Strength training and aerobic exercise training for muscle disease

BACKGROUND

Strength training or aerobic exercise programmes, or both, might optimise muscle and cardiorespiratory function and prevent additional disuse atrophy and deconditioning in people with a muscle disease. This is an update of a review first published in 2004 and last updated in 2013. We undertook an update to incorporate new evidence in this active area of research.

OBJECTIVES

To assess the effects (benefits and harms) of strength training and aerobic exercise training in people with a muscle disease.

SEARCH METHODS

We searched Cochrane Neuromuscular's Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL in November 2018 and clinical trials registries in December 2018.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs or cross-over RCTs comparing strength or aerobic exercise training, or both lasting at least six weeks, to no training in people with a well-described muscle disease diagnosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 14 trials of aerobic exercise, strength training, or both, with an exercise duration of eight to 52 weeks, which included 428 participants with facioscapulohumeral muscular dystrophy (FSHD), dermatomyositis, polymyositis, mitochondrial myopathy, Duchenne muscular dystrophy (DMD), or myotonic dystrophy. Risk of bias was variable, as blinding of participants was not possible, some trials did not blind outcome assessors, and some did not use an intention-to-treat analysis. Strength training compared to no training (3 trials) For participants with FSHD (35 participants), there was low-certainty evidence of little or no effect on dynamic strength of elbow flexors (MD 1.2 kgF, 95% CI -0.2 to 2.6), on isometric strength of elbow flexors (MD 0.5 kgF, 95% CI -0.7 to 1.8), and ankle dorsiflexors (MD 0.4 kgF, 95% CI -2.4 to 3.2), and on dynamic strength of ankle dorsiflexors (MD -0.4 kgF, 95% CI -2.3 to 1.4). For participants with myotonic dystrophy type 1 (35 participants), there was very low-certainty evidence of a slight improvement in isometric wrist extensor strength (MD 8.0 N, 95% CI 0.7 to 15.3) and of little or no effect on hand grip force (MD 6.0 N, 95% CI -6.7 to 18.7), pinch grip force (MD 1.0 N, 95% CI -3.3 to 5.3) and isometric wrist flexor force (MD 7.0 N, 95% CI -3.4 to 17.4). Aerobic exercise training compared to no training (5 trials) For participants with DMD there was very low-certainty evidence regarding the number of leg revolutions (MD 14.0, 95% CI -89.0 to 117.0; 23 participants) or arm revolutions (MD 34.8, 95% CI -68.2 to 137.8; 23 participants), during an assisted six-minute cycle test, and very low-certainty evidence regarding muscle strength (MD 1.7, 95% CI -1.9 to 5.3; 15 participants). For participants with FSHD, there was low-certainty evidence of improvement in aerobic capacity (MD 1.1 L/min, 95% CI 0.4 to 1.8, 38 participants) and of little or no effect on knee extension strength (MD 0.1 kg, 95% CI -0.7 to 0.9, 52 participants). For participants with dermatomyositis and polymyositis (14 participants), there was very low-certainty evidence regarding aerobic capacity (MD 14.6, 95% CI -1.0 to 30.2). Combined aerobic exercise and strength training compared to no training (6 trials) For participants with juvenile dermatomyositis (26 participants) there was low-certainty evidence of an improvement in knee extensor strength on the right (MD 36.0 N, 95% CI 25.0 to 47.1) and left (MD 17 N 95% CI 0.5 to 33.5), but low-certainty evidence of little or no effect on maximum force of hip flexors on the right (MD -9.0 N, 95% CI -22.4 to 4.4) or left (MD 6.0 N, 95% CI -6.6 to 18.6). This trial also provided low-certainty evidence of a slight decrease of aerobic capacity (MD -1.2 min, 95% CI -1.6 to 0.9). For participants with dermatomyositis and polymyositis (21 participants), we found very low-certainty evidence for slight increases in muscle strength as measured by dynamic strength of knee extensors on the right (MD 2.5 kg, 95% CI 1.8 to 3.3) and on the left (MD 2.7 kg, 95% CI 2.0 to 3.4) and no clear effect in isometric muscle strength of eight different muscles (MD 1.0, 95% CI -1.1 to 3.1). There was very low-certainty evidence that there may be an increase in aerobic capacity, as measured with time to exhaustion in an incremental cycle test (17.5 min, 95% CI 8.0 to 27.0) and power performed at VO₂ max (maximal oxygen uptake) (18 W, 95% CI 15.0 to 21.0). For participants with mitochondrial myopathy (18 participants), we found very low-certainty evidence regarding shoulder muscle (MD -5.0 kg, 95% CI -14.7 to 4.7), pectoralis major muscle (MD 6.4 kg, 95% CI -2.9 to 15.7), and anterior arm muscle strength (MD 7.3 kg, 95% CI -2.9 to 17.5). We found very low-certainty evidence regarding aerobic capacity, as measured with mean time cycled (MD 23.7 min, 95% CI 2.6 to 44.8) and mean distance cycled until exhaustion (MD 9.7 km, 95% CI 1.5 to 17.9). One trial in myotonic dystrophy type 1 (35 participants) did not provide data on muscle strength or aerobic capacity following combined training. In this trial, muscle strength deteriorated in one person and one person had worse daytime sleepiness (very low-certainty evidence). For participants with FSHD (16 participants), we found very low-certainty evidence regarding muscle strength, aerobic capacity and VO₂ peak; the results were very imprecise. Most trials reported no adverse events other than muscle soreness or joint complaints (low- to very low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence regarding strength training and aerobic exercise interventions remains uncertain. Evidence suggests that strength training alone may have little or no effect, and that aerobic exercise training alone may lead to a possible improvement in aerobic capacity, but only for participants with FSHD. For combined aerobic exercise and strength training, there may be slight increases in muscle strength and aerobic capacity for people with dermatomyositis and polymyositis, and a slight decrease in aerobic capacity and increase in muscle strength for people with juvenile dermatomyositis. More research with robust methodology and greater numbers of participants is still required.

