Resistance training and aerobic training improve muscle strength and aerobic capacity in chronic inflammatory demyelinating polyneuropathy.

INTRODUCTION: We investigated the effects of aerobic and resistance exercise in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). METHODS: Eighteen CIDP patients treated with subcutaneous immunoglobulin performed 12 weeks of aerobic exercise and 12 weeks of resistance exercise after a run-in period of 12 weeks without exercise. Three times weekly the participants performed aerobic exercise on an ergometer bike or resistance exercise with unilateral training of knee and elbow flexion/extension. Primary outcomes were maximal oxygen consumption velocity (VO2 -max) and maximal combined isokinetic muscle strength (cIKS) of knee and elbow flexion/extension. RESULTS: VO2 -max and muscle strength were unchanged during run-in (-4.9% ± 10.3%, P = 0.80 and -3.7% ± 10.1%, P = 0.17, respectively). Aerobic exercise increased VO2 -max by 11.0% ± 14.7% (P = 0.02). Resistance exercise resulted in an increase of 13.8% ± 16.0% (P = 0.0004) in cIKS. DISCUSSION: Aerobic exercise training and resistance exercise training improve fitness and strength in CIDP patients. Muscle Nerve 57: 70-76, 2018.

High-intensity training in patients with spinal and bulbar muscular atrophy.

OBJECTIVE: Long duration, moderate-intensity exercise is not well tolerated in patients with spinal and bulbar muscular atrophy (SBMA). This study investigated whether patients with SBMA can benefit from high-intensity training (HIT). METHODS: Ten patients with SBMA were randomized to 8 weeks of supervised HIT [n = 5; age = 50 (25-63) years] followed by 8 weeks of self-training or 8 weeks of no training followed by 8 weeks of non-supervised HIT [n = 5; age = 50 (26-54) years]. Training consisted of 2 × 5-min exercise periods with 1-min cyclic blocks of intermittent maximal intensity exercise on an ergometer bike. Maximal oxygen capacity (VO2max) and workload (Wmax) were measured before and after training by incremental exercise tests. Plasma creatine kinase levels, self-rated muscle pain, muscle fatigue, and activity level were monitored throughout the training period. RESULTS: Eight patients completed training. One patient dropped out after 5 weeks of training for private reasons. Another patient was excluded after 4 weeks due to lack of compliance. Eight weeks of training increased both VO2max (1.9 ± 2.3 ml min-1 kg-1; p = 0.04) and Wmax (15.6 ± 17.9 W; p = 0.03) in the 8 patients who completed training. There were no changes in plasma creatine kinase levels, self-reported muscle pain or muscle fatigue activity level after training. CONCLUSION: This pilot study suggests that high-intensity training is safe and improves fitness in patients with SBMA. Unlike low- and moderate-intensity training, HIT is efficacious and favored over other training forms by the patients.

High-intensity interval training in facioscapulohumeral muscular dystrophy type 1: a randomized clinical trial.

Increasing evidence suggests that high-intensity training (HIT) is a time-efficient exercise strategy to improve fitness. HIT has never been explored in neuromuscular diseases, likely because it may seem counterintuitive. A single session of high-intensity exercise has been studied without signs of muscle damage in facioscapulohumeral muscular dystrophy type 1 (FSHD1). We aimed to determine whether HIT is safe and effective in FSHD1 in a randomized, controlled parallel study. Untrained adults with genetically verified FSHD1 (n = 13) able to perform cycle-ergometer exercise were randomized to 8 weeks of supervised HIT (n = 6) (3 × 10-min cycle-ergometer-HIT/week) or 8 weeks of usual care (n = 7). Following this, all participants performed 8 weeks of unsupervised HIT (3 × 10-min cycle-ergometer-HIT/week). Primary outcome was fitness, maximal oxygen uptake/min/kg body weight. Furthermore, workload, 6-min walk distance, 5-time sit-to-stand time, muscle strength, and daily activity levels were measured. Pain, fatigue, and plasma-CK were monitored. Twelve patients completed the randomized part of the study. Plasma-CK levels and pain scores were unaffected by HIT. Supervised HIT improved fitness (3.3 ml O2/min/kg, CI 1.2-5.5, P < 0.01, n = 6, NNT = 1.4). Unsupervised HIT also improved fitness (2.0 ml O2/min/kg, CI 0.1-3.9, P = 0.04, n = 4). There was no training effect on other outcomes. Patients preferred HIT over strength and moderate-intensity aerobic training. It may seem counterintuitive to perform HIT in muscular dystrophies, but this RCT shows that regular HIT is safe, efficacious, and well liked by moderately affected patients with FSHD1, which suggests that HIT is a feasible method for rehabilitating patients with FSHD1.

