Cardiovascular stress associated with concentric and eccentric isokinetic exercise in young and older adults

Heart rate (HR), mean arterial blood pressure (MAP), and rate-pressure product (RPP) responses to submaximal isokinetic concentric (CON) and eccentric (ECC) knee extension exercise were compared at the same absolute torque output in 20 young (mean+/-SD=23.2+/-1.7 years) and 20 older (mean+/-SD=75.2+/-4.6 years) adults. After determination of peak CON and ECC torques, subjects performed separate, randomly ordered, 2-minute bouts of isokinetic CON and ECC exercise (90 degrees/s, exercise intensity: 50% of CON peak torque). CON exercise elicited greater changes in HR, MAP, and RPP than ECC exercise (p<.001) for both age groups. There were no age-related differences in HR, MAP, or RPP responses for either CON or ECC exercise. At the same absolute torque output, isokinetic CON knee extension exercise elicited significantly greater increases in cardiovascular stress than ECC exercise in both young and older adults. This result has implications for determining appropriate fitness and rehabilitation programs.     

Muscle power of the ankle flexors predicts functional performance in community-dwelling older women

OBJECTIVES: To test the hypothesis that peak power of the ankle flexors is related to physical functioning in older women with functional limitations. DESIGN: A cross-sectional study. SETTING: University-based human physiology laboratory. PARTICIPANTS: Thirty-four older women (75.4 +/- 5.1 years, 67.8 +/- 11.3 kg, body mass index 27.4 +/- 4.5) with self-reported functional limitations. MEASUREMENTS: Plantarflexion (PF) and dorsiflexion (DF) peak power and isometric strength with physical performance (stair climb time, repeated chair rise time, maximal and habitual gait velocity) were determined. An isokinetic dynamometer was used to measure isometric strength, isokinetic peak torque and power of PF and DF at five angular velocities (30 degrees, 60 degrees, 90 degrees, 120 degrees, and 180 degrees.sec-1), and isometric strength. RESULTS: Peak torque for both PF and DF declined with increasing velocity of movement (PF: P <.0001; DF: P <.0001), whereas peak power increased with increasing velocity up to 120 degrees.sec-1. The strongest univariate associations were found between chair rise time and DF peak power (r = 0.50; P <.002), stair climb time and DF peak power (r = 0.49; P <.003), habitual gait velocity and PF isometric strength (r = 0.53; P <.001), and maximal gait and PF isometric strength (r = 0.47; P <.005). Multivariate regression analysis revealed that DF and PF peak power along with the physical functioning and general health scores from the Medical Outcomes Study Short Form were independent predictors of chair and stair climb performance. CONCLUSION: These data suggest that ankle muscle power together with self-reported measures of health and physical functioning are essential components of functional mobility in older women with functional limitations.     

Biodex等速系统测试老年人膝关节屈伸肌力可靠性的初步研究

目的确定Biodex等速系统测试老年人膝关节伸肌和屈肌等速向心肌肉功能的可靠性。方法使用Biodex System 3型多关节等速系统在2个测试日对20名老年人（年龄71±6岁）的双下肢进行等速向心肌力测试。结果除了屈肌的作功疲劳度值,伸肌和屈肌两次测试的峰力矩、单次最大作功和平均功率值差异均有统计学意义（P〉0．05）。伸肌和屈肌两次重复测试的相关系数在0．40～0．96之间,除屈肌的作功疲劳度值的P值〉O．05,其余各指标的P值均〈0．05,具有相关关系。结论采用Biodex等速系统对老年人膝关节伸肌和屈肌进行的肌肉功能的重复测试之间具有较好的可靠性。同时提示,有必要加强测试程序的标准化、测试前的热身和熟练程序。     

Changes in isokinetic torque and muscular activity of elbow flexors muscles with age

