Exercise as it relates to Disease/The effect of exercise training in improving motor performance and corticomotor excitability in people with early Parkinson’s

What is the background to this research?
This paper aims to understand the relationship between exercise and its effect on improving motor performance and corticomotor excitability in people with early Parkinson's. This is important as it can be used as a treatment in these people, to improve their quality of life and prevent the disease from rapidly intensifying.

Where is the research from?
This research was conducted in the USA. Most of the authors of this research have previous experience researching a relevant aspect included in this research (motor control, corticomotor excitability and/or Parkinson's disease). There are no organisational/sponsorship links that may be a conflict of interest/bias to the findings in this research.

What kind of research was this?
This study was in the form of a cohort (prospective) study. Within this cohort, a randomised controlled trial was conducted in order to gain valid results.

The results found in randomised controlled trial are acknowledged as the highest quality of research testing, this is due to participant and researcher bias.

What did the research involve?
With their eyes closed each participant chose a card grouping them into one of three groups (high intensity exercise, low intensity exercise and no exercise). The participants in the exercise groups received 24 exercise sessions to be completed over 8 weeks. The high intensity group aimed to walk on a treadmill at > 3.0 METS for 45 minutes, rest was permitted if necessary. The low intensity group consisted of 45 minute sessions, in each session there were six activities, these were; (1) passive ROM and stretching, (2) active ROM, (3) balance activities, (4) gait, (5) resistance training, and (6) practice of functional activities and transitional movements, the goal was to keep METS level at 3.0 or less. The zero intensity group participated in six 1 hour educational classes over the 8-week program. All participants were to keep an activity diary for exercise completed outside of the planned study sessions. I believe this methodology was the best approach in order to achieve valid results. Although, some limitations include the small sample size and a large variability in the severity of each participants disease and baseline motor performance.

What were the basic results?
The high intensity group exhibited improved gait parameters and kinematics of gait performance, however, this was not consistently replicated in the two other exercise groups. All of the participants across all of the exercise groups exhibited improvement in gait velocity. High intensity exercise group lengthened the cortical silent period (CSP), however this was also not replicated in the other exercise groups. Thus concluding that rather than exercise in general having an effect on the motor control and corticomotor excitability in persons suffering from early Parkinson's, the intensity of the exercise being performed is the main factor. The exercise must be performed at a high intensity for there to be a positive effect on the participant.

What conclusions can we take from this research?
Exercise does have an effect on motor performance and corticomotor excitability. However, in order for this effect to take place, the exercise has to be done at a high intensity - > 3.0 METS.

The results from this research are re-enforced by the findings of Xu, where stated that exercise can reduce the side effects of Parkinson's disease. They are also enhanced by Shu, where it is stated that the the evidence suggests aerobic exercise improves the motor performance of people suffering with Parkinson's disease. Thus concluding that the results found by this study are valid and align with the findings of other recent relevant studies.

Practical Advice
This research identifies high intensity exercise as a tool in improving motor control and corticomotor excitability in people suffering from early Parkinson's disease. In particular, walking on a treadmill. Reaching > 3.0 METS (high intensity), for 45 minutes, breaks can be taken if necessary for health and safety reasons. Even though the results of this research are encouraging, i would still advise consulting with an exercise physiologist to develop an exercise program appropriate for the health and safety of the individual.

Further information/resources
More information that the reader may benefit from may be found:

Parkinson's Disease

 * https://www.healthline.com/health/parkinsons
 * https://www.parkinson.org/understanding-parkinsons

Motor Control

 * https://exercise.trekeducation.org/principles/motor-control/
 * https://www.encyclopedia.com/sports/sports-fitness-recreation-and-leisure-magazines/motor-control

Corticomotor Excitability

 * https://www.frontiersin.org/articles/10.3389/fnhum.2020.00190/full
 * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363483/