Blood Lactate Concentrations With and Without Exercise in Parkinson's Disease and Multiple Sclerosis Patients

Fatigue is one of the most common and debilitating symptoms experienced in Parkinson's Disease (PD) and Multiple Sclerosis (MS). There are multiple proposed mechanisms of disorder-related fatigue, however, it is unknown whether PD or MS patients experience compromised blood lactate responses to an acute bout of exercise, subjecting them to exercise-related fatigue. These populations may experience higher energy expenditure at rest due to increased rigidity, however, limited data exists investigating resting energy expenditure in these populations. Researchers hypothesize that PD and MS patients will display higher resting energy expenditure than healthy age-matched controls, and that level of energy expenditure will correlate with amount of rigidity or spasticity. Also, we hypothesize that baseline levels of lactate will not be different between PD/MS and control groups, but post-exercise blood lactate levels will be significantly higher in the PD/MS groups.