This study examined the influence of aging on torque–angular velocity relationships for elbow flexion and the corresponding muscular activity levels in order to target the mechanisms involved in the eccentric muscle action in older adults. Maximal constant angular torque (CAT) at 90° was measured at different angular velocities for concentric (CON; 60, 120, 180, 240° s⁻¹), isometric (ISO) and eccentric (ECC; −60, −120° s⁻¹) elbow flexor muscle actions in older (OG; 6 females and 4 males, 64–82 years) and young adult subjects (YG; 6 females, 6 males, 19–24 years) on an isokinetic dynamometer. Myoelectrical activity was quantified on biceps and triceps muscles, using the root mean square (RMS) procedure over a range of 30° motion (75–105°). Absolute CAT was significantly greater (p<0.04) for YG in comparison with OG for all types of actions (CON, ECC, ISO). The only effect of gender concerned absolute strength values (p=0.00007). However, the OG showed higher (p<0.001) relative CAT values (expressed as percentage of CON 60° s⁻¹ value) during ECC muscle action than the YG. Nevertheless, RMS values for elbow flexors were significantly (p<0.03) lower in the OG than in the YG. The antagonist (triceps) co-activation was similar for both groups. The relative ECC force preservation with aging seems to be independent of a muscular activation phenomenon.     

Heavy resistance training increases muscle size, strength and physical function in elderly male COPD-patients--a pilot study

This study investigated the effects of heavy resistance training in elderly males with chronic obstructive pulmonary disease (COPD). 18 Home-dwelling male patients (age range: 65-80 years), with a mean forced expiratory volume in the first second (FEV1) of 46 +/- 3.4% of predicted value, were recruited. Baseline and post-training assessments included: Cross-sectional area (CSA) of quadriceps assessed by MRI, isometric and isokinetic knee extension strength, isometric trunk strength, leg extension power, normal and maximal gait-speed on a 30 m track, stair climbing time, number of chair stands in 30 s, lung function (FEV1) and self-reported health. Subjects were randomized to a resistance training group (RE, n = 9) or a control group conducting breathing exercises (CON, n = 9). RE performed heavy progressive resistance training twice a week for 12 weeks. 6 RE and 7 CON completed the study. In RE the following improved (P < 0.05): Quadriceps CSA: 4%, isometric knee extension strength: 14%, isokinetic knee extension strength at 60 degrees /s.: 18%, leg extension power: 19%, maximal gait speed: 14%, stair climbing time: 17%, isometric trunk flexion: 5% and self-reported health. In CON no changes were found. In conclusion, 12 weeks of heavy resistance training twice a week resulted in significant improvements in muscle size, knee extension strength, leg extension power, functional performance and self-reported health in elderly male COPD patients.     

Older men are more fatigable than young when matched for maximal power and knee extension angular velocity is unconstrained

The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque–power relationships were constructed prior to and following both fatiguing tasks and during short-term recovery. Contractile properties were recorded from 9 old (~75 years) and 11 young (~25 years) men during three testing sessions. In the first session, maximal power was assessed, and sessions 2 and 3 involved an isokinetic or an isotonic concentric fatigue task performed until maximal power was reduced by 40 %. Compared with young, the older men performed the same number of contractions to task failure for the isokinetic task (~45 contractions), but 20 % fewer for the isotonic task (p < 0.05). Regardless of age and task, maximal voluntary isometric contraction strength, angular velocity, and power were reduced by ~30, ~13, and ~25 %, respectively, immediately following task failure, and only isometric torque was not recovered fully by 10 min. In conclusion, older men are more fatigable than the young when performing a repetitive maximal dynamic task at a relative resistance (isotonic) but not an absolute velocity (isokinetic), corresponding to maximal power.     

Age-related differences in knee muscle strength in normal women

This study provides normal baselines of knee muscle strength for women up to 86 years of age. Knee muscle strength (torque) was measured during maximum isometric and dynamic (isokinetic) contractions in 72 normal healthy women in three age groups between 20 and 86 years. Strength of the oldest group ranged from 56 to 78% of that in the youngest group, depending on knee joint position. Strength values were greater for isometric contractions than for isokinetic contractions (performed at 36 degrees per second) and were approximately twice as great for the extensor as for the flexor muscles. For both muscle groups, the torque generated with the knee in 30 degrees of flexion was usually lower than that generated with the knee at the 45- or 60-degree position. Despite the significant deficit found in the strength of the oldest group, it is likely that this relative weakness would not be detected on routine clinical examination using manual muscle testing.     

