High-intensity exercise training in FSHD

by Amanda Hill

If you or a loved one is affected by FSHD, or any muscular dystrophy for that matter, chances are that you’ve heard it’s best not to exercise, just to avoid damaging or “using up” what healthy muscle is left. There is a pervasive uncertainty and fear among patients and doctors alike that exercise may accelerate disease progression by adding excess strain to the muscles. As far as we can tell, this attitude was spurred by a series of three studies in a mouse model of Duchenne muscular dystrophy in the early 1990s, where results were conflicting as to whether exercise was beneficial or detrimental ⁽¹⁾.

In more recent years, however, multiple well-designed and controlled clinical trials in FSHD—which has a very different disease mechanism than Duchenne—have made it the best-characterized type of muscular dystrophy with regard to the effects of exercise.

What are these studies showing thus far? In FSHD, aerobic exercise is a safe and effective way to increase oxygen uptake and endurance, and to reduce fatigue ⁽²⁾.

Recently, a group of clinicians at the University of Copenhagen, led by John Vissing, MD PhD, had the idea to take these observations a step further and evaluate high-intensity training (HIT) in people with FSHD Type 1 ⁽³⁾. HIT is a type of aerobic training carried out at an intensity level that maximizes the subject’s oxygen uptake.

Vissing and his team decided to test an HIT regimen that they adapted for individuals with FSHD to perform on a stationary bicycle. The regimen was 21 minutes long and consisted of an eight-minute warmup, followed by two sets of five-minute HIT with a three-minute break of low-intensity pedaling in between. The HIT portion of the regimen was carried out in 60-second intervals where 30 seconds was spent at low intensity, 20 seconds at moderate intensity, and 10 seconds at maximal-intensity pedaling. Individuals in the study performed this exercise regimen three times per week for eight weeks.

Notably, no episodes of muscle damage were reported, and creatine kinase levels (a marker of muscle damage) remained unchanged, indicating that the HIT regimen did not have a detrimental effect on muscle or speed up the progression of FSHD. Also notable, the FSHD individuals who performed the HIT regimen did not have an increase in fatigue, on average.

Vissing’s team also evaluated a variety of other measures of overall fitness and strength before and after the eight-week regimen. They found that HIT training increased maximal oxygen uptake and the maximal pedaling power the participants were capable of achieving, indicating that overall fitness and endurance were improved. Other standard tests used to measure FSHD progression, like the six-minute walk test and the hand dynamometer, were unchanged by the HIT regimen.

While this particular study was small, it adds to the increasing body of evidence that aerobic exercise is safe, and even beneficial, in people with FSHD. More specifically, HIT improves overall fitness without increasing fatigue or damaging muscle. And, as it turns out, HIT was preferred by the participants over other forms of training.

If you are interested in starting an HIT routine, you should speak with your doctor or a physical trainer to ensure you select a safe and appropriate regimen.

Footnotes

1. Petrof BJ. (1998). The molecular basis of activity-induced muscle injury in Duchenne muscular dystrophy. Molecular and Cellular Biochemistry. 179(1-2):111-124. PubMed.
2. Preisler N, MOrngreen MC. Exercise in muscle disorders: what is our current state? Current Opinion in Neurology. 2018;31(5):610-617. PubMed.
3. Andersen G, Heje K, Buch AE, Vissing J. High-intensity interval training in facioscapulohumeral muscular dystrophy type 1: a randomized clinical trial. Journal of Neurology. 2017;264(6):1099-1106. PubMed.