Can Specific Exercises Improve Specific PD Symptoms?
- Stephanie Soto
- Apr 27
- 3 min read
A recent study published in the Journal of Movement Disorders looked at the specific effects of Tai Chi, strength training, yoga, or home-based exercise on PD symptoms. Let's see what they found.
This study was a multicenter study, meaning multiple different clinics conducted the study. This helps cast a wider net for the results and help reduce risk of bias. The study was also an open-label study, meaning people who participated in the study knew what group they belonged to. Typically, we want everyone involved to be blinded to reduce the risk of bias. However, with studies that involve exercise, it is impossible for the participants to be blinded. The people who perform the tests to track progress should have been blinded, but were not. This means people who were testing the subjects after the intervention could be biased to one group versus the other and without realizing, could collect the data in a way that supports their bias. The study was also a randomized control trial meaning that each participant was randomly chosen for each intervention. This is hugely important to reduce any risk of bias.
A total of 99 people were included in the study. Individuals must have been between 40 and 80 years old, diagnosed with PD, and able to walk independently. People who were at a risk of fall during exercise, had other conditions that impacted their balance, had dementia, took medication for depression, or had motor fluctuations were not allowed to participate. That last part is important. Many people with PD have motor fluctuations, so the results of this study may not be applicable to many of you.
The study was conducted for 24 weeks, 12 weeks with supervised sessions and 12 weeks with independent practice. At the end of the study, several physical tests and questionnaires were used to assess possible progress.
Unfortunately, the study did not include exactly what they did in each group. This is a frequent fall back with most research around exercise. Researchers rarely include a in-depth description on what they did. Often when they do include it, the exercises chosen does not match the intended stimulus. For example, this study had a group for strengthening. The authors included that the intensity for strengthening was an RPE of 13-15, which would be wonderful for hypertrophy based training. For strengthening, an RPE of 16-18 is needed. There was no information on how many sets and reps were completed. Unless 5 sets of 5 reps with a 2 minute rest break was included, you cannot claim that you were doing strengthening exercises. Exercise is highly specific. There has been hundreds if not thousands of research studies demonstrating that specific sets and reps should be completed if you want to strengthen, make your muscles bigger, or make your muscles have more endurance. However, this rarely gets implemented into research studies like this one.
The results of the study concluded that home exercise and tai chi improved motor symptoms and a walking test, while strengthening and yoga improved balance. However, I do not think what the authors concluded paint an accurate picture. Below is a picture of their results section.
When you look at the first group of numbers for home exercise, it appears like there was significant improvement. The number started at 31 and ended at 20. However, those pluses and minuses next to it means people scored anywhere in that range. That is called a confidence interval. When the baseline results confidence interval (17 to 45) fall within the confidence interval of the results at the end of the study (8 to 32), the results are not as promising at they look.
You also want to compare results between groups. This helps show if one intervention was more helpful than the other. When you look at the results and the confidence intervals for the MDS-UPDRS part III for each intervention, they all fall within the same range. This means there was not meaningful change between groups.
I know this is a lot to take in. Research is really complicated and this is something that I still don't feel that proficient in. When you are reading research studies, look at their actual results, not just what the authors concluded. In this case, even though the authors concluded there was certain exercises that helped certain symptoms, I do not think that is what the actual data of their study showed.
What is my opinion on if specific exercise helps specific symptoms?
Specificity is where the magic lives. If you cannot get out of a chair because you are not strong enough, you need strengthening exercises. If you are falling a lot, you need balance exercises. If you cannot walk long distances because you get tired, you need endurance exercises. However, the best exercise is the one that you will actually stick with! Consistency is key.
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