Effects of maximal isometric and isokinetic resistance training on strength and functional mobility in older adults

BACKGROUND: The aim of the present study was to compare the changes in voluntary strength (isometric, concentric, and eccentric) and functional mobility in response to maximal isokinetic eccentric-only resistance training to those elicited by maximal isometric-only or maximal isokinetic concentric-only resistance training in older adults. METHODS: Twelve women (73 +/- 7 years) and 18 men (73 +/- 5 years) completed a 12-week training program (three times per week) using a Biodex System 3 dynamometer. Primary outcome measures included peak isometric and isokinetic (concentric and eccentric) knee extensor strength, concentric work, concentric power, stair ascent and descent, and gait speed. Participants were randomly assigned to one of three training groups: isometric-only, isokinetic concentric-only, or isokinetic eccentric-only. RESULTS: All three training groups demonstrated an increase in peak isometric and isokinetic concentric and eccentric strength following 12 weeks of training (p <.01). Step time was positively influenced (p <.03) by all three training modes; however, gait speed was unchanged following 12 weeks of training. All three training groups experienced a significant increase in peak concentric work and concentric power (p <.01) with the concentric training group demonstrating the largest increases in both peak concentric work and concentric power when compared to the isometric and eccentric training groups. CONCLUSIONS: It was clear that all three resistance training programs (isometric, concentric, and eccentric) in older adults were effective in increasing strength, concentric work, and concentric power over the 12-week training period. Furthermore, 12 weeks of resistance training resulted in improved stair ascent and descent performance.     

Assessment of extensor and flexor strength in the individual gonarthrotic patient: Interpretation of performance changes

Summary The intra-session and inter-session reproducibility of knee extensor and flexor strength measurements were examined in 21 gonarthrotic subjects (ten women and eleven men). Using the Cybex 6000 dynamometer, isokinetic peak torque and total work at 30 and 120 degrees/second and isometric peak torque were measured three times on separate days within two weeks by the same examiner. The reproducibility of walking and stair climbing time measurements was also assessed. The concept of critical difference (i.e. the difference between two measurements which would be statistically significant when applied to a reference group in steady state) for the interpretation of muscle strength data obtained by monitoring individual patients is presented.Individual coefficients of variation (CV) were calculated for each muscle strength variable. Depending on the velocity and on whether peak torque or total work were measured, the median CV of intra-session and inter-session extensor strength measurements ranged from 1.5–4.9% and 7.4–10.1%, respectively. CVs for flexor strength measurements were significantly higher. Substantial variability of within subject variances were found, e.g. the 80% central range of CVs for extensor toruqe at 30 degrees/second was 2.5–29.5% (inter-session). Calculated from CVs, critical differences for inter-session measurements exceeded 30% for all muscle strength variables. Median CVs for walking and stair-climbing time were 7.0% and 4.9%, respectively.In conclusion, the large CVs and corresponding critical differences may be a major limitation in the use of muscle strength measurements in the individual gonarthrotic patient.     

Effects of eccentric training on torque-angular velocity-power characteristics of elbow flexor muscles in older women

The purpose of this study was to investigate the potential of eccentric training to improve elbow flexor muscle power in elderly subjects. Fourteen older female volunteers (age range 60-78 years) were randomly assigned into either a training group (TG) or a control group (CG). For the TG, the 21-session 7-week eccentric training program consisted of 5x6 eccentric muscle actions at 60-100% of concentric three maximal repetitions. Before and after training, maximal elbow flexions were performed against increasing inertia. Maximal isokinetic elbow flexions at four angular velocities (eccentric actions, -60 degrees s(-1), -30 degrees rads(-1); concentric actions, 30, 60 degrees s(-1)) and maximal isometric actions were also performed. Maximal power (Pmax) and an index of maximal shortening velocity (VImax)were determined. For all action conditions, the myoelectric activities of the biceps and the triceps brachii muscles were recorded and quantified as a root mean square (RMS) value. In the TG, maximal torque developed under isometric, isokinetic and inertial conditions increased significantly after training (ranging from 11 to 19%). Pmax and VImax also increased significantly (31.3 and 25.9%, respectively). These parameters remained unchanged in the CG. The RMS activity of the biceps and triceps muscles was not affected by eccentric training for all action conditions excepting the eccentric condition at -30 degrees s(-1) where the RMS activity of the biceps increased significantly. The gains in maximal torque, Pmax and VImax observed after training would result more from intramuscular modifications than from changes in muscular activity, except for eccentric condition at -30 degrees s(-1) where the torque gains could also be partly explained by a reduction in inhibition of the motor unit pool.     

