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

Santalla A, Munguía-Izquierdo D, Brea-Alejo L, Pagola-Aldazábal I, Díez-Bermejo J, Fleck SJ, Ara I, Lucia A - Front Aging Neurosci (2014)

Bottom Line: 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.Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Sports Sciences, Universidad Pablo de Olavide Seville, Spain ; Research Institute "i+12", Hospital 12 de Octubre Madrid, Spain.

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.

No MeSH data available.


Related in: MedlinePlus

Example of strength test (bench press) performed by one of the patients. The Figure shows that the velocity (ms−1) decreases with increasing load (kg), while the average concentric-propulsive power initially increases to a load in which the decrease of velocity is so pronounced that power decreases. The highest average concentric-propulsive power of 73 W occurred at a load of 8 kg.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263173&req=5

Figure 1: Example of strength test (bench press) performed by one of the patients. The Figure shows that the velocity (ms−1) decreases with increasing load (kg), while the average concentric-propulsive power initially increases to a load in which the decrease of velocity is so pronounced that power decreases. The highest average concentric-propulsive power of 73 W occurred at a load of 8 kg.

Mentions: After familiarization with the equipment, participants performed “explosive” leg half-squats on a “Multipower machine”, which was connected to a linear encoder (T-Force Dynamic Measurement System, Ergotech, Murcia, Spain). The latter has previously proven valid to determine force (N) and power (W) (González-Badillo and Sánchez-Medina, 2010). Patients performed 1 set of 3 repetitions at maximum speed with a 2-min recovery period. The load or “resistance” (kg) was increased by 2.5 kg in each successive set. Average muscle force and power output in the concentric-propulsive phase of the repetition were evaluated in each set (Sanchez-Medina et al., 2010). In this type of gradual resistance increase protocol, the developed muscle force increases with resistance, while the velocity of muscle contraction decreases. Power is the product of force × velocity, and initially increases with resistance and then decreases when the resistance causes a substantial decrease in velocity. Thus, the test is stopped when the decrease in velocity is so pronounced that it causes a decrease in average muscle concentric power (see Figure 1 for an example). For statistical analyses we recorded the highest value of average power (W) in the concentric-propulsive phase, which typically coincides with the start of a decline in this variable together with the occurrence of the highest value of average force (N). We also recorded the load (kg) at which maximum average power was generated. The RPE after each set never exceeded the value of 7.


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

Santalla A, Munguía-Izquierdo D, Brea-Alejo L, Pagola-Aldazábal I, Díez-Bermejo J, Fleck SJ, Ara I, Lucia A - Front Aging Neurosci (2014)

Example of strength test (bench press) performed by one of the patients. The Figure shows that the velocity (ms−1) decreases with increasing load (kg), while the average concentric-propulsive power initially increases to a load in which the decrease of velocity is so pronounced that power decreases. The highest average concentric-propulsive power of 73 W occurred at a load of 8 kg.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263173&req=5

Figure 1: Example of strength test (bench press) performed by one of the patients. The Figure shows that the velocity (ms−1) decreases with increasing load (kg), while the average concentric-propulsive power initially increases to a load in which the decrease of velocity is so pronounced that power decreases. The highest average concentric-propulsive power of 73 W occurred at a load of 8 kg.
Mentions: After familiarization with the equipment, participants performed “explosive” leg half-squats on a “Multipower machine”, which was connected to a linear encoder (T-Force Dynamic Measurement System, Ergotech, Murcia, Spain). The latter has previously proven valid to determine force (N) and power (W) (González-Badillo and Sánchez-Medina, 2010). Patients performed 1 set of 3 repetitions at maximum speed with a 2-min recovery period. The load or “resistance” (kg) was increased by 2.5 kg in each successive set. Average muscle force and power output in the concentric-propulsive phase of the repetition were evaluated in each set (Sanchez-Medina et al., 2010). In this type of gradual resistance increase protocol, the developed muscle force increases with resistance, while the velocity of muscle contraction decreases. Power is the product of force × velocity, and initially increases with resistance and then decreases when the resistance causes a substantial decrease in velocity. Thus, the test is stopped when the decrease in velocity is so pronounced that it causes a decrease in average muscle concentric power (see Figure 1 for an example). For statistical analyses we recorded the highest value of average power (W) in the concentric-propulsive phase, which typically coincides with the start of a decline in this variable together with the occurrence of the highest value of average force (N). We also recorded the load (kg) at which maximum average power was generated. The RPE after each set never exceeded the value of 7.

Bottom Line: 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.Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Sports Sciences, Universidad Pablo de Olavide Seville, Spain ; Research Institute "i+12", Hospital 12 de Octubre Madrid, Spain.

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.

No MeSH data available.


Related in: MedlinePlus