High-intensity interval training improves stroke survivors’ mobility more than moderate aerobic exercise, a new clinical trial has found.
Stroke patients who walked short intervals at a rigorous pace, followed by short intervals, had better mobility after three months than those who walked at a moderate pace throughout the session.
The findings of the study could help to change how stroke rehabilitation is delivered, the research team said.
“It’s very difficult when you’ve had a life-changing stroke and all of a sudden, you can’t do the things that you did before,” Dr Sandra Billinger, part of the research team, said.
“Intervening early is an important part of recovery, but people who have been living with limited mobility are also very excited to improve, and we wanted to find the best way for them to do so.
“I think it’s important for the stroke rehabilitation and recovery community to realise that we can implement a feasible high intensity interval training protocol that results in improved walking in people living with chronic stroke.”
The clinical trial was the joint project of the University of Cincinnati in Ohio, the University of Delaware-Newark and KU Medical Center and enrolled 55 participants who were still experiencing walking problems six months to five years after their stroke.
Of the 55 enrolled study participants who were still experiencing walking problems six months to five years after their stroke, KU Medical Center studied 18 of them.
In all study locations, researchers randomly divided the number of participants into two groups. The first group practiced what researchers call moderate aerobic training (MAT), a standard method of rehabilitation. The second group practiced a new method called high-intensity interval training (HIIT).
In the first group, participants in safety harnesses walked on a treadmill at a moderate pace for 45 minutes three times a week for three months. Their progress was measured by how well they walked, both on and off the treadmill, at the end of the study.
In the second group, participants also walked on a treadmill wearing a safety harness. But instead of a steady pace, these participants walked vigorously for 30 seconds, then rested for 30 to 60 seconds before repeating the process.
They, too, spent 45 minutes doing the therapy three times a week for three months, and their progress was measured by how well they walked at the end of the study.
At the one-month point of the study, the two groups had similar results. But after two months and again at three months, the high-intensity group did significantly better than the moderate-intensity group.
At the end of three months, the MAT group improved 90 per cent over their pre-study mobility. The HIT group improved 184 per cent over baseline.
“So, intensity does matter,” Dr Billinger, professor of neurology and vice chair of stroke translation research at the University of