Neuromechanical properties of the triceps surae in young and older adults

The aim of this study was to compare voluntary and involuntary force generating capacity of the triceps surae muscles in healthy young and older adult participants during isometric and isokinetic contractions. Ultrasound was used to measure medial gastrocnemius (MG) fascicle length during maximal voluntary isometric contractions and supra-maximal isometric twitch contractions at five ankle angles throughout the available range of motion, as well as isokinetic concentric and eccentric contractions at four ankle velocities. Maximum voluntary activation of the plantar flexors was assessed using the twitch interpolation technique. Peak plantar flexor torque was significantly lower in older adults compared to young participants by 42%, 28% and 43% during maximal voluntary isometric contractions, supra-maximal isometric twitch and concentric contractions respectively. No age-related differences in eccentric torque production were detected. When age-related differences in triceps surae muscle volume determined from MRI were taken into account, the age-related peak plantar flexor torque deficits for maximum voluntary isometric, supra-maximal twitch, and concentric contractions were 24%, 19% and 24% respectively. These age-related differences in torque were not explained by torque–length–velocity behaviour of the MG muscle fascicles, passive plantar flexor torque–angle properties, decreased neural drive of the plantar flexor muscles or antagonistic co-activation of the tibialis anterior muscle. The residual deficit in isometric and concentric plantar flexor torques in healthy older adults may involve reduced muscle quality. A significant reduction in supra-maximal twitch torque at longer MG fascicle lengths as well as a lower MG fascicle velocity during eccentric contractions in older adults was detected, which could possibly be a function of the reported increased Achilles tendon compliance in older adults.     

Isometric and isokinetic quadriceps strength in gonarthrosis; Inter-relations between quadriceps strength,walking ability,radiology, subchondral bone density and pain

Summary Patients with osteoarthrosis suffer from disability and pain. We measured isokinetic and isometric peak torque in 20 women with gonarthrosis (GA) and in 26 healthy controls. Relationships between muscle strength, walking and stair climbing time, pain level and pain disability scores as assessed by the patients using an extensive questionnaire, radiological changes and subchondral sclerosis expressed as bone mineral density (BMD, g/cm²) of the proximal tibia were studied.Precision errors of the torque measurements in both GA patients and controls were approximately 6%. In the GA patients, isokinetic and isometric quadriceps strength was reduced by 40 and 15% (p<0.01) respectively, and walking and stair climbing time was increased by 30% (p<0.005). Isokinetic strength was a better predictor of pain level and pain disability scores than isometric strength and radiological stage. Walking time and stair climbing time were not associated with quadriceps strength, pain level, pain disability scores or radiological changes. Subchondral BMD was not predictive of pain.The study suggests that quadriceps strength assessed by isokinetic dynamometry in GA is a reliable measurement. Isokinetic strength was pronouncedly reduced compared to isometric strength and was a more important predictor of pain and pain disability than isometric strength. These findings should be taken into consideration when planning exercise studies and programmes in GA.     

