The notions are a bit vaguely interconnected and the scheme ends up too broad. I studied the link with Parkinson's years ago. I didn't find much pragmatic utility, except for people who stutter being perhaps more likely to develop Parkinson's later in life. Stuttering is characterized by excessive dopamine production, whereas Parkinson's by loss of dopamine-producing cells. It might be that after a lifetime of excessive dopamine production that this loss occurs. This is just an assumption, of course. Movement systems and reward systems is a bit simplistic, and that's why it leads to broad generalizations later on. Fear and anxiety are not properly tackled. Here's a first step: Remove the shame and the stigma from the equation. Stuttering has a traumatic effect on the body nonetheless. When we anticipate a block, our organism predicts a state of oxygen deprivation. Breathlessness. That is bound to create temporary imbalances in O2/CO2 levels, and so the body initiates the "unconscious" physiological response to prepare against it. From a logical standpoint, if we are to improve our ability to handle temporary imbalances in O2/CO2 levels (Carbon Dioxide Tolerance), then the physiological response to anticipation is bound to be milder and produce less stress on the organism. Lifting weights and cardio-based endurance exercises cause an increase in CO2 levels and blood PH tends towards acidic. Talking or reading out loud for prolonged periods of time decreases CO2 levels because we expel more CO2 than the body produces. Blood PH tends towards alkaline. And so in doing both types of activities, you touch both ends of the spectrum and expand your range to become more durable against temporary imbalances. It's not the be-all and end-all, but it's a straightforward way to improve physiological response and experience less anxiety.