Strength training in patients with myotonic dystrophy and hereditary motor and sensory neuropathy: a randomized clinical trial. Effects of training and albuterol on pain and fatigue in facioscapulohumeral muscular dystrophy. Strength training and albuterol in facioscapulohumeral muscular dystrophy. Effect of exercise training on skeletal muscle histology and metabolism in peripheral arterial disease. Physical training in patients with stable chronic heart failure: effects on cardiorespiratory fitness and ultrastructural abnormalities of leg muscles. Low intensity peripheral muscle conditioning improves exercise tolerance and breathlessness in COPD. The effectiveness of aerobic and muscle strength training in patients receiving hemodialysis and EPO: a randomized controlled trial. Randomized trial of progressive resistance training to counteract the myopathy of chronic heart failure. Effect of intra-dialytic, low-intensity strength training on functional capacity in adult haemodialysis patients: a randomized pilot trial.
A randomized clinical trial on the effects of strength training was performed in myotonic dystrophy (MyD) patients and patients with hereditary motor and sensory neuropathy (HMSN). Training and most measurement tools involved the proximal lower extremity muscles. The participants trained 3 times a week for 24 weeks with weights adapted to their force. Strength was evaluated by isokinetically measured knee torque. Fatiguability was assessed by the time an isometric contraction could be sustained. Functional performance was measured by timed motor performance and by questionnaires on functional performance. Serum myoglobin (Mb) levels were determined to detect changes in muscle fiber membrane permeability. The MyD group included 33 participants, and the HMSN group included 29 participants. Within each diagnostic group, patients were individually matched and subsequently randomized for treatment allocation. In the MyD patients, none of the measurement techniques showed any training effect. Neither were there signs of deterioration caused by the training. In the HMSN group, knee torques increased. Timed motor performance did not change, although the questionnaires showed an improvement on items related to upper-leg function. Mb levels did not change significantly as a result of the training. In conclusion, the MyD group showed neither positive nor negative effects of the training protocol, whereas the training produced a moderate increase in strength and leg-related functional performance in the HMSN group. We recently reported a randomised controlled trial on the efficacy of strength training and the beta2-adrenergic agonist albuterol in patients with facioscapulohumeral muscular dystrophy (FSHD). Strength training and albuterol appeared safe interventions with limited positive effect on muscle strength and volume. We concurrently explored the prevalence and the characteristics of pain and fatigue in the participating FSHD patients, because these are probably underreported but clinically relevant symptoms in this disorder. Next, we studied the effects of albuterol and strength training on pain, experienced fatigue, health-related functional status and psychological distress.
                Sixty-five patients were randomised to strength training of elbow flexors and ankle dorsiflexors or non-training. After 26 weeks, albuterol (sustained-release, 8 mg bid) was added in a randomised, double-blind, placebo-controlled design. Outcomes comprised self-reported pain, experienced fatigue, functional status and psychological distress obtained with validated questionnaires at 52 weeks.
                Eighty percent of patients reported chronic persistent or periodic, multifocal pains. Thirty-four percent of the participants were severely fatigued. Strength training and albuterol failed to have a significant effect on all outcomes.
                Pain and fatigue are important features in FSHD. Strength training and albuterol do not have a positive or negative effect on pain, experienced fatigue, functional status and psychological distress. In animals and healthy volunteers beta2-adrenergic agonists increase muscle strength and mass, in particular when combined with strength training. In patients with facioscapulohumeral muscular dystrophy (FSHD) albuterol may exert anabolic effects. The authors evaluated the effect of strength training and albuterol on muscle strength and volume in FSHD.
                Sixty-five patients were randomized to strength training of elbow flexors and ankle dorsiflexors or non-training. After 26 weeks albuterol (sustained-release, 8 mg BID) was added in a randomized, double-blind, placebo-controlled design. Primary outcome was maximum voluntary isometric strength (MVIC) at 52 weeks. Secondary outcomes comprised dynamic strength and muscle volume.
                Training and albuterol were well tolerated. Training of elbow flexors did not result in a significant effect on MVIC, but dynamic strength improved significantly. Elbow flexor MVIC strength increased significantly in albuterol vs placebo treated patients. Ankle dorsiflexor strength decreased in all groups. Eleven out of twelve non-trained muscles in the albuterol group showed a positive effect on MVIC compared to the placebo group (p < 0.05 in seven muscle groups). Muscle volume decreased in the placebo-treated, and increased in the albuterol-treated patients. No synergistic or antagonistic effects were observed between training and albuterol.
