The purpose of this study is to explore the relationships of exercise on inflammation in the body of older adults and people with Parkinson's disease (PD). This is important research for older adults but is especially important for people with PD because neuroinflammation is the main pathological mechanism that is responsible for neuron cell death in this neurodegenerative disease. As PD is a progressive disease, halting or slowing the degeneration is an important research target. Halting or slowing the disease progress is known as neuroprotection. Exercise is an attractive therapeutic treatment for people with PD as it has a lot of multi-systemic benefits, but also there is a lot of evidence to suggest that it helps improve symptoms and slow the progression of the disease. Exercise has been theorized to decrease inflammation and, therefore, has a lot of promise as a neuroprotective agent in slowing or halting the degeneration in PD. Unfortunately, there is not a lot of research that has looked into the effect of exercise on the biological processes of inflammation. Thus, the purpose of this study is to investigate the biological evidence that underlies the positive effect of exercise in people with PD.