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PubMed1995

Long-term resistance training in the elderly: effects on dynamic strength, exercise capacity, muscle, and bone.

We examined the effects of 42 weeks of progressive weight-lifting training on dynamic muscle strength, peak power output in cycle ergometry, symptom limited endurance during progressive treadmill walking and stair climbing, knee extensor cross-sectional areas, and bone mineral density and content in healthy males and females aged 60-80 years, currently enrolled in a 2-year resistance training program. Subjects were randomized into either exercise (EX) or control (CON) groups (60-70 years: 38 males and 36 females; 70-80 years: 25 males and 43 females). EX trained several muscle groups twice per week for 42 weeks at intensities ranging from 50-80% of the load that they could lift once only (1 RM); CON did usual daily activities. After the 10 months there was no change in 1 RM strength in CON, but significant gains (mean increases up to 65%) in EX (no independent age or gender effects); 30% and 47% of the increase in 1 RM had occurred by 6 and 12 weeks, respectively. In EX, the 7.1% increase in peak cycling power output was significantly greater than in CON (+1.1%). The 17.8% improvement in symptom limited treadmill walking endurance was also greater than in CON (+3.4%), but the difference between groups during stair climbing was not significant (EX + 57%, CON + 33%). The cross-sectional areas of the knee extensors increased significantly by 5.5% in EX but were unchanged in CON. There were no changes in bone mineral density or content in either group. We conclude that long-term resistance training in older people is feasible and results in increases in dynamic muscle strength, muscle size, and functional capacity.

Aged↗

PubMed1986

Structural changes in skeletal muscle tissue with heavy-resistance exercise.

Muscle strength, muscle cross-sectional area, fiber size, fiber type distribution, capillarity, and mitochondrial volume were estimated before and after 6 weeks of heavy-resistance exercise. Isokinetic torque production of the knee extensor muscles increased by a total of 17.6%, mainly during the first half of the training period. The cross-sectional area of the vastus lateralis muscle increased by 8.4%, mainly during the second half of the training period. Morphometrically determined fiber size, fiber type distribution, and capillarity from biopsies of vastus lateralis did not change significantly with training. Likewise, the surface densities of inner and outer mitochondrial membranes as well as the volume density of myofibrils remained unchanged. In contrast, the volume density of mitochondria decreased by 9.6%. However, due to the increase in total muscle volume, the calculated absolute volume of mitochondria remained constant, whereas the absolute volume of myofibrils increased by 10%. It is concluded that strength training of short duration in previously untrained young male subjects does not change the ultrastructural composition of mitochondria and that the apparent dilution of mitochondria can quantitatively be accounted for by the increase in myofibrillar volume.

Adenosine Triphosphatases↗

PubMed2006

Strength, but not muscle mass, is associated with mortality in the health, aging and body composition study cohort.

BACKGROUND: Although muscle strength and mass are highly correlated, the relationship between direct measures of low muscle mass (sarcopenia) and strength in association with mortality has not been examined. METHODS: Total mortality rates were examined in the Health, Aging and Body Composition (Health ABC) Study in 2292 participants (aged 70-79 years, 51.6% women, and 38.8% black). Knee extension strength was measured with isokinetic dynamometry, grip strength with isometric dynamometry. Thigh muscle area was measured by computed tomography (CT) scan, and leg and arm lean soft tissue mass were determined by dual energy x-ray absorptiometry (DXA). Both strength and muscle size were assessed as in gender-specific Cox proportional hazards models, with age, race, comorbidities, smoking status, level of physical activity, fat area by CT or fat mass by DXA, height, and markers of inflammation, including interleukin-6, C-reactive protein, and tumor necrosis factor-alpha considered as potential confounders. RESULTS: There were 286 deaths over an average of 4.9 (standard deviation = 0.9) years of follow-up. Both quadriceps and grip strength were strongly related to mortality. For quadriceps strength (per standard deviation of 38 Nm), the crude hazard ratio for men was 1.51 (95% confidence interval, 1.28-1.79) and 1.65 (95% confidence interval, 1.19-2.30) for women. Muscle size, determined by either CT area or DXA regional lean mass, was not strongly related to mortality. In the models of quadriceps strength and mortality, adjustment for muscle area or regional lean mass only slightly attenuated the associations. Further adjustment for other factors also had minimal effect on the association of quadriceps strength with mortality. Associations of grip strength with mortality were similar. CONCLUSION: Low muscle mass did not explain the strong association of strength with mortality, demonstrating that muscle strength as a marker of muscle quality is more important than quantity in estimating mortality risk. Grip strength provided risk estimates similar to those of quadriceps strength.

