Short- and long-term effects of endurance training in patients with mitochondrial myopathy.

BACKGROUND AND PURPOSE: It is unknown whether prolonged training is a safe treatment to alleviate exercise intolerance in patients with mitochondrial DNA (mtDNA) mutations.

METHODS

The effect of 3 and 12 months training and 3-12 months deconditioning was studied in four patients carrying different mtDNA mutations.

RESULTS

Three-month moderate-intensity training increased oxidative capacity by 23%, which was sustained after 6-12 months of low-intensity training. Training and deconditioning did not induce adverse effects on clinical symptoms, muscle morphology and mtDNA mutation load in muscle.

CONCLUSION

Long-term training effectively improves exercise capacity in patients with mitochondrial myopathy, and appears to be safe.