The Science of Showing Up: Why Habit Building Looks Different With a Neurological Condition

If you've ever been told to "just build the habit" and found yourself thinking, easier said than done, you're not being lazy or dramatic. There is an actual neurological reason why habit formation is more difficult when you have Parkinson's disease or multiple sclerosis. And understanding that reason changes everything about how you approach it.

The brain structure responsible for habits is directly affected in PD

Habit formation, the process by which repeated behaviors become automatic, is managed largely by a region of the brain called the basal ganglia. More specifically, a subdivision called the posterior putamen is responsible for habitual, automatic behavior control. In Parkinson's disease, dopamine loss occurs predominantly in the posterior putamen, the very region associated with habitual behavior. This means people with PD may be progressively forced into a goal-directed mode of action control, which is slower, more deliberate, and more cognitively demanding.

In plain language: the brain structure that makes habits feel automatic is the same one most affected by PD. So when a habit doesn't stick, it's not a willpower problem. It's neuroanatomy.

For people with MS, the picture is different but the challenge is real. Fatigue, cognitive changes, and symptom unpredictability all create friction that disrupts the cue-routine-reward loop that habit science depends on. Motivation fluctuates. Energy fluctuates. The day you planned to exercise is often not the day your body cooperates.

Why repetition, not intensity, is the actual mechanism

Here's where the research gets genuinely encouraging. Consistent physical activity promotes the release of brain-derived neurotrophic factor (BDNF), a key protein that supports neuronal survival, growth, and synaptic plasticity. BDNF is essentially fertilizer for the nervous system. It supports the connections your brain is trying to maintain and build.

A 2024 systematic review and meta-analysis published in Brain Sciences looked specifically at exercise and BDNF in people with Parkinson's disease. The pooled analysis of five randomized clinical trials found a significant effect of exercise on BDNF levels, with improvements also seen in motor function measures including the UPDRS-III and Berg Balance Scale.

The critical piece is the word "consistent." Research has shown that discontinuing exercise, even for six months, results in regression of benefits. The nervous system responds to repeated input over time. One excellent session followed by three weeks off does not move the needle the way three modest sessions per week, sustained over months, does. This is not about crushing it. It's about showing up.

What the research says about actually sticking with it

Knowing exercise helps is not the same as doing it. Research on exercise adherence in people with Parkinson's has found something important: personal factors such as poor outcome expectation and low self-efficacy are stronger predictors of exercise adherence than disease severity. The barrier is often not the disease itself. It's belief about what's possible.

A 2024 randomized feasibility trial on behavioral change interventions for people with PD identified several effective components: behavioral regulation, belief about capabilities, and social influences were among the most impactful domains for improving exercise adherence.

What this tells us is that the how matters as much as the what. Structure, external accountability, and specific planning outperform generic motivation every time.

Two things you can do this week

1. The first is implementation planning. Instead of telling yourself "I'll exercise more," decide exactly when, where, and what you will do. Research consistently shows that specific if-then planning (if it is Tuesday morning, then I will do my 15-minute routine before breakfast) dramatically increases follow-through, particularly in populations with executive function challenges. Vague intentions dissolve. Specific plans hold.
   

2. The second is anchoring. Attach your movement practice to something you already do without thinking: your morning coffee, brushing your teeth, a show you watch every evening. The goal is to reduce the number of decisions required before you start. In a nervous system that has to work harder to automate behavior, fewer decision points mean less friction.
   

Neither of these requires a perfect day, a good symptom day, or high motivation. They require only a cue and a short window of time.

The bottom line

Habit building in neurological conditions is not harder because you aren't trying hard enough. It's harder because the neural architecture that automates behavior is directly affected. That's not a limitation to work around by wanting it more. It's a reason to build smarter systems, work with a specialist who understands the neuroscience, and give yourself grace for the days when even the small thing is hard. You are not failing at habits. You are building them in a more challenging environment than most habit advice was designed for.

If you are living with Parkinson's or MS and want support building a movement routine that is realistic, evidence-based, and designed for your nervous system, we would love to connect. Reach out to us here or book a free discovery call to talk about where you are and what might be possible.