                In FSHD strength training and albuterol appear safe interventions with limited positive effect on muscle strength and volume. Consequences of prolonged use are presently unclear, which precludes routine prescription. Patients with symptomatic peripheral arterial occlusive disease have a claudication-limited peak exercise performance that is improved with exercise training. The effects of training on skeletal muscle metabolism were evaluated in 26 patients with claudication, randomized into a 12-wk program of treadmill training (enhances muscle metabolic activity in normal subjects), strength training (stimulates muscle hypertrophy in normal subjects), or a nonexercising control group. Gastrocnemius muscle biopsies were performed at rest and before and after training. After 12 wk, only treadmill training improved peak exercise performance and peak oxygen consumption. Treadmill training did not alter type I or type II fiber area and did not increase citrate synthase activity but was associated with an increase in the percentage of denervated fibers (from 7.6 +/- 5.4 to 15.6 +/- 7.5%, P < 0.05). Improvement in exercise performance with treadmill training was associated with a correlative decrease in the plasma (r = -0.67) and muscle (r = -0.59) short-chain acylcarnitine concentrations (intermediates of oxidative metabolism). Patients in the strength and control groups had no changes in muscle histology or carnitine metabolism, but strength-trained subjects had a decrease in citrate synthase activity. Thus treadmill training increased peak exercise performance, but this benefit was associated with skeletal muscle denervation and the absence of a "classic" mitochondrial training response (increase in citrate synthase activity). The present study confirms the relationship between skeletal muscle acylcarnitine content and function in peripheral arterial occlusive disease, demonstrating that the response to treadmill training was associated with parallel improvements in intermediary metabolism. The present study was designed to evaluate the effect of an ambulatory training program on ultrastructural morphology and the oxidative capacity of skeletal muscle and its relation to central and peripheral hemodynamic variables in patients with chronic heart failure.
                Clinical evidence supports the hypothesis that exercise intolerance in patients with chronic heart failure is not only a consequence of low cardiac output, but is also a result of alterations in oxidative metabolism of skeletal muscle.
                Twenty-two patients were prospectively randomized either to a training group (mean [+/-SD] ejection fraction 26 +/- 9%, n = 12) participating in an ambulatory training program or to a physically inactive control group (ejection fraction 27 +/- 10%, n = 10). At baseline and after 6 months, patients underwent symptom-limited bicycle exercise testing, and central and peripheral hemodynamic variables were measured. Percutaneous needle biopsy samples of the vastus lateralis muscle were obtained at baseline and after 6 months. The ultrastructure of skeletal muscle was analyzed by ultrastructural morphometry.
                After 6 months, patients in the training group achieved an increase in oxygen uptake at the ventilatory threshold of 23% (from 0.86 +/- 0.2 to 1.07 +/- 0.2 liters/min, p < 0.01 vs. control group) and at peak exercise of 31% (from 1.49 +/- 0.4 to 1.95 +/- 0.4 liters/min, p < 0.01 vs. control group). There was no significant change in oxygen uptake at the ventilatory threshold and at peak exercise in the control group. The total volume density of mitochondria and volume density of cytochrome c oxidase-positive mitochondria increased significantly by 19% (from 4.7 +/- 1.5 to 5.6 +/- 1.5 vol%, p < 0.05 vs. control group) and by 41% (from 2.2 +/- 1.0 to 3.1 +/- 1.0 vol%, p < 0.05 vs. control group) after 6 months of regular physical exercise. Cardiac output at rest and at submaximal exercise remained unchanged but increased during maximal symptom-limited exercise from 11.9 +/- 4.0 to 14.1 +/- 3.3 liters/min in the training group (p < 0.05 vs. baseline; p = NS vs. control group). Peak leg oxygen consumption increased significantly by 45% (from 510 +/- 172 to 740 +/- 254 ml/min, p < 0.01 vs. control group). Changes in cytochrome c oxidase-positive mitochondria were significantly related to changes in oxygen uptake at the ventilatory threshold (r = 0.82, p < 0.0001) and at peak exercise (r = 0.87, p < 0.0001).
                Regular physical training increases maximal exercise tolerance and delays anaerobic metabolism during submaximal exercise in patients with stable chronic heart failure. Improved functional capacity is closely linked to an exercise-induced increase in the oxidative capacity of skeletal muscle. This randomized, controlled study investigated the physiological effects of a specially designed 12 week programme of isolated conditioning of peripheral skeletal muscle groups. The programme required minimal infrastructure in order to allow continued rehabilitation at home after familiarization within hospital. Forty eight patients, aged 40-72 yrs with chronic obstructive pulmonary disease (COPD) (mean (SD) forced expiratory volume in one second (FEV1) 61 (27)% of predicted normal) were randomly allocated into training (n = 32) and control (n = 16) groups. Physiological assessments were performed before and after the 12 week study period, and included peripheral muscle endurance and strength, whole body endurance, maximal exercise capacity (maximum oxygen consumption (V'O2,max)) and lung function. The training group showed significant improvement in a variety of measures of upper and lower peripheral muscle performance, with no additional breathlessness. Whole body endurance measured by free arm treadmill walking increased by 6,372 (3,932-8,812) 3 (p < 0.001). Symptom-limited maximal V'O2 was unchanged. However, the training group showed a reduction in ventilatory equivalents for oxygen and carbon dioxide, both at peak exercise and at equivalent work rate (Wmax). In summary, low intensity isolated peripheral muscle conditioning is well-tolerated, simple and easy to perform at home. The various physiological benefits should enable patients across the range of severity of chronic obstructive pulmonary disease to improve daily functioning. Individuals with end-stage renal disease on hemodialysis therapy have reduced aerobic exercise capacity and reduced muscle strength.
