Parkinson’s & Exercise: The SPARX Trial
Correction: A friend of mine, and creator of the Eatiquette app, emailed me after reading this post to clarify some issues on heart rate. Note, heart rate CAN be tested physically, and the calculations are a guide to help people guestimate. Plus, testing maximum heart rate physically is NOT advisable for the general public. My friend, Wiets, measured her heart rate physically when she was 17 and on the national rowing team; her max heart rate was 220! She also provided me with a link to a post on the Athlete Blog all about the different ways to measure heart rate, check it out here and expect some future posts on heart-rate here on the Quick Bites website!
Diagnosing PD
A dear friend of mine was recently diagnosed with Parkinson’s Disease (subsequently referred to as PD). Prior to his diagnosis, I wrongly assumed that PD was diagnosed with a blood test or some other definitively biological method. However, PD is diagnosed based on symptoms as well as ruling out other ailments. A few of the cardinal symptoms of PD present as tremors, bradykinesia (slowness of movement), stiffness/rigidity, and/or postural imbalance.
Another symptom that can accompany early-stage PD is losing one’s sense of smell. This under-recognized symptom was experienced by my friend nearly 5 years before his diagnosis. A PD diagnosis can take years. Oftentimes, a PD diagnosis is confirmed by seeing whether or not symptoms significantly improve after taking a prescribed PD medication.
Exercise & PD
Another incorrect assumption I had about the disease was that people with PD could not, and should not, partake in strenuous physical activity. You will soon see how wrong I was! Beyond giving hugs and baking cookies, I felt at a loss about how to help my friend. So I decided to dig into the research for evidence-based strategies that he could put to use straight away.
I was less interested in the causes and risk factors for PD, and was more interested in non-invasive treatments such as nutrition and exercise. In my search I came across an article published in the journal JAMA Neurology in February 2018 titled:
“Effect of High-Intensity Treadmill Exercise on Motor Symptoms in Patients With De Novo Parkinson Disease - A phase 2 Randomized Clinical Trial.” (1)
The SPARX Trial
The authors of this study referred to it as “The Study in Parkinson’s Disease and Exercise,” cleverly abbreviated to the acronym SPARX.
The SPARX study indicates it is safe and feasible for early stage (de novo) PD patients to exercise at high-intensity (80-85% max heart-rate) 3 days a week.
This dose (intensity) and frequency (days a week) of exercise may delay worsening of PD progression, specifically in regards to motor skills.
High-intensity exercise three times a week was also shown to significantly improve Vo2 rates (oxygen absorption).
While these are all promising results, more research is needed on exercise dose and frequency as it relates to PD symptoms, and the findings from the Phase 2 SPARX trial indicate further research IS warranted.
Notice how the researchers use terms we often relate to medication, ie “dose” and “frequency,” to describe exercise. This is a reminder that exercise, like medicine, can be prescribed to treat diseases.
The SPARX Highlights
I recommend anyone who is interested to read the full article. You can also email me for a comprehensive analysis, written in easy to understand laymen’s terms, of the study’s design, methods, and results. But for now, let me highlight a few important points of the study.
This was a well designed single-blinded (the researchers were blind to what treatment the participants were receiving which helps reduce bias) randomized controlled trial where the results of two groups of exercisers (moderate-intensity and high-intensity) were compared against each other as well as against a control group of folks who were not prescribed an exercise regime.
The participants, at enrollment, were not on any dopaminergic drugs. (Dopaminergic drugs are medications that release serotonin and are commonly used to treat PD and psychiatric issues). This is important because if you did this study but included people on meds, it would be difficult to tell whether or not the results were associated with the exercise or the meds, so the researchers removed people on meds entirely.
One of the most important messages of the study’s authors was that high-intensity exercise is SAFE and FEASIBLE for early stage PD patients.
In the past, the medical community had been reserved about recommending high-intensity exercise to people with a neurodegenerative disease that affects the muscles.
The results of the SPARX trial determined that beyond the expected muscle and joint soreness, it was safe for early stage PD patients to exercise three times a week at high-intensity. One limitation of the study, however, was that the authors did not go into further detail about 9 (20.9%) people in the high-intensity group who experienced “adverse events related to exercise with a severity greater than mild.” All participants were evaluated by a cardiologist before starting this program, something that anyone with a condition should consider before starting any exercise program.
Determining that it was “feasible” for early-stage PD patients to exercise at high-intensity, 3 times a week for 6 months showed that the participants COULD do it - that it was a practical intervention. The mean frequency rate for the high-intensity exercise group was 2.8 days per week, and the mean frequency rate for the moderate-intensity group was 3.2 days per week. Remember, “mean” is the average, so some folks were exercising more than that, and some less than that.
4. This was the first study to specifically research the effects of high-intensity exercise on symptoms of PD.
5. The results of the SPARX trial showed that high-intensity exercise 3 times a week had a significant beneficial effect on motor skills. The motor skills did not improve, but more importantly they did not worsen. In degenerative diseases it is often the goal to maintain or retain skills (delay worsening), as opposed to improving them. Other characteristics that were measured, but saw no significant effect from exercise were mental activity, mood, behavior, and “activities of daily living.”
6. One of the limitations of the study, as cited by the authors, was that it was specific to a treadmill. Hopefully future studies will research the effect of high-intensity exercise beyond a treadmill. Just imagine a study that measures the beneficial effects of high-intensity sex! Anything is possible, but it must always pass an institutional ethics board first.
Heart Rate Monitors
One of the most interesting and applicable pieces of information I took from the SPARX study was the importance of objectively measuring heart-rate.
