We conducted, in persons with Parkinson's disease (PD), a thorough assessment of neuromotor function and performance in conjunction with phenotypic analyses of skeletal muscle tissue, and further tested the adaptability of PD muscle to high-intensity exercise training. Fifteen participants with PD (Hoehn & Yahr stage 2-3) completed 16 wk of high-intensity exercise training designed to simultaneously challenge strength, power, endurance, balance, and mobility function. Skeletal muscle adaptations (p<0.05) to exercise training in PD included: myofiber hypertrophy (type I:+14%, type II:+36%); shift to less fatigable myofiber type profile; and increased mitochondrial complex activity in both subsarcolemmal and intermyofibrillar fractions (I: +45-56%, IV: +39-54%). These adaptations were accompanied by a host of functional and clinical improvements (p<0.05): total body strength (+30-56%); leg power (+42%); single leg balance (+34%); sit-to-stand motor unit activation requirement (-30%); 6-min walk (+43m), Parkinson's Disease Quality of Life Scale (PDQ-39, -7.8pts); Unified Parkinson's Disease Rating Scale (UPDRS) total (-5.7pts) and motor (-2.7pts); and fatigue severity (-17%). Additionally, PD subjects in the pre-training state were compared to a group of matched, non-PD controls (CON; did not exercise). A combined assessment of muscle tissue phenotype and neuromuscular function revealed a higher distribution and larger cross sectional area of type I myofibers, and greater type II myofiber size heterogeneity in PD vs. CON (p<0.05). In conclusion, persons with moderately advanced PD adapt to high-intensity exercise training with favorable changes in skeletal muscle at the cellular and subcellular levels that are associated with improvements in motor function, physical capacity, and fatigue perception.
- Parkinson's disease
- high-intensity exercise
- resistance training
- muscle hypertrophy
- Copyright © 2013, Journal of Applied Physiology