Diminished muscle oxygen uptake and fatigue in spinal muscular atrophy.

Objective: To estimate muscle oxygen uptake and quantify fatigue during exercise in ambulatory individuals with spinal muscular atrophy (SMA) and healthy controls.

Methods: Peak aerobic capacity (VO ) and workload (W ) were measured by cardiopulmonary exercise test (CPET) in 19 ambulatory SMA patients and 16 healthy controls. Submaximal exercise (SME) at 40% W was performed for 10 minutes.