He was diagnosed with McArdle disease at the age of 20 years based on an abnormal muscle biopsy.
His serum CK level varied as expected in McArdle disease, with a decreasing trend (average CK in 2011-2014: 3,006 IU/L, average in 2015-2017: 1,029 IU/L; last measured in July 2017: 941 IU/L; reference range: up to 240 IU/L).
Here we report two people with McArdle disease who have safely performed resistance training.
Owing to the risk of recurrent rhabdomyolysis, for many years resistance training was strongly warned against in people with McArdle disease. The first case report suggesting a safe protocol of resistance training in McArdle was published in 2013 in Spain [6].
He initially followed the guidance of a local personal trainer, who learnt about McArdle disease and understood the underlying disease pathophysiology.
Considering that the ATP-phosphocreatine energy system pathway is not affected in people with McArdle disease, we have demonstrated in our small case series that this population can safely exercise at a high intensity level for up to 10 seconds at time, depending on training intensity, with 30 seconds to 3 minutes break in between sets of exercise in order to allow energy to be restored.