Echo intensity is associated with skeletal muscle power and cardiovascular performance in elderly men

The purpose of the present study was to investigate the relationship between echo intensity, neuromuscular and cardiorespiratory performances in the elderly. Thirty-one healthy elderly men (65.5±5.0) participated in this study. Echo intensity of rectus femoris and quadriceps femoris muscle thicknesses was determined by ultrasound images. Lower-body isometric and isokinetic peak torques (60, 180 and 360°(.s-1)), as well as rate of force development were evaluated as strength parameters. In addition, torque per unit of muscle mass was evaluated by the quotient between isometric peak torque of the knee extensors and the quadriceps femoris muscle thickness. The peak oxygen uptake (VO(2peak)), maximum aerobic workload (W(máx)), absolute (VT(1) and VT(2)) ventilatory thresholds, as well as workloads at VT(1) and VT(2) (W(VT1) and W(VT2)) were evaluated during a maximal incremental test on a cycle ergometer. There were significant negative correlations between the individual values of echo intensity with the corresponding individual values of isometric and isokinetic peak torques (60, 180 and 360°(.s-1)) (r=-0.48 to r=-0.64; P<0.05), as well as with W(VT1) (r=-0.46) and W(VT2) (r=-0.50) (P<0.05). In addition, significant positive correlations were observed between torque per unit of muscle mass and cardiovascular parameters (r=0.52 to r=0.60; P<0.001). The present results suggest that the echo intensity analysis using computer-aided gray-scale analysis is a low cost, easily accessible, and a safe method to evaluate the muscle quality, and may contribute to the research of neuromuscular and cardiovascular performances in the elderly.     

Fatigability is increased with age during velocity-dependent contractions of the dorsiflexors

BACKGROUND: Muscle power is more relevant to the activities of daily living than is isometric strength. However, dynamic contractions have received little attention as they relate to the effect of age on muscle fatigue, particularly in very old persons. Thus, the purpose of this study was to investigate fatigue of the dorsiflexors during a velocity-dependent (isotonic) power task in 12 young (26 years), 12 old (64 years), and 12 very old (84 years) men. METHODS: The fatigue protocol involved 25 maximal (as fast as possible) contractions at a load of 20% maximum isometric strength through a 25 degrees range of motion. Electromyographic signals of the tibialis anterior and soleus muscles were recorded to assess agonist activation and antagonist coactivation, respectively. RESULTS: Fatigability increased progressively with age as muscle power decreased by 13% in young men, 19% in old men, and 24% in very old men. In contrast, agonist activation and antagonist coactivation were unaffected by age. During the fatigue protocol, agonist activity decreased by 3%, 5%, and 4%, whereas antagonist activity increased by 11%, 13%, and 13% in young, old, and very old men, respectively. CONCLUSION: These results demonstrate that older adults are more fatigable than young adults during a velocity-dependent power task. This finding is in contrast to the majority of fatigue data previously reported from less functionally relevant isometric or isokinetic tasks.     

Five years of growth hormone replacement therapy in adults: age- and gender-related changes in isometric and isokinetic muscle strength

GH replacement therapy in adults with adult-onset GH deficiency (GHD) has been shown to increase isometric and isokinetic muscle strength in a few trials with limited numbers of patients. In this single center, prospective, open-label study, the effects of 5-yr GH replacement therapy on muscle function were determined in 109 consecutive adults (61 men and 48 women) with adult-onset GHD. The mean initial GH dose was 0.88 mg/d. The dose was gradually lowered, and after 5 yr the mean dose was 0.46 mg/d. The mean IGF-I SD score increased from -1.54 at baseline to 1.53 at study end. A sustained increase in lean body mass and decrease in body fat was observed. The GH treatment induced persistent increases in isometric knee flexor strength, concentric knee flexor strength at an angular velocity of 60 degrees/sec, and right-hand peak grip strength. After correction for age and gender using observed/predicted value ratios, a sustained increase was also observed in isometric (60 degrees) and concentric (180 degrees/sec) knee extensor strength, average right-hand grip strength for 10 sec, and left-hand grip strength. At study end, knee flexor and extensor strength was 96-104% of predicted and hand grip strength was 84-90% of predicted values. The local muscle endurance was transiently decreased after correction for age and gender. No gender difference was found in the treatment responses in muscle strength. However, muscle strength (also after correction for age and gender) was lower in women than men throughout the study period. In conclusion, GH replacement therapy in adults with adult-onset GHD normalized isometric and isokinetic knee flexor and extensor strength. Hand grip strength increased but was not fully normalized.     