                This was a single-blind, randomized, placebo-controlled trial of an exercise intervention in hemodialysis patients administered erythropoietin. The intervention consisted of progressive resisted isotonic quadriceps and hamstrings exercise and training on a cycle ergometer three times weekly for 12 weeks. Individuals in the control group underwent a nonprogressive program of range-of-motion exercises. Both groups were observed for an additional 5 months without intervention. Outcomes were assessed without knowledge of treatment assignment at baseline, 12 weeks, and 5 months. A healthy age- and sex-matched sample provided comparative data.
                Our sample was relatively high functioning, with a mean score on the Physical Function subscale of the Short Form 36 (SF-36) of 76 of 100. At 12 weeks, there were large and statistically significant differences in favor of the experimental group on the submaximal exercise test (14 W; 95% confidence interval, 2 to 26) and muscle strength (45 lb; 95% confidence interval, 9 to 81), but not in the 6-minute walk, symptoms questionnaire, or SF-36. Differences between the intervention and control groups at 12 weeks were not evident on retesting 5 months after the end of the intervention. Compared with the healthy sample, patients were significantly lower functioning on the submaximal exercise test, muscle strength, and 6-minute walk test at baseline.
                In this high-functioning sample, the exercise program improved physical impairment measures, but had no effect on symptoms or health-related quality of life. The impact on patients with a greater degree of physical dysfunction needs to be rigorously studied.
                Copyright 2002 by the National Kidney Foundation, Inc. Chronic heart failure (CHF) is characterized by a skeletal muscle myopathy not optimally addressed by current treatment paradigms or aerobic exercise. Sixteen older women with CHF were compared with 80 age-matched peers without CHF and randomized to progressive resistance training or control stretching exercises for 10 wk. Women with CHF had significantly lower muscle strength (P < 0.0001) but comparable aerobic capacity to women without CHF. Exercise training was well tolerated and resulted in no changes in resting cardiac indexes in CHF patients. Strength improved by an average of 43.4 +/- 8.8% in resistance trainers vs. -1.7 +/- 2.8% in controls (P = 0.001), muscle endurance by 299 +/- 66% vs. 1 +/- 3% (P = 0.001), and 6-min walk distance by 49 +/- 14 m (13%) vs. -3 +/- 19 m (-3%) (P = 0.03). Increases in type I fiber area (9.5 +/- 16%) and citrate synthase activity (35 +/- 21%) in skeletal muscle were independently predictive of improved 6-min walk distance (r2 = 0.78; P = 0.0024). High-intensity progressive resistance training improves impaired skeletal muscle characteristics and overall exercise performance in older women with CHF. These gains are largely explained by skeletal muscle and not resting cardiac adaptations. Kidney failure is associated with muscle wasting and physical impairment. Moderate- to high-intensity strength training improves physical performance, nutritional status and quality of life in people with chronic kidney disease and in dialysis patients. However, the effect of low-intensity strength training has not been well documented, thus representing the objective of this pilot study.
                Fifty participants (mean +/- SD, age 69 +/- 13 years) receiving long-term haemodialysis (3.7 +/- 4.2 years) were randomized to intra-dialytic low-intensity strength training or stretching (attention-control) exercises twice weekly for a total of 48 exercise sessions. The primary study outcome was physical performance assessed by the Short Physical Performance Battery score (SPPB) after 36 sessions, if available, or carried forward from 24 sessions. Secondary outcomes included lower body strength, body composition and quality of life. Measurements were obtained at baseline and at completion of 24 (mid), 36 (post) and 48 (final) exercise sessions.
                Baseline median (IQR) SPPB score was 6.0 (5.0), with 57% of the participants having SPPB scores below 7. Exercise adherence was 89 +/- 15%. The primary outcome could be computed in 44 participants. SPPB improved in the strength training group compared to the attention-control group [21.1% (43.1%) vs. 0.2% (38.4%), respectively, P = 0.03]. Similarly, strength training participants exhibited significant improvements from baseline compared to the control group in knee extensor strength, leisure-time physical activity and self-reported physical function and activities of daily living (ADL) disability; all P < 0.02. Adverse events were common but not related to study participation.
                Intra-dialytic, low-intensity progressive strength training was safe and effective among maintenance dialysis patients. Further studies are needed to establish the generalizability of this strength training program in dialysis patients.
In myotonic dystrophy and facioscapulohumeral muscular dystrophy, moderate-intensity strength training appears not to do harm but there is insufficient evidence to conclude that it offers benefit. In mitochondrial myopathy, aerobic exercise combined with strength training appears to be safe and may be effective in increasing submaximal endurance capacity. Limitations in the design of studies in other muscle diseases prevent more general conclusions in these disorders.