Feasibility of resistance training in adult McArdle patients: clinical outcomes and muscle strength and mass benefits

Abstract

We analyzed the effects of a 4-month resistance (weight lifting) training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female) on: muscle mass (assessed by DXA), strength, serum creatine kinase (CK) activity and clinical severity. Adherence to training was ≥84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities’ lean mass (P < 0.05 for the time effect), with mean values increasing with training by +855 g (95% confidence interval (CI): 30, 1679) and +547 g (95%CI: 116, 978), respectively, and significantly decreasing with detraining. Body fat showed no significant changes over the study period. Bench press and half-squat performance, expressed as the highest value of average muscle power (W) or force (N) in the concentric-repetition phase of both tests showed a consistent increase over the 4-month training period, and decreased with detraining. Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining. Importantly, all the participants, with no exception, showed a clear gain in muscle strength after the 4-month training period, e.g., bench press: +52 W (95% CI: 13, 91); half-squat: +173 W (95% CI: 96, 251). No significant time effect (P > 0.05) was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3) after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for disease severity.

Report on the EUROMAC McArdle Exercise Testing Workshop, Madrid, Spain, 11–12 July 2014

“…A case report of resistance training (weight lifting) in an adolescent with McArdle disease was described by Alejandro Lucia (section Strength training exercise in McArdle disease) [13], which was later confirmed by a study on the feasibility and the functional effect of a strength training exercise program in 7 middle-aged adults with McArdle disease [12].…”

“…Strength training in McArdle disease is not usually recommended because of the high associated risk of acute rhabdomyolysis, but at the workshop Dr Alejandro Lucia demonstrated how it is possible for people with McArdle disease to perform this type of exercise without injury [12,13]. The sport scientists advised participants with McArdle disease on how to develop an individualised training program.…”

“…Alejandro Lucia and Alfredo Santalla described their recently published study illustrating the feasibility of weight lifting exercise in middle-aged McArdle patients [12].…”

Exercise and Preexercise Nutrition as Treatment for McArdle Disease

“…No myoglobinuria episodes were reported during or at the end of the program, and he was virtually asymptomatic after the training intervention (9). Santalla et al (38) recently assessed the effects of a weight lifting training circuit program of 4-month duration and light-moderate intensity (two sessions per week), followed by a 2-month detraining period in seven adult patients with McArdle disease (five female patients), on muscle mass assessed by dual-energy x-ray absorptiometry and muscle strength, and serum-CK and clinical severity. Again, no major adverse effects were reported with training, which induced significant increases in total lean mass (which increased by approximately 1 kg), and on performance in bench press and half-squat tests (observed in all participants).…”

“…The effects of supervised resistance exercise have been assessed in a 15-yr adolescent (9) and in 7 middle-age adults of both sexes (38). The adolescent undertook a 6-wk, supervised, weight lifting program of light to moderate intensity (~65%-70% of 1-repetition-maximum (1RM); two sessions per week) (9) and followed the dietary recommendations detailed in Figure 3.…”