Abnormal lactate levels in patients with polymyositis and dermatomyositis: the benefits of a specific rehabilitative program

BACKGROUND

Polymyositis (PM) and Dermatomyositis (DM) are chronic, inflammatory and autoimmune skeletal muscle disorders characterized by reduced muscle strength, fatigue and myalgia. While inflammation causes muscle damage in the early phase, metabolic alterations such as an impairment of oxidative metabolism seem to be responsible for the disability in the chronic phase of the disease.

AIM

To assess muscle oxidative efficiency and to test the effect of aerobic training in a group of PM/DM patients.

DESIGN

A case-control study and a within-group comparison. SETTING. Outpatients of the Unit of Neurorehabilitation of the University Hospital of Pisa.

POPULATION

20 patients with myositis (15 PM and 5 DM) and 15 healthy subjects as a control group.

METHODS

The test consisted of an incremental, sub-maximal aerobic exercise on a treadmill; haematic lactate was assessed at rest and after 1', 5', 10' and 30' minutes from the end of the exercise. A within-group comparison was conducted on four of the PM patients (P group). They were subjected to six weeks aerobic training. Lactate curve and functional tests were assessed before and after the treatment.

RESULTS

A precocious fatigability and significantly higher values of lactate at rest and after the exercise were observed in patients. In the P group mean lactate levels were significantly decreased after the treatment and an improvement of muscle performance was observed.

CONCLUSION

Abnormal blood lactate levels suggested an impaired muscle oxidative efficiency in PM/DM patients. A specific aerobic training program reduced lactate levels and relieved fatigue symptoms in a within-group of four of the PM patients.

CLINICAL REHABILITATION IMPACT

Such a specific aerobic training program could be introduced in everyday practice for the rehabilitative treatment of PM/DM patients.

Strength training and aerobic exercise training for muscle disease

BACKGROUND

Strength training or aerobic exercise programmes might optimise muscle and cardiorespiratory function and prevent additional disuse atrophy and deconditioning in people with a muscle disease. This is an update of a review first published in 2004.