Age Factors↗

PubMed1988

Effects of chronic smoking on respiratory muscle function.

To investigate the effects of chronic smoking on respiratory muscle function, 20 heavy smokers and 20 nonsmokers were studied. After familiarization, respiratory muscle strength, inspiratory muscle endurance and the spirometric function (including FVC, FEV 1, FEV1/FVC, tidal volume, breathing rate and duty cycle) were measured. The respiratory muscle strength was indicated by the maximal static inspiratory and expiratory pressures (PIMmax and PEMmax). Inspiratory muscle endurance was determined by a modified Nickerson-Keens method. The results showed that long-term smoking drastically enhanced expiratory muscle strength (p less than 0.01) and slightly increased inspiratory muscle strength (p less than 0.05). The inspiratory muscle endurance, in contrast, was reduced in the smokers (p less than 0.05). We also observed the tendency of decreases in the duty cycle and FEV1/FVC in the smokers. We, therefore, conclude that chronic smoking can raise respiratory muscle strength but impair the inspiratory muscle endurance.

Adult↗

PubMed2000

Body composition predicts bone mineral density and balance in premenopausal women.

Low bone mineral density (BMD) and poor stability both contribute to increased risk of fractures associated with a fall. Our aim in this cross-sectional study was to determine the anthropometric and/or performance variables that best predicted BMD and stability in women. BMD, body composition, muscle strength, muscle power, and dynamic stability were evaluated in 61 women (age 40 +/- 4 years; % body fat 27% +/- 5%). In correlation analyses, BMD at all sites was significantly related to height, lean mass, strength, and leg power (r2 = 0.25-0.49). Significant inverse relationships were found between all independent variables and dynamic stability (r2 = 0.23-0.52). In stepwise regression, lean mass independently predicted BMD at the femoral neck (R2 = 0.20), total hip (R2 = 0.24), and whole body (R2 = 0.17), whereas hip abductor torque predicted 23% of the variance in trochanter BMD and added 6% to the variance in total hip BMD. Leg power was the only predictor of spine BMD (R2 = 0.14). Fat and lean mass both independently predicted poor performance on postural stability, with fat mass contributing 31% of the total variance (R2 = 0.38). In conclusion, we found lean mass to be a robust predictor of BMD in premenopausal women. Furthermore, both hip abductor torque and leg power independently predicted BMD at clinically relevant fracture sites (hip and spine). The finding that higher fat mass contributes to the majority of the variance in poor stability indicates that greater fat mass may compromise stability and, thus, increase fall risk in heavier individuals.

Absorptiometry, Photon↗

PubMed1994

Changes in muscle morphology, strength and enzymes in a 4-5-year follow-up of subjects with poliomyelitis sequelae.

Twenty subjects with polio sequelae were studied on two occasions 4-5 years apart by means of dynamometer measurements of knee-extension and flexion strength and muscle biopsy for histochemical and enzymatic analyses. The subjects were divided into those who reported (unstable, n = 12) and did not report (stable, n = 8) new or increased muscle weakness in the tested leg between the two examinations. Muscle strength decreased significantly in the unstable subjects, but only for knee-flexion in the stable subjects. However, the endurance test comprising 50 consecutive knee-extensions at 180 degrees/sec showed increased fatigability at the second examination only in the stable subjects. Most subjects had markedly increased muscle fiber areas, which in some subjects increased further, but in those already with very extreme hypertrophy the fiber size decreased. Capillarization and activity of citrate-synthase were decreased at the initial examination, but no significant further reduction was observed at the second examination. The results demonstrate individual patterns in the compensatory process for the presumed loss of motor units.