Impact of whole-body vibration training versus fitness training on muscle strength and muscle mass in older men: a 1-year randomized controlled trial

BACKGROUND: This randomized controlled study investigated the effects of 1-year whole-body vibration (WBV) training on isometric and explosive muscle strength and muscle mass in community-dwelling men older than 60 years. METHODS: Muscle characteristics of the WBV group (n = 31, 67.3 +/- 0.7 years) were compared with those of a fitness (FIT) group (n = 30, 67.4 +/- 0.8 years) and a control (CON) group (n = 36, 68.6 +/- 0.9 years). Isometric strength of the knee extensors was measured using an isokinetic dynamometer, explosive muscle strength was assessed using a counter movement jump, and muscle mass of the upper leg was determined by computed tomography. RESULTS: Isometric muscle strength, explosive muscle strength, and muscle mass increased significantly in the WBV group (9.8%, 10.9%, and 3.4%, respectively) and in the FIT group (13.1%, 9.8%, and 3.8%, respectively) with the training effects not significantly different between the groups. No significant changes in any parameter were found in the CON group. CONCLUSION: WBV training is as efficient as a fitness program to increase isometric and explosive knee extension strength and muscle mass of the upper leg in community-dwelling older men. These findings suggest that WBV training has potential to prevent or reverse the age-related loss in skeletal muscle mass, referred to as sarcopenia.     

Assessment of lower extremity muscle power in functionally-limited elders

BACKGROUND AND AIMS: The purpose of this study was to assess the reliability and concurrent validity of a new methodology to evaluate lower extremity muscle power in older, functionally limited men and women. METHODS: A cross sectional evaluation was performed on 58 older men (n=27) and women (n=31) (74.2+/-0.9 years). Knee and hip (leg press) and knee extensor power were evaluated on pneumatic and isokinetic resistance equipment. Incremental single attempt power (IP) testing utilized a single attempt at attaining maximum power at each of six external resistances and was compared to multiple attempt pneumatic power (MP) testing determined by the highest of 5 attempts at achieving maximum power at two set resistances and also with power determined by isokinetic dynamometry. RESULTS: Leg press extension MP yielded significantly greater power than IP at both low (mean=225.3+/-11.85 and 183.9+/-11.52 watts respectively, p<0.001) and high (mean=249.7+/-15.25 and 201.7+/-13.18 watts respectively, p<0.001) external resistances. Knee extension MP also produced significantly greater power when compared to IP at low (mean=82.4+/-4.45 and 69.7+/-4.28 watts respectively, p<0.001) and high (mean=93.7+/-6.3 and 83.2+/-5.93 watts respectively, p<0.001) external resistances. MP testing exhibited excellent reliability at both low (leg press extension: Intra Class Correlation (ICC)=0.93, knee extension: ICC=0.87) and high (Leg press extension: ICC=0.85, Knee Extension: ICC=0.91) external resistances. MP knee extension at 70% 1 RM also showed good agreement with average isokinetic power (R2=0.636). CONCLUSIONS: These findings support the reliability and concurrent validity of MP for the evaluation of muscle power in older individuals.     

Isometric and isokinetic muscle strength in patients with fibrositis syndrome. New characteristics for a difficult definable category of patients

A common complaint among patients with fibrositis syndrome is exhaustion and fatique. It was therefore felt desirable to evaluate the muscle strength of these patients compared with normal subjects. Maximum isometric and isokinetic strength of knee extension was measured in 15 patients and 15 healthy matched subjects, using an isokinetic dynamometer (Cybex II). Maximum isometric strength at various knee extension angles (90 degrees, 60 degrees and 30 degrees degrees) was significantly (p less than 0.001) lower in the fibrositis group than in controls, a reduction of approximately 58-66%. Maximum isokinetic strength at various knee extension velocities (30-240 degrees per second) was also significantly (p less than 0.01) lower in the fibrositis group than in controls, the reduction being approximately 41-51%. In conclusion, isometric and isokinetic muscle strength is found to be lower in patients with fibrositis syndrome than in healthy subjects.     

