On Dec. 30 Lab Rat posted a thread titled "Interval Training relieves PD symptoms". If I'm reading the article correctly, the researchers found that: "CONCLUSION: Training-induced alleviation of parkinsonian rigidity and muscle tone decrease may be associated with neuroplastic changes caused by a training-induced increase in the level of brain-derived neurotrophic factor." Is it possible that high intensity cycling can increase GDNF enough to be significant for PwPs? What would that actually mean for our symptoms?