Adult↗

PubMed2000

Efficacy of early treatment of severe juvenile dermatomyositis with intravenous methylprednisolone and methotrexate.

A pilot study was conducted to assess the efficacy of early treatment of severe juvenile dermatomyositis (JDMS) patients with intravenous methylprednisolone (IVMP) and methotrexate (MTX). Twelve children diagnosed with severe JDMS were treated with IVMP and MTX. Six patients were treated early (within 6 weeks of the diagnosis) while in the other six patients, MTX was started 5-72 months after the diagnosis was made. The clinical responses of the patients to treatment, including alterations in muscle strength, muscle enzyme levels and corticosteroid dosage as well as the development of side-effects, were recorded. The indications for starting the treatment were defined and documented. The primary measures of response were resolution of the clinical indications for treatment, decreased activity of the disease manifestations and tapering of the corticosteroids to the minimal dose or discontinuation without clinical or biochemical flare. The main indications for starting IVMP and MTX were dysphagia and severe cutaneous vasculitis. All the patients received MTX orally for at least 8 months, as well as IVMP (30 mg/kg/dose), but none of the patients was on additional second-line treatments. The six patients who were treated early with MTX showed a significant clinical improvement. In five out of the six, the corticosteroid dosage was eventually reduced to <5 mg/day. None of them developed calcinosis. In contrast, two of the six patients who were treated late with MTX developed calcinosis. This study suggests that MTX and IVMP are a useful combination in the early treatment of severe JDMS. Given the fact that our sample was small, further studies in a controlled trial are necessary to confirm these findings.

Administration, Oral↗

PubMed2003

Exercise capacity and muscle structure in kidney recipient and twin donor.

Exercise capacity and muscle function are known to be abnormal in patients with renal disease. We present a case study in which we studied a kidney transplant recipient who received a kidney from his identical twin. Testing included maximal exercise testing with measurement of oxygen uptake (VO2max), isokinetic muscle function testing, body composition analysis using dual energy X-ray absorptiometry (DEXA) imaging and quality of life using The Medical Outcomes Short Form (SF-36) questionnaire. Muscle biopsies were also analysed for fibre composition and size and ultrastructure. We found that the twin recipient had lower values for VO2max, muscle strength, muscle mass and quality of life scales (physical domains) compared with the twin donor. Muscle fibre composition was identical in the twins, however, muscle fibres size was reduced in the twin donor in Type I, and Type IIA fibre types. The twin recipient also showed lower fibre density (volume percentage) and greater intrafibrillar space than the donor. The twins were both sedentary, thus we conclude that the low exercise capacity and abnormalities observed in the recipient are characteristics of renal failure, and not the result of physical deconditioning, nor was it related to prednisone therapy, which may negatively affect muscle function.

Absorptiometry, Photon↗

PubMed1999

Low back strengthening for the prevention and treatment of low back pain.

PURPOSE: Chronic low back pain (CLBP) remains one of the most difficult and costly medical problems in the industrialized world. A review of nineteenth and early twentieth century spine rehabilitation shows that back disorders were commonly treated with aggressive and specific progressive resistance exercise (PRE). Despite a lack of scientific evidence to support their efficacy, therapeutic approaches to back rehabilitation over the past 30 yr have focused primarily upon passive care for symptom relief. Recent spine rehabilitation programs have returned to active reconditioning PRE centered around low back strengthening to restore normal musculoskeletal function. Research has shown that lumbar extension exercise using PRE significantly increases strength and decreases pain in CLBP patients. It appears that isolated lumbar extension exercise with the pelvis stabilized using specialized equipment elicits the most favorable improvements in low back strength, muscle cross-sectional area, and vertebral bone mineral density (BMD). These improvements occur with a low training volume of 1 set of 8 to 15 repetitions performed to volitional fatigue one time per week. CLBP patients participating in isolated lumbar extension PRE programs demonstrate significant reductions in pain and symptoms associated with improved muscle strength, endurance, and joint mobility. Improvements occur independent of diagnosis, are long-lasting, and appear to result in less re-utilization of the health care system than other more passive treatments. Low back strengthening shows promise for the reduction of industrial back injuries and associated costs.