We are often told to measure our exertion (low-, moderate-, or high-intensity) by how easily we can speak or sing while exercising. These types of measurements are subjective and susceptible to imperfection.
What the SPARX trial showed is that if you want to truly know the intensity you are exercising at, it should be measured with an objective tool like a heart-rate monitor.
So, I bought a heart-rate monitor! As did my friend with PD! The heart-rate monitor and the accompanying Polar app are easy to use, but understanding maximum heart-rate and intensity is a little trickier.
Understanding Maximum Heart-rate
When the SPARX trial referenced 80%-85% maximum heart-rate, I thought that meant the person got their heart-rate up to the highest it would go, and then calculated the 80-85% number from there.
Hahah, I was SO wrong.
Apparently, your maximum heart rate is determined by a calculation, not necessarily by your own individual heart!
You calculate your maximum heart-rate by subtracting your age from 220.
So my maximum heart-rate would be 174bpm (beats per minute)
[220 - my age of 46 = 174].
See this screenshot from my Polar heart-rate monitor app and you will see my max heart-rate was already calculated for me based on my age.
According to the Mayo Clinic, your maximum heart-rate “is the average maximum number of times your heart should beat per minute during exercise.” (Emphasis added). Your calculated maximum heart-rate is an average, which means you will be both under and over that number at times.
You can see an example of this from the screenshot to the left where my actual heart-rate reached 180bpm; 6 beats over my calculated average max heart-rate.
To make things even more confusing, this isn’t the only way to measure max heart-rate. That’s for another post, but if you are older and/or very fit, there are other more accurate calculations you can use.
How to Measure Intensity
So now that we’ve got our maximum heart-rate, how do you figure out your intensity?
There’s no one universal recommendation or definition for what constitutes moderate- or high-intensity exercise, but generally speaking if it’s above 75% of your maximum heart-rate, you’re getting into the high-intensity zone.
There are a couple of ways to calculate your target heart-rate zone. The easiest is to take your maximum heart-rate and multiply it by the percentage of your max heart-rate you want to meet.
If you want to figure out 85% of your max heart-rate, multiply your max heart-rate by 0.85.
174 (my max heart-rate) x 0.85 = 147.9 bpm (85% of my maximum heart-rate)
Another way to calculate this is by using the heart-rate reserve (HRR) method.
For this calculation, you subtract your resting heart-rate from your max heart-rate, multiply it by your target percent then add back your resting heart-rate.
Resting heart-rate is your beats per minute when totally calm and relaxed, i.e. when you first wake up in the morning. Resting heart-rate is usually between 60 and 100 bpm for adults; the fitter you are, the lower your resting heart-rate usually is.
The calculation looks like this:
174 (max heart-rate) - 62 (my resting heart-rate) = 112
112 x 0.85 (target intensity percentage) = 95.2
95.2 + 62 (my resting heart-rate) = 157.2 bpm
As you can see from my training sessions recorded on my Polar app, I was exercising within and above 85% of my maximum heart-rate.
These calculations are good guides, but there are no hard and fast rules you should adhere to, except for the rule to talk with your physician first. Also, some medications, especially blood pressure meds, can affect heart-rate, so take that into consideration as well.
Futile or Non-Futile?
The SPARX trial was what is referred to as a “futility study.” I had never heard of a futility study before, but it provides an important way to test whether or not it is useful to conduct more research on a topic.
Specifically, researchers conduct a small trial to see if there are any significant results from a certain treatment. If so, then it is “non-futile” to conduct future research such as a 3rd phase, but if there are NOT any significant results from the treatment, then it would be deemed “futile” to conduct any future phases of research. Assessing the futility/non-futility of a trial ensures money, time, and human resources are spent efficiently.
Additionally, this trial was important because while prior studies had shown improvement in PD symptoms with moderate-intensity exercise, there hadn’t been any studies yet that were specific to high-intensity exercise. Since exercise requires more effort and commitment on the part of the patient than medicine does, it was imperative to the researchers that they assess the safety, feasibility, and most effective “dose” of exercise (i.e. intensity) before conducting future research such as Phase 3.
SPARX Phase 3
The outcome of Phase 2 of the SPARX trial was that it is NOT futile to conduct further research, so Phase 3 is already in the works!
The enrollment phase for this trial has begun, and the following universities are participating in the study:
University of Colorado at Denver
Northwestern University
Oregon Health Sciences University
University of Texas Medical Branch
University of Pittsburgh
Louisiana State University
I’m pretty excited to see the results of this trial in a few years. You can check out their website at : https://www.sparx3pd.com/
So What Now?
For now, my friend is starting his own fitness program based on the Couch to 5k Running Program (2), and he’s using his heart-rate monitor to measure his exercise intensity. Since exercise has fewer negative side effects than traditional PD medications, starting this program may help him not only delay worsening of his symptoms, but reap the benefits of exercise as well.
Whether you have PD or not, getting fit comes with benefits so strap on your heart-rate monitor and get moving!
Thanks for Reading!
(1) Schenkman, Margaret, Charity G. Moore, Wendy M. Kohrt, Deborah A. Hall, Anthony Delitto, Cynthia L. Comella, Deborah A. Josbeno, et al. “Effect of High-Intensity Treadmill Exercise on Motor Symptoms in Patients With De Novo Parkinson Disease.” JAMA Neurology 75, no. 2 (February 2018): 219–26. https://doi.org/10.1001/jamaneurol.2017.3517.
(2) “Couch to 5k - C25K Running Program.” Accessed April 24, 2021. http://www.c25k.com/.
