This is the illogic of Parkinson’s…and it is starting to make logical sense to me. Imagine a glass half full of water and by doing, for example, exercise I add water to the glass. Under normal circumstances the volume of water would gradually increase. However, Parkinson’s has a straw and is sucking out the water; therefore to maintain the same level of water requires the same effort that would normally increase the amount. But within Parkinson’s increase means trying to replace what has already gone.