Back Injuries↗

PubMed2001

Effects of resistance training on the rate of muscle protein synthesis in frail elderly people.

Advancing age is associated with a reduction in skeletal muscle protein, muscle strength, muscle quality, and chemical modifications that may impair protein function. Sarcopenia has been coupled with physical disability, frailty, and a loss of independent function. Using stable isotope tracer methodologies and mass spectrometric detection, we observed: (a) 76-92-year-old physically frail and 62-74-year-old middle-age adults have lower mixed muscle protein synthetic rates than 20-32-year-old men and women; (b) 2 weeks and 3 months of weightlifting exercise increased the synthetic rate of myosin heavy chain (MHC) and mixed muscle proteins to a similar magnitude in frail, middle-age, and young women and men; (c) Serum myostatin-immunoreactive protein levels were elevated in physically frail women and were inversely correlated with lean mass. This suggests that the protein synthetic machinery adapts rapidly to increased contractile activity and that the adaptive response(s) are maintained even in frail elders.

Adaptation, Physiological↗

PubMed2003

[Exercise and physical activities for the prevention of osteoporotic fractures: a review of the evidence].

According that osteoporosis is the common condition in an aging society such as in Japan, much progress has been made in understanding the treatment and prevention of osteoporosis. Among potential risk factors, exercise and physical activities have been recognized as lifestyle factors that might influence the risk of osteoporosis and osteoporotic fractures. To assess the relationship between exercises including physical activities and the risk for low bone mass and osteoporosis-related fractures, a literature search over past 13 years was conducted. Accumulating evidence indicates that exercises decrease the risk for hip fractures among middle aged and older men and women. Exercises also help to maintain muscle strength, muscle volume, balance, and joint flexibility, which might prevent falls and fall-related fractures. One randomized controlled trial showed back-stretching exercise reduced the risk for vertebral fractures. The literature search also indicates that high-impact and/or weight-bearing exercise might increase the bone density in the elderly and the peak bone mass among young women, while there is no association between moderate or lower-impact exercise and bone mineral density. Future research should be required to evaluate the types and quantity of physical activity needed for the prevention of osteoporosis.

Aged↗

PubMed2005

[Effects of a exercise program on body composition, physical fitness and lipid metabolism for middle-aged obese women].

PURPOSE: This study was to examine the effects of an exercise program for middle-aged obese women. METHOD: The exercise program combined folk dance and resistance training. The subjects group consisted of 85 middle-aged obese women between 40 and 60 years of age. Three 8 week sessions consisted of a 55-80% maximum heart rate (MHR) exercise for 60-90 minutes a day and 3 times a week from March to November, 2004. Data was collected through a pre- and post-exercise test before and after each session. Data was collected with Inbody, dynamometer and blood. This data was analyzed by descriptive statistics, and a paired t-test with an SPSS/PC (10.0 version) program. RESULTS: There were significant positive changes in body weight, body fat mass, body mass index, percent body fat, muscle strength, muscle endurance, flexibility, and balance quality, but no significant positive changes in skeletal mass, fat free mass, percent abdominal fat (waist-hip ratio), visceral fat area, agility, total cholesterol, high density lipoprotein cholesterol, or triglycerides. CONCLUSION: This study showed that an exercise program has partially positive effects for middle-aged obese women. The results of this study show that exercise at community health centers should continue for middle-aged obese women's health.

Adult↗

PubMedDate not supplied

Functional outcome of myositis patients: can a low-dose glucocorticoid regimen achieve good functional results?

