‘Forced’ Cycling May Best Help Those With More Severe Motor Symptoms
Parkinson’s patients who have more severe motor symptoms are more likely to derive a benefit from high-cadence dynamic cycling, an analysis of two cycling studies indicates.
Findings were in the study “Body Mass Index and Exercise Effort Influences Changes in Motor Symptoms After High-Cadence Dynamic Cycling in Parkinson’s Disease,” published in Frontiers in Rehabilitation Sciences.
High-cadence dynamic cycling involves cycling on a stationary bike that is programmed to intermittently quicken pedal speed, “forcing” people to pedal faster than they might otherwise. Some early studies suggest that this form of exercise can help to ease motor symptoms of Parkinson’s, but some patients appear to benefit more than others.
A pair of scientists at Kent State University in Ohio conducted a battery of statistical analyses to look for factors that might make individuals more likely to benefit from high-cadence dynamic cycling.
Data on 31 Parkinson’s patients from two prior studies evaluating this exercise intervention were included in the analyses. Patients were an even mix of sexes, and on average just under 70 years of age. In both studies, participants completed 30-minute sessions of high-cadence dynamic cycling — one study covered three sessions over four days, while in the other patients did six sessions over two weeks.
Motor symptom severity before and after these interventions was assessed using part three of the Unified Parkinson’s Disease Rating Scale (UPDRS).
In addition to demographic factors, such as age and body mass index (BMI, a ratio of weight to height), the researchers assessed the effect of effort on changes in UPDRS scores post-intervention. For this study’s purposes, “effort” was defined by calculating the amount of time that participants were pedaling faster than the bike was “forcing” them to pedal.
Initial analyses confirmed that UPDRS scores overall indicated an easing of symptoms from the start to the end of the interventions. Also of note, effort scores for each participant were consistent across different exercise sessions.
“We … confirmed a significant change in UPDRS scores between the first and last session of each dataset, and no significant changes in effort between sessions. This latter finding lends further support to the idea that effort, defined as the percent of time a participant overtakes the bike motor, is a result of properties intrinsic to each participant and not necessarily to the bike,” the researchers wrote.
Patients with a higher UPDRS score — meaning more severe symptoms — at the study’s start were more likely to experience an easing in symptom severity following the intervention, results showed. Effort, however, was not significantly linked with this change in symptoms.
“The UPDRS model explains 81% of variance in our participants’ post[-intervention] UPDRS scores, with the main significant contributor being baseline [initial] UPDRS scores,” the researchers wrote. “The finding suggests that participants with more severe symptoms are more likely to improve. Effort’s contribution was minimal.”
The scientists also noted a moderating effect between BMI and effort, where individuals with a higher BMI tended to have lower effort scores, as defined by pedaling faster than the bike.
A noted study limitation, according to the researchers, is that their statistical models did not account for changes in heart rate during the cycling intervention due to missing or inaccurate data. They stressed a need for further investigation to determine how high-cadence dynamic cycling might benefit people with Parkinson’s.
“Further testing is needed to decipher the precise relationship between demographic variables, effort, and UPDRS outcome,” the researchers wrote. “By identifying these relationships, it is possible to adapt the high-cadence dynamic cycling prescription to individual characteristics and maximize the outcome.”