Optimizing Dance Interventions to Improve Motor Function in People with Parkinson'S Disease and Older Adults

seconds and averaged over the minute. Using a mixed linear model to control for within-subject variance, both absolute and relative (percent decrease) M-wave amplitudes for each minute were compared to the first minute of exercise. RESULTS: Subjects exercised for an average of 10 (± 0.7) minutes. V ̇O2, HR, and RPE increased significantly each minute in a linear fashion. Ventilatory threshold occurred at minute 7 (±1 minute). Compared to the first minute of exercise, absolute M-wave amplitude decreased significantly at minute 7 (2.14 ± 2.45mV versus 3.78 ± 2.58mV), whereas relative M-wave amplitude decreased significantly at minute 6 (-20.44% ± 28.53%). After this point, both remained reduced until exhaustion. CONCLUSIONS: These data show that the M-wave may exhibit an excitability threshold corresponding to that of the ventilatory threshold. This could reflect the metabolic state of the muscle, indicating the division between sustainable and unsustainable exercise intensities. Further research should examine the neural response to progressive exercise in relation to peripheral losses of excitability.