OBJECTIVES

To examine the safety and efficacy of strength training and aerobic exercise training in people with a muscle disease.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (July 2012), CENTRAL (2012 Issue 3 of 4), MEDLINE (January 1946 to July 2012), EMBASE (January 1974 to July 2012), EMBASE Classic (1947 to 1973) and CINAHL (January 1982 to July 2012).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing strength training or aerobic exercise programmes, or both, to no training, and lasting at least six weeks, in people with a well-described diagnosis of a muscle disease.We did not use the reporting of specific outcomes as a study selection criterion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted the data obtained from the full text-articles and from the original investigators. We collected adverse event data from included studies.

MAIN RESULTS

We included five trials (170 participants). The first trial compared the effect of strength training versus no training in 36 people with myotonic dystrophy. The second trial compared aerobic exercise training versus no training in 14 people with polymyositis and dermatomyositis. The third trial compared strength training versus no training in a factorial trial that also compared albuterol with placebo, in 65 people with facioscapulohumeral muscular dystrophy (FSHD). The fourth trial compared combined strength training and aerobic exercise versus no training in 18 people with mitochondrial myopathy. The fifth trial compared combined strength training and aerobic exercise versus no training in 35 people with myotonic dystrophy type 1.In both myotonic dystrophy trials and the dermatomyositis and polymyositis trial there were no significant differences between training and non-training groups for primary and secondary outcome measures. The risk of bias of the strength training trial in myotonic dystrophy and the aerobic exercise trial in polymyositis and dermatomyositis was judged as uncertain, and for the combined strength training and aerobic exercise trial, the risk of bias was judged as adequate. In the FSHD trial, for which the risk of bias was judged as adequate, a +1.17 kg difference (95% confidence interval (CI) 0.18 to 2.16) in dynamic strength of elbow flexors in favour of the training group reached statistical significance. In the mitochondrial myopathy trial, there were no significant differences in dynamic strength measures between training and non-training groups. Exercise duration and distance cycled in a submaximal endurance test increased significantly in the training group compared to the control group. The differences in mean time and mean distance cycled till exhaustion between groups were 23.70 min (95% CI 2.63 to 44.77) and 9.70 km (95% CI 1.51 to 17.89), respectively. The risk of bias was judged as uncertain. In all trials, no adverse events were reported.

AUTHORS' CONCLUSIONS

Moderate-intensity strength training in myotonic dystrophy and FSHD and aerobic exercise training in dermatomyositis and polymyositis and myotonic dystrophy type I appear to do no harm, but there is insufficient evidence to conclude that they offer 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.

Effect of physical training on the proportion of slow-twitch type I muscle fibers, a novel nonimmune-mediated mechanism for muscle impairment in polymyositis or dermatomyositis

OBJECTIVE

To compare muscle fiber type composition and muscle fiber area in patients with chronic polymyositis or dermatomyositis and healthy controls, and to determine whether physical training for 12 weeks could alter these muscle characteristics.

METHODS

Muscle fiber type composition and muscle fiber area were investigated by biochemical and immunohistochemistry techniques in repeated muscle biopsy samples obtained from 9 patients with chronic myositis before and after a 12-week exercise program and in healthy controls. Muscle performance was evaluated by the Functional Index (FI) in myositis and by the Short Form 36 (SF-36) quality of life instrument.

RESULTS

Before exercise, the proportion of type I fibers was lower (mean +/- SD 32% +/- 10%) and the proportion of type IIC fibers was higher (3% +/- 3%) in patients compared with healthy controls. After exercise, percentage of type I fiber increased to 42% +/- 13% (P < 0.05), and type IIC decreased to 1% +/- 1%. An exercise-induced 20% increase of the mean fiber area was also observed. The functional capacity measured by the FI in myositis and the physical functioning subscale of the SF-36 increased significantly. Improved physical functioning was positively correlated with the proportion of type I fibers (r = 0.88, P < 0.01) and type II muscle fiber area (r = 0.70, P < 0.05).

CONCLUSION

Low muscle endurance in chronic polymyositis or dermatomyositis may be related to a low proportion of oxidative, slow-twitch type I fibers. Change in fiber type composition and increased muscle fiber area may contribute to improved muscle endurance and decreased muscle fatigue after a moderate physical training program.

