clinical features

Last reviewed 01/2018

  • characterized clinically by recurrent and reversible exercise-induced symptoms of exercise intolerance including ready fatigue, myalgia, cramps, weakness, second wind phenomenon*, myoglobinuria, and hyper CKaemia
    • pain is experienced in everday activities such as chewing, writing, gripping and personal and household chores
    • symptoms are experienced from childhood
  • usually, these symptoms develop in association with intense or sustained exercise
    • however later in life progressive (fixed) muscle weakness may occur

* a ‘second wind’ is usually experienced after 8-12 minutes of gentle aerobic exercise, when free fatty acids and bloodbourne glucose substitute for muscle glycogen and exercise tolerance is increased.