Mitochondrial Myopathy

This single-arm pilot study evaluates the effects of whole-body electrical muscle stimulation (WB-EMS) exercise on neuromuscular and physical function in adults with neuromuscular disease (NMD). Due to motor unit impairments, NMD patients often cannot tolerate traditional exercise. WB-EMS bypasses voluntary activation limits by directly stimulating muscle contractions. Up to 50 adults with conditions like ALS, SMA, and MG will undergo 20-minute supervised WB-EMS sessions (1-2 times weekly for 4-8 weeks) using the Katalyst system. Outcomes include neural excitability (TMS), motor unit behavior (EMG, NCS), functional tests (walk, balance, strength), and patient-reported fatigue, pain, and quality of life. Strict safety monitoring and exclusion criteria are in place. This study will provide preliminary data on WB-EMS as a potential exercise modality for NMD.

The goal of this observational study is to learn how exercise training affects molecular processes in skeletal muscle in adults with mitochondrial myopathy, compared with healthy adults. The main questions it aims to answer are: * How does exercise training affect mitochondrial activity and energy production pathways in skeletal muscle in people with mitochondrial myopathy? * How does exercise training affect molecular signals related to muscle growth, stress responses, and muscle-nerve communication in people with mitochondrial myopathy? Researchers will compare the trained leg to the untrained leg within the same participant, and also compare responses between participants with mitochondrial myopathy and healthy control participants, to see how molecular responses to exercise differ between groups. The participants will: * Complete a 3-4-week supervised exercise training program using one leg. * Undergo muscle biopsies from both the trained and untrained leg. * Complete basic muscle strength and physical function tests.