Benefits of intensive resistance training in patients with chronic polymyositis or dermatomyositis

OBJECTIVE

To investigate the benefits and safety of an intensive muscular training program in patients with chronic polymyositis (PM) and dermatomyositis (DM).

METHODS

Nine patients with chronic PM or DM (median age 53 years, range 44-61) were included. Assessments of impairment (10-15 voluntary repetition maximum [VRM], the Functional Index 2 [FI-2], the Grippit, and pain rated on the Borg CR-10 scale), activity limitation (Myositis Activities Profile), and participation restriction (patients' disease impact on well-being) were performed 4 weeks prior to baseline, at baseline, and after 7 weeks of exercise. A 6-item core set of disease activity measures was administered and muscle biopsy samples of vastus lateralis were obtained at baseline and after 7 weeks of exercise. Response criteria at an individual level were set for disability and disease activity. The patients exercised 3 days per week for 7 weeks on loads allowing 10 VRM.

RESULTS

On a group level there were no significant differences between assessments at 4 weeks before baseline compared with baseline. The group improved significantly regarding 10-15 VRM and FI-2 at 7 weeks compared with baseline (P < 0.05). All patients were responders with respect to impairment and 2 were activity limitation responders whereas participation restriction remained unchanged in all. Two patients were responders with reduced disease activity and no patient had signs of increased muscle inflammation in the muscle biopsy sample after 7 weeks of exercise.

CONCLUSION

Patients with chronic, stable PM and DM can perform this intensive resistive exercise program with beneficial effects on impairment and activity limitation without increased muscle inflammation.

Functional outcome and quality of life in adult patients with idiopathic inflammatory myositis

OBJECTIVES

To present the outcome of patients with idiopathic inflammatory myositis, focusing on functional ability and quality of life.

METHODS

Analysis was performed using data from 105 adult patients with definitive polymyositis, dermatomyositis or overlap myositis, who were followed up at a single centre. The diagnosis was made between 1979 and 2000 based on Bohan and Peter's criteria. Functional ability was assessed after a minimum follow-up of 3 yr with the Health Assessment Questionnaire Disability Index (HAQDI) and quality of life was measured with the Short Form 36-item questionnaire (SF-36).

RESULTS

Fifteen patients in our cohort died and 87 participated in the evaluation of functional outcome. Functional ability after a median follow-up of 107.1 months (range 36.4-273.3) was heterogeneous. The median HAQDI score was 0.875 (range 0-2.875). Polyphasic or chronic-progressive disease course, osteoporosis and long-term follow-up were predictive of higher HAQDI scores. In terms of quality of life, significant differences from population norms were shown in all domains of the SF-36. There were no significant differences in the SF-36 scores among the patients according to clinicopathological subset or disease course.

CONCLUSIONS

Although the mortality of our cohort was favourable, myositis continues to have a great impact on life in the medium and long term. The present work indicates that myositis patients have a significantly poorer quality of life than the normal population, but there was no difference among the patients according to clinicopathological subsets.

The benefits and limitations of a physical training program in patients with inflammatory myositis

The clinical features of inflammatory myositis are determined by the severity and extent of muscle weakness and systemic manifestations. The benefits and limitations of physical training programs and rehabilitation strategies depend on the clinical phase of the disease and analysis of underlying impairments responsible for functional limitations in the patient. Patients with early stage disease and severe weakness will be treated differently than patients who have responded to medication and are improving. Not all patients will respond to medications; their therapy programs will have different requirements. This article reviews available data on the physiologic responses to exercise in patients with inflammatory muscle diseases. New data support more aggressive approaches to progressive strengthening exercises for patients with inflammatory myositis.

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.

Benefit of 6 months long-term physical training in polymyositis/dermatomyositis patients

OBJECTIVE

The benefit of long-term physical training in patients with chronic polymyositis or dermatomyositis (PM/DM) was studied prospectively.

METHODS

Eight patients with chronic PM/DM participated in a training programme for 6 months. A group of five PM/DM patients without any physical training was observed for control purposes.