OBJECTIVE: During the last few years, in an attempt to reduce the side effects of glucocorticoid (GC) therapy, we have been treating polymyositis-dermatomyositis (PM-DM) patients with a lower starting dose of GC than is classically recommended. In order to validate this approach, we performed a functional re-evaluation of these PM-DM patients. METHODS: A comprehensive protocol evaluating muscle strength, muscle function, CK levels, persistence of spontaneous activity on electromyography, disability in daily life activities and degree of dependence was applied in 25 non-cancer-associated biopsy-proven PM-DM patients, 15 of whom had been treated with a high-dose regimen (i.e. > 0.5 mg prednisolone/kg/day) and 10 with a low-dose regimen (i.e. < or = 0.5 mg prednisolone/kg/day). RESULTS: Our results indicate that the functional outcome of PM-DM patients given a low-dose starting regimen of GC does not differ from that observed in patients given higher doses. Interestingly, vertebral fractures were less common in patients treated with lower GC doses. CONCLUSIONS: Although our analysis has certain shortcomings, including the small number of patients investigated and their uncontrolled assignment to a low-dose or a high-dose GC regimen, the results of this retrospective study suggest that a low-dose starting regimen of GC can achieve a good functional outcome in PM-DM patients, with a reduction of treatment-related disability. This approach would be welcome as a step forward should it be validated by a longitudinal study.

Activities of Daily Living↗

PubMedDate not supplied

[Clinical techniques for use in neurological physical examinations. II. Motor and reflex functions].

AIMS: The aim of this study is to highlight the chief practical aspects of the techniques used in the neurological physical examination of the motor and reflex functions. DEVELOPMENT: We recommend clinicians to carry out a brief but consistent and effective exploration in a systematic, flexible and orderly manner to check for abnormalities in the motor and reflex functions of the nervous system. Should any anomalies be detected, then a more detailed and thorough neurological exploration must be performed selectively. We present a detailed review of the practical aspects of the main techniques used in the physical examination of these neurological categories. The motor function is explored using techniques that examine muscle tone, muscle strength, muscle fatigability, hypokinesia, tremor, coordination and gait. Lastly, in this category several manoeuvres that are useful in hysterical or mimicking paralyses are also dealt with. Reflexes to examination are usually divided into: 1. Myotatic reflexes; 2. Cutaneomucous reflexes; 3. Spinal cord or defence automatism reflexes; 4. Posture and attitude reflexes. We also add the study of primitive pathological reflexes, remote reflexes, synkinesias and signs of meningeal irritation. CONCLUSIONS: We present a detailed description of the main clinical techniques used in the neurological physical examination of motility and reflexes, as well as an approach that allows them to be performed on adult patients. In addition, we underline the importance of physically examining the nervous system in contemporary medicine and the need to continually perfect the way these techniques are performed in order to achieve an efficient clinical practice.

Humans↗

PubMed2005

[Intervention in lifestyle factors for the prevention of osteoporosis and osteoporotic fractures].

According that osteoporosis is the common condition in an aging society such as in Japan, much progress has been made in understanding the treatment and prevention of osteoporosis. Among potential risk factors, exercise, smoking, and alcohol consumption have been recognised as important lifestyle factors that might influence the risk of osteoporosis and osteoporotic fractures. To assess the relationship between these lifestyle factors and the risk for low bone mass and osteoporosis-related fractures, a systematic literature search over past 13 years was conducted. Accumulating evidence indicates that exercises decrease the risk for hip fractures among middle aged and older men and women. Exercises also help to maintain muscle strength, muscle volume, balance, and joint flexibility, which might prevent falls and fall-related fractures. One randomised controlled trial indicates that high-impact and/or weight-bearing exercise might increase the bone density in the elderly and the peak bone mass among young women. The literature search also address that there is an association between cigarette smoking and the risk of osteoporosis. Smoking cessation is effective to decrease the risk for both osteoporosis and osteoporotic fractures. Future research should be required to evaluate the alcohol consumption and osteoporosis.

Adult↗

PubMed2005

Acute effects of cold and muscle vibration on maximal grip strength and muscle endurance in normal subjects.