MRI as outcome measure in facioscapulohumeral muscular dystrophy: 1-year follow-up of 45 patients.

There is no effective treatment available for facioscapulohumeral muscular dystrophy type 1 (FSHD1), but emerging therapies are under way that call for a better understanding of natural history in this condition. In this prospective, longitudinal study, we used quantitative MRI to assess yearly disease progression in patients with FSHD1. Ambulatory patients with confirmed diagnosis of FSHD1 (25/20 men/women, age 20-75 years, FSHD score: 0-12) were tested with 359-560-day interval between tests. Using the MRI Dixon technique, muscle fat replacement was evaluated in paraspinal, thigh, and calf muscles. Changes were compared with those in FSHD score, muscle strength (hand-held dynamometry), 6-minute-walk-distance, 14-step-stair-test, and 5-time-sit-to-stand-test. Composite absolute fat fraction of all assessed muscles increased by 0.036 (CI 0.026-0.046, P < 0.001), with increases in all measured muscle groups. The clinical severity FSHD score worsened (10%, P < 0.05), muscle strength decreased over the hip (8%), neck (8%), and back (17%) (P < 0.05), but other strength measures, 6-minute-walk-distance, 5-times-sit-to-stand-test, and 14-step-stair-test were unchanged. Changes in muscle strength, FSHD score, and fat fraction did not correlate. This first study to systemically monitor quantitative fat replacement longitudinally in FSHD1 shows that MRI provides an objective measure of disease progression, often before changes can be appreciated in strength and functional tests. The study indicates that quantitative MRI can be a helpful end-point in follow-up and therapeutic trials of patients with FSHD1.

Aerobic Training in Patients with Congenital Myopathy.

INTRODUCTION: Congenital myopathies (CM) often affect contractile proteins of the sarcomere, which could render patients susceptible to exercise-induced muscle damage. We investigated if exercise is safe and beneficial in patients with CM. METHODS: Patients exercised on a stationary bike for 30 minutes, three times weekly, for 10 weeks at 70% of their maximal oxygen uptake (VO2max). Creatine kinase (CK) was monitored as a marker of muscle damage. VO2max, functional tests, and questionnaires evaluated efficacy. RESULTS: Sixteen patients with CM were included in a controlled study. VO2max increased by 14% (range, 6-25%; 95% CI 7-20; p < 0.001) in the seven patients who completed training, and tended to decrease in a non-intervention group (n = 7; change -3.5%; range, -11-3%, p = 0.083). CK levels were normal and remained stable during training. Baseline Fatigue Severity Scale scores were high, 4.9 (SE 1.9), and tended to decrease (to 4.4 (SE 1.7); p = 0.08) with training. Nine patients dropped out of the training program. Fatigue was the major single reason. CONCLUSIONS: Ten weeks of endurance training is safe and improves fitness in patients with congenital myopathies. The training did not cause sarcomeric injury, even though sarcomeric function is affected by the genetic abnormalities in most patients with CM. Severe fatigue, which characterizes patients with CM, is a limiting factor for initiating training in CM, but tends to improve in those who train. TRIAL REGISTRATION: The Regional Committee on Health Research Ethics of the Capital Region of Denmark H-2-2013-066 and ClinicalTrials.gov H2-2013-066.