RESULTS

While there was no significant change in serum creatine phosphokinase (CPK) levels, the 'activities of daily living (ADL)' score improved significantly (P < 0.03), peak isometric torque (PIT) generated by muscle groups in the lower extremities rose significantly (P < 0.03) and there was a statistically highly significant increase in peak oxygen uptake (VO2max) relative to body weight (P < 0.02) due to the long-term training. The patients improved their aerobic capacity by 28%, which is clinically significant. In the untrained patients, no improvement in these target parameters was observed.

CONCLUSION

In clinically stable DM/PM patients, long-term physical training can safely be performed and is recommended as part of a comprehensive rehabilitation management, particularly in view of the cardiopulmonary risk in these patients.

Improvement of physical fitness and muscle strength in polymyositis/dermatomyositis patients by a training programme

In the present investigation, the benefit of physical training in patients with inflammatory myopathy was studied. In this prospective, randomized, controlled study, 14 patients with polymyositis (PM) or dermatomyositis (DM) were investigated. The training, consisting of bicycle exercise and step aerobics, took place over a 6 week period. Baseline and endpoint measurements included an 'activities of daily living' (ADL) score, peak isometric torque (PIT) generated by muscle groups in the lower extremities, peak oxygen consumption (VO2max), and creatine phosphokinase (CPK) levels. There was no significant rise in disease activity in the training group in comparison to the controls. The ADL score for the treatment group, in comparison to the control group, improved (P < 0.02), PIT rose (P < 0.05) and there was a statistically significant increase in oxygen uptake relative to body weight (P < 0.05). No rise in inflammatory activity, but significant improvement in muscle strength, oxygen uptake and well-being, were found in patients with inflammatory myopathy as a result of physical training. Besides medication, a physical training programme consisting mainly of concentric muscle contractions should therefore be an integral part of therapy, particularly in view of the cardiopulmonary risk of these patients.

Classification and treatment of the juvenile idiopathic inflammatory myopathies

This article reviews the current status of the classification and treatment of the juvenile idiopathic inflammatory myopathies. The intent of classification is to define homogeneous groups that share similar clinical features, disease courses, and responses to therapy. The classification scheme proposed includes clinicopathologic subsets, serologic subjects based on the presence of myositis-specific and myositis-associated autoantibodies, and environmental triggers of myositis. Juvenile dermatomyositis is the most common and widely recognized of these disorders. The second part reviews the history of treatment of juvenile dermatomyositis and discusses agents to consider for patients with refractory disease, unacceptable steroid toxicity, or poor prognostic factors.

Occupational therapy management of a patient with severe polymyositis

The purpose of this article is to illustrate with a case study the process through which a patient with polymyositis taking part in an occupational therapy program achieved functional improvement in spite of persistent muscle weakness. Although the focus is on the occupational therapy program, close monitoring of patient improvement or regression by the total rehabilitation team was essential in order to adjust the patient's weekly activity level for maximum benefit.

Resistive exercise in the rehabilitation of polymyositis/dermatomyositis

OBJECTIVE

To determine the effect of a resistive exercise program in the rehabilitation of patients with polymyositis/dermatomyositis (PM/DM).

METHODS

Five patients participated in a rehabilitation program that included resistive exercises. In 4 of the patients, these exercises were randomly alternated with nonresistive exercise. Each type of exercise was assigned for periods of 2 weeks, and at the end of each one, muscle strength was measured by means of manual muscle testing (MMT), an activities of daily living (ADL) score, and peak isometric torque (PIT) generated by muscle groups in the lower extremities. Creatine phosphokinase (CPK) levels were used to measure disease activity. The acute response to resistive exercise was studied in 4 of the patients by measuring serial levels of CPK following a session on an exercise bicycle.

RESULTS

Of the 4 patients who participated in both types of exercises, 3 experienced increases in strength during both resistive and nonresistive exercise periods. The patient who participated only in resistive exercises had considerable improvements in muscle strength. One patient made no improvements in strength with either type of exercise. None of the patients experienced clinically significant elevations in CPK attributable to either type of exercise. Following a session of resistive exercise, the mean CPK elevation in 4 patients was 7.7%, returning to pre-exercise levels by 8 h in all cases.

CONCLUSIONS

Patients with PM/DM may participate in a rehabilitation program which includes resistive exercises. Such programs may be accompanied by increased strength without clinically significant rises in serum levels of muscle enzymes.