scale physical functional performance in healthy older adults: a validation study.

OBJECTIVE: The continuous-scale physical functional performance test (CS-PFP) is an original instrument designed to provide a comprehensive, in-depth measure of physical function that reflects abilities in several separate physical domains. It is based on a concept of physical function as the integration of physiological capacity, physical performance, and psychosocial factors. SETTING: The test was administered under standard conditions in a hospital facility with a neighborhood setting. The CS-PFP consists of a battery of 15 everyday tasks, ranging from easy to demanding, that sample the physical domains of upper and lower body strength, upper body flexibility, balance and coordination, and endurance. Participants are told to work safely but at maximal effort, and physical functional performance was measured as weight, time, or distance. Scores were standardized and scaled 0 to 12. The test yields a total score and separate physical domain scores. DESIGN: The CS-PFP was evaluated using 148 older adults-78 community dwellers, 31 long-term care facility residents living independently, and 39 residents with some dependence. MAIN OUTCOME MEASURES: Maximal physical performance assessment included measures of maximal oxygen consumption (VO2max), isokinetic strength, range of motion, gait, and balance. Psychosocial factors were measured as self-defined health status using the Sickness Impact Profile (SIP), self-perceived function using the Health Survey (SF36), and Instrumental Activities of Daily Living (IADL). RESULTS: IADL scores were not significantly different among the groups. Test-retest correlations ranged from .84 to .97 and inter-rater reliability from .92 to .99 for the CS-PFP total and 5 domains. Internal consistency was high (Cronbach's alpha, .74 to .97). Both total and individual domain CS-PFP scores were significantly different for the three groups of study participants, increasing with higher levels of independence, supporting construct validity. CS-PFP domain scores were significantly correlated with measures of maximal physical performance (VO2max, strength, etc) and with physical but not emotional aspects of self-perceived function. CONCLUSION: The CS-PFP is a valid, reliable measure of physical function, applicable to a wide range of functional levels, and having minimal floor and ceiling effect. The total and physical domains may be used to evaluate, discriminate, and predict physical functional performance for both research and clinical purposes.

Isokinetic testing of ankle strength in older adults: assessment of inter-rater reliability and stability of strength over six months.

The study purposes were (1) to estimate the inter-rater reliability of isokinetic strength tests at the ankle in older adults (test-retest interval of three to 7 days), and to determine whether more experienced examiners were more reliable; and (2) to estimate 6 month stability of strength tests. Inter-rater reliability was high for plantar flexion and dorsiflexion tests where average strength was more than about 10 Newton-meters (Nm) (Pearson R = 0.87-0.95). When average strength was less than 10Nm, reliability was less (R = 0.42-0.75). Experienced examiners (physical therapists) and less experienced examiners (research assistants) were equally reliable. Variability in strength over 6 months was no greater than variability over a few days. We conclude that isokinetic tests of ankle strength in older adults are highly reliable and stable when examiners are adequately trained and subjects maintain usual physical activity levels.

A comparison of the effects of three types of endurance training on balance and other fall risk factors in older adults.

We hypothesized that short-term endurance training improves balance in older adults, if training involves movements that "stress" balance. We tested the hypothesis by looking for a dose-response relationship between movement during exercise and balance improvement. The study was a single-blinded, randomized controlled trial. Subjects were sedentary adults (N = 106) aged 68-85 with at least mild deficits in balance. Exercise groups were: stationary cycle (low movement), walking (medium movement), and aerobic movement (high movement). Subjects attended supervised exercise classes three times a week for three months, followed by self-directed exercise of any type for three months. The primary test of the hypothesis compared changes in balance after three months of supervised exercise. One balance measure (distance walked on a six-meter narrow balance beam) improved in the hypothesized dose-response manner (cycle, 3% improvement; walking, 7% improvement; aerobic movement, 18% improvement: p < 0.02, test of trend). Other balance measures did not improve with exercise. Only walking exercise improved gait speed (by 5%, p < 0.02) and SF-36 role-physical score (by 24%, p < 0.05). VO2max improved with walking (18%, p < 0.004) and aerobic movement (10%, p < 0.01), but improved less with cycling (8%, p > 0.1). Leg strength improved significantly in all exercise groups. The study hypothesis was supported only for one balance measure. Only walking improved at least one measure of all major outcomes (endurance, strength, gait, balance, and health status), suggesting that walking is most useful for all prevention. Cycle exercise appeared least useful.

Ageing, muscle properties and maximal O(2) uptake rate in humans.

This paper asks how the decline in maximal O(2) uptake rate (VO(2),max) with age is related to the properties of a key muscle group involved in physical activity - the quadriceps muscles. Maximal oxygen consumption on a cycle ergometer was examined in nine adult (mean age 38.8 years) and 39 elderly subjects (mean age 68.8 years) and compared with the oxidative capacity and volume of the quadriceps. VO(2),max declined with age between 25 and 80 years and the increment in oxygen consumption from unloaded cycling to VO(2),max (delta VO(2)) in the elderly was 45 % of the adult value. The cross-sectional areas of the primary muscles involved in cycling - the hamstrings, gluteus maximus and quadriceps - were all lower in the elderly group. The quadriceps volume was reduced in the elderly to 67 % of the adult value. Oxidative capacity per quadriceps volume was reduced to 53 % of the adult value. The product of oxidative capacity and muscle volume - the quadriceps oxidative capacity - was 36 % of the adult value in the elderly. Quadriceps oxidative capacity was linearly correlated with delta VO(2) among the subjects with the slope indicating that the quadriceps represented 36 % of the VO(2) increase during cycling. The decline in quadriceps oxidative capacity with age resulted from reductions in both muscle volume and oxidative capacity per volume in the elderly and appears to be an important determinant of the age-related reduction in delta VO(2) and VO(2),max found in this study.