Moderate-intensity resistance exercise training in patients with chronic heart failure improves strength, endurance, heart rate variability, and forearm blood flow

BACKGROUND: Resistance exercise training was applied to patients with chronic heart failure (CHF) on the basis that it may partly reverse deficiencies in skeletal muscle strength and endurance, aerobic power (VO(2peak)), heart rate variability (HRV), and forearm blood flow (FBF) that are all putative factors in the syndrome. METHODS AND RESULTS: Thirty-nine CHF patients (New York Heart Association Functional Class=2.3+/-0.5; left ventricular ejection fraction 28%+/-7%; age 65+/-11 years; 33:6 male:female) underwent 2 identical series of tests, 1 week apart, for strength and endurance of the knee and elbow extensors and flexors, VO(2peak), HRV, FBF at rest, and FBF activated by forearm exercise or limb ischemia. Patients were then randomized to 3 months of resistance training (EX, n=19), consisting of mainly isokinetic (hydraulic) ergometry, interspersed with rest intervals, or continuance with usual care (CON, n=20), after which they underwent repeat endpoint testing. Combining all 4 movement patterns, strength increased for EX by 21+/-30% (mean+/-SD, P<.01) after training, whereas endurance improved 21+/-21% (P<.01). Corresponding data for CON remained almost unchanged (strength P<.005, endurance P<.003 EX versus CON). VO(2peak) improved in EX by 11+/-15% (P<.01), whereas it decreased by 10+/-18% (P<.05) in CON (P<.001 EX versus CON). The ratio of low-frequency to high-frequency spectral power fell after resistance training in EX by 44+/-53% (P<.01), but was unchanged in CON (P<.05 EX versus CON). FBF increased at rest by 20+/-32% (P<.01), and when stimulated by submaximal exercise (24+/-32%, P<.01) or limb ischemia (26+/-45%, P<.01) in EX, but not in CON (P<.01 EX versus CON). CONCLUSIONS: Moderate-intensity resistance exercise training in CHF patients produced favorable changes to skeletal muscle strength and endurance, VO(2peak), FBF, and HRV.     

Quality of life impact of urge incontinence in older persons: a new measure and conceptual structure.

OBJECTIVE: To develop a condition-specific measure for assessing the impact of urge urinary incontinence (UI) on the quality of life (QoL) of older persons. DESIGN: A 32-item Urge Impact Scale (URIS) was drafted using content area data from focus groups composed of urge incontinent older persons. Pilot testing in 21 urge incontinent persons (mean age 67.7 years) resulted in the elimination of eight items by internal consistency, skew, and patient response criteria. The resulting scale (URIS-24) was tested for reliability (internal consistency and test-retest correlation) and construct validity (correlation with UI severity from voiding records) in a separate group of 27 urge incontinent persons (89% women, mean age 72 years). Factor analysis of URIS-24 data from the combined 48 persons was used to explore the conceptual structure underlying urge UI-related QoL. SETTING: University-affiliated community-based practice and tertiary hospital. PARTICIPANTS: Community-dwelling women and men, older than age 60 and with urge incontinence at least twice weekly, recruited from newspaper, newsletter, and radio advertisements. RESULTS: Cronbach's alpha for URIS-32 was 0.84, and for URIS-24 it was 0.94. When administered (mean +/- standard deviation) 9.2 +/- 5.1 days apart, URIS-24 had good test-retest reliability for total scores (interclass coefficient = .88, concordance coefficient = .88), and individual item scores at time 2 were within 1 point (on a 5-category Likert scale) of time 1 answers for 89% of responses. URIS-24 scores had modest but nearly significant correlation with the number of UI episodes (r = -0.39, P = .05). Factor analysis revealed a three component structure corresponding to psychological burden, perception of personal control, and self concept. CONCLUSIONS: The URIS-24 is an internally-consistent, highly reproducible tool for the assessment of the QoL impact of urge UI on older persons. It can be used to evaluate QoL impact by specific items as well as by overall score. Compared with other UI-specific QoL measures, the URIS-24 had similar or superior internal consistency, test-retest reliability, and validity, but it is the first measure designed and tested specifically for older persons with urge UI. These results also highlight the multifactorial structure of urge UI-related QoL and the importance of its psychological dimensions.