The objective of this study was to compare the acute effects of 10 minutes cold application and 50Hz, 90 seconds vibration of forearm muscles on maximum grip strength and muscle endurance in apparently healthy young adults. This within-subject factorial research study recruited eighty-nine subjects (49 males and 40 males) using a sample of convenience. Baseline maximum grip strength and endurance index were measured using a Jamar dynamometer. Cold and muscle vibration were applied within 48 hours interval to the forearm muscles of the subjects. Their grip strength and endurance index were measured; immediately, 5, and 10 minutes post-application of either stimuli. Data were analysed using independent t-test and one-way analysis of variance at 0.05 alpha. Results showed that neither vibration (P>0.05) nor cold (P>0.05) produced any significant effect on the maximum grip strength and the grip endurance at 5 and 10 minutes post application. The subjects however recorded significantly higher endurance index immediately post cold than they did immediately post vibration (P<0.05). We concluded that grip endurance was enhanced more by cold application than by muscle vibration. Cold rather than vibration may therefore be used to facilitate grip endurance during hand rehabilitation.

Acute Disease↗

PubMed2006

Resistance training and reduction of treatment side effects in prostate cancer patients.

PURPOSE: To examine the effect of progressive resistance training on muscle function, functional performance, balance, body composition, and muscle thickness in men receiving androgen deprivation for prostate cancer. METHODS: Ten men aged 59-82 yr on androgen deprivation for localized prostate cancer undertook progressive resistance training for 20 wk at 6- to 12-repetition maximum (RM) for 12 upper- and lower-body exercises in a university exercise rehabilitation clinic. Outcome measures included muscle strength and muscle endurance for the upper and lower body, functional performance (repeated chair rise, usual and fast 6-m walk, 6-m backwards walk, stair climb, and 400-m walk time), and balance by sensory organization test. Body composition was measured by dual-energy x-ray absorptiometry and muscle thickness at four anatomical sites by B-mode ultrasound. Blood samples were assessed for prostate specific antigen (PSA), testosterone, growth hormone (GH), cortisol, and hemoglobin. RESULTS: Muscle strength (chest press, 40.5%; seated row, 41.9%; leg press, 96.3%; P < 0.001) and muscle endurance (chest press, 114.9%; leg press, 167.1%; P < 0.001) increased significantly after training. Significant improvement (P < 0.05) occurred in the 6-m usual walk (14.1%), 6-m backwards walk (22.3%), chair rise (26.8%), stair climbing (10.4%), 400-m walk (7.4%), and balance (7.8%). Muscle thickness increased (P < 0.05) by 15.7% at the quadriceps site. Whole-body lean mass was preserved with no change in fat mass. There were no significant changes in PSA, testosterone, GH, cortisol, or hemoglobin. CONCLUSIONS: Progressive resistance exercise has beneficial effects on muscle strength, functional performance and balance in older men receiving androgen deprivation for prostate cancer and should be considered to preserve body composition and reduce treatment side effects.

Aged↗

PubMed1996

Stump length as related to atrophy and strength of the thigh muscles in trans-tibial amputees.

Stump length and the thigh muscles strength of the amputated limb are among the major factors influencing outcome of prosthetic rehabilitation of trans-tibial amputees. In the present study the authors evaluated and compared the strength of quadriceps and hamstrings muscles of both limbs in trans-tibial amputees, as measured by means of an electrical dynamometer. The obtained results showed that the thigh muscles of the sound limbs are significantly stronger than those of the amputated limbs (p < 0.01). The results obtained for amputees with shorter stumps were compared with those with longer stumps. In the group of amputees (n = 9) with a stump shorter than 15.1 cm, values of peak torque (in isokinetic contraction) and maximal average torque (in isometric contraction) were significantly (p < 0.5) weaker when compared to those (n = 9) with a stump longer than 15.1 cm. The results obtained for amputees with a higher rate of thigh muscle atrophy were compared to those with lesser atrophy. In the group of amputees where muscle atrophy was accompanied by decrease in thigh girth of over 5.9 cm, muscles strength did not significantly decrease (p < 0.5) as compared to amputees where thigh girth decrease was less than 5.9 cm. It is concluded that atrophy of the thigh muscles of trans-tibial amputees is accompanied with a significant decrease in strength. In amputees with a short stump, the short lever action provided by the stump interferes with the ability of the thigh muscles to control the prosthesis efficiently during daily activities such as standing and walking.

Activities of Daily Living↗