Author(s): DERMO, A., ROTONDO, R., DI LIBERO, T., D'ALESSANDRO, G., DE PANDIS, M.F., RODIO, A., Institution: UNIVERSITY OF CASSINO: UNIVERSITA DEGLI STUDI DI CASSINO E DEL LAZIO MERIDIONALE, Country: ITALY, Abstract-ID: 2071

INTRODUCTION:
In Parkinson’s disease (PD), high-intensity aerobic exercise is increasingly prescribed; however, disease-related alterations in autonomic regulation, ventilatory control and cardiovascular dynamics may influence physiological responses during prolonged effort. This case study aimed to investigate metabolic, ventilatory, autonomic and endocrine adaptations to short-term high-intensity aerobic training in a physically active older adult with PD.
METHODS:
A 72-year-old male with idiopathic PD (Hoehn & Yahr stage II), physically active at baseline, completed a 4-week high-intensity aerobic training program (5 sessions/week). Metabolic, ventilatory and cardiovascular variables were assessed during three standardized exercise sessions (baseline, week 2, endpoint) using a portable metabolic analyzer. Each session consisted of 45 minutes of continuous treadmill walking (5Km/h, 1% slope), preceded by a 3-minute warm-up and followed by a 5-minute cool-down. Endocrine adaptation was evaluated through circulating insulin-like growth factor 1 (IGF-1) after the training period.
RESULTS:
Marked physiological adaptations were observed despite stable functional status. Measured energy expenditure exceeded Compendium-predicted values by +47% at baseline, +35.8% at week 2 and +15% at endpoint, confirming the elevated metabolic cost of exercise in PD. Oxygen consumption (V̇O₂) progressively decreased with training, reaching −22% at endpoint, indicating improved aerobic efficiency. Despite this adaptation, respiratory exchange ratio (RER) values were altered at endpoint. During the late phase of exercise (from the 30th minute onward), an increase in respiratory frequency (+3% breaths·min⁻¹) occurred without a concomitant rise in V̇O₂, alongside evidence of cardiovascular drift. This dissociation suggests the presence of relative hyperventilation. Such a response may reflect altered central control of ventilation and late sympathetic activation during prolonged effort, mechanisms potentially amplified by autonomic dysfunction commonly observed in PD. In addition, chronic adaptations included a 9% increase in circulating IGF-1 levels.
CONCLUSION:
Short-term high-intensity aerobic walking elicited relevant metabolic and endocrine adaptations in PD. However, prolonged exercise was characterized by altered ventilatory regulation and cardiovascular drift, highlighting the role of autonomic and central mechanisms. Integrated metabolic, ventilatory and cardiovascular monitoring may be essential to optimize high-intensity exercise prescription in Parkinson’s disease.