Sunday, October 1, 2017

Speed-Based Interval Training for PD

Featured Paper:

This is our first post to the Shake It Off  blog where we will review scientific papers about exercise for people with Parkinson’s disease (PD). The research in this post was supported by ShakeIt Off and their generous friends.  If you ran in the Philly Rabbit Run on Easter weekend, or if you rode in the Shake Off theHills Challenge in the Fall, or if you donate time or money in other ways, you made this research possible. Thank you!  

This is also an exciting post to write because the research was conducted in my (CA Knight, PhD) research laboratory at the University of Delaware with two enjoyable colleagues who have since moved on to continue their scholarly work at other institutions.

Research model
Human: 14 volunteer subjects from local support groups.  Tested before and after 6-week exercise program.  Testing and exercise were performed while subjects were following their normal routines for symptom management (e.g. on medication).
Speed-based interval training on a stationary bike.  Two 30-minute sessions per week for six weeks. See more at this link: SpeedGeezer Training
The exercise program was well-tolerated by all participants.  Significant improvements were observed in many variables: Fast pedaling cadence during exercise, the UPDRS-III score as well as the bradykinesia sub-score, timed tests of whole body mobility, reaction time and the nine-hole peg test.

What is SpeedGeezer?

You won’t find the word “SpeedGeezer” in the related paper but this is what we affectionately call the exercise program.  We originally designed SpeedGeezer to help older adults to fight age-related slowing.  For a related paper see: High-Speed CyclingIntervention Improves Rate-Dependent Mobility in Older Adults

While conducting the first studies, we became interested in Parkinson's disease (PD) and the symptom of bradykinesia (slow movement).  We wanted to learn how speed-based exercise could be used to improve the function of the nervous system in people with PD.  We also sought to provide scientific evidence to support an exercise approach that is practical and accessible  to this population.  These were some of our considerations in the design of SpeedGeezer:

  1. Targeting people in the early stages of PD.  Good science requires focused work that is well-supported by the expertise of the research team.  Among people with PD, our intentional focus is on individuals who have good enough mobility and cognition to get to an exercise facility or exercise safely at home and perform their exercise without mechanical assistance (voluntarily).  Some of you might be familiar with devices such as the Theracycle which have motors to help you pedal. This type of equipment might be appropriate for people in later stages of disease progression.  Other exceptional research teams have demonstrated benefits of this active-assisted exercise in PD but our focus is on exercise that is not-assisted by the equipment.  Our present findings support the benefits of voluntary speed-based exercise. 
  2. Training the Brain. Even though we chose bicycle exercise for this study, we believe that other fast movements will work too.  This exercise program uses fast bicycling with the legs in order to train the brain.  PD is a brain problem, not a legs problem.  During speedwork exercise, the brain has to deliver well-timed busts of electrical excitation to all the working muscles.    You can find more details on SpeedGeezer Training at this link, and substitute a different movement of your choice if necessary.  One former research participant used a treadmill to do the SpeedGeezer exercise routine at home.
  3. Avoid Soreness in New Exercisers: Some people with PD are new to exercise or have not exercised in a long time.  Even among people who exercise regularly, fast or powerful movements are less commonly practiced.  This is why we insist on using the lowest (easiest) resistance settings on the bike.  Pedaling fast without resistance might seem awkward or annoying but it requires you to improve the smoothness of your pedaling motion.  If you find yourself 'shaking the bike apart' you should a) slow down, b) focus on smoothness and then c) try to speed up again.  Improving your coordination may provide other benefits through the processes of motor learning.  The exercise session might still seem challenging, but it is designed to minimize the risk of muscle soreness and joint pain.  When you graduate from SpeedGeezer, you can increase your pedaling resistance in a sensible progression. 
  4. Minimize Fall Risk: A stationary recumbent bicycle with an open step-through area has minimal fall risk. See 'What kind of bike?' for more detail on bike selection.
  5. Availability of Equipment: We want to train people with equipment that they can find and use after their involvement in our research ends.  These bikes are easy to find in exercise facilities, can be purchased for the home, and do not require technical assistance for use.
  6. Intervals help manage cardiovascular risk: Some people with PD also have other health conditions that need to be managed during exercise.  The rest periods between the intervals of fast pedaling allow heart rate and blood pressure to recover towards resting levels.  We can increase the duration of rest periods between intervals or reduce the number of intervals to keep a person exercising at a safe intensity. 
  7. Intervals provide practice with motor-switching: We believe that practicing the pattern of SLOW-FAST-SLOW-FAST… in the exercise program will help fight some of the other motor difficulties such as freezing of gait (FOG, see this paper).  We did not test this hypothesis in the present study but we have seen some subjects improve their ability to switch from slow pedaling to fast pedaling throughout the SpeedGeezer program.  This practice of motor switching would not happen if you pedaled fast continuously for 20 minutes.  Also, people can achieve higher peak pedaling speeds during short intervals.  If you want to mix things up and if your bike allows it, try switching to backwards pedaling.
Are we really training the brain or just the legs?  As a responsible scientist, I have to state that this study would provide stronger evidence if we had a control group of people with PD who did not exercise.  The fact that this group of people is becoming harder to find suggests that the message about the benefits of exercise is spreading!  Despite this limitation of the study, we are encouraged by the significant improvement in the 9-hole-peg test which is a timed test of hand dexterity.  In our ongoing research, we are interested in how fast exercise involving the legs can improve physical performance in the arms and hands as well as cognition.  If this pattern of transferred benefits emerges in multiple studies, we will have greater confidence that this exercise is affecting the brain.  However, the benefits of physical activity on cognition are already well supported by science: PubMed Search.

Is the speed-based interval training studied here the same as High Intensity Interval Training (HIIT)?    Read more at this post…

The First Step for Beginning Exercise

Historically, fast, high intensity or high power exercise strategies have not been recommended for older adults and patients.  These exercises have been avoided mainly to minimize cardiovascular and musculoskeletal risks.  We are beginning to understand the tremendous benefits of high power and high intensity exercise in various patient groups but we still need to apply such exercise strategies with caution.  In 2015, the American College of Sports Medicine (ACSM) updated its approach to Pre-Participation Health Screening to minimize the risks of exercise without creating unnecessary barriers to exercise participation.  Click here if you are interested in best-practices for screening.

Before you begin an exercise program, take a fitness test, or substantially increase your level of activity, make sure to answer the following questions. This physical activity readiness questionnaire (PAR-Q) will help determine if you’re ready to begin an exercise routine or program.
  • Has your doctor ever said that you have a heart condition or that you should participate in physical activity only as recommended by a doctor?
  • Do you feel pain in your chest during physical activity?
  • In the past month, have you had chest pain when you were not doing physical activity?
  • Do you lose your balance from dizziness? Do you ever lose consciousness?
  • Do you have a bone or joint problem that could be made worse by a change in your physical activity?
  • Is your doctor currently prescribing drugs for your blood pressure or a heart condition?
  • Do you know of any reason you should not participate in physical activity?
If you answered yes to one or more questions, if you are over 40 years of age and have recently been inactive, or if you are concerned about your health, consult a physician before taking a fitness test or substantially increasing your physical activity. If you answered no to each question, then it’s likely that you can safely begin exercising, according to these guidelines provided by the ACSM.

What are the Side Effects of exercise?

Some people with PD have momentary drops in their blood pressure.  Be careful when you rise from the bike after exercise.  Take it slow.  Other than this, exercise sometimes comes with some reversible fatigue and some soreness.  If you keep taking this wonderful medicine called exercise, these side effects will likely diminish.  Then there are all the good side-effects of exercise: improved heart health, reduced depression and anxiety, improved bone health and more.  The side effects of exercise, if you want to think of them that way, are mostly good.