This study looks at how visual feedback from the SpiroGym mobile app affects breathing exercises for people with Parkinson's disease. Parkinson's disease is a condition that affects movement and can make muscles weak. Expiratory Muscle Strength Training (EMST) helps make breathing muscles stronger. In this study, participants will do breathing exercises twice. Once with feedback from the app and once without. Visual feedback means seeing how well you're doing on the app, which might help you try harder.

• The study lasts for two weeks with two sessions of training.
• Participants need to have Parkinson's and stable medication.
• People with other brain disorders or certain health issues can't join.

Surface Electromyography (sEMG) is a test to measure muscle activity. The study will check if seeing feedback makes muscles work harder. If you're interested and meet the criteria, this study might help improve your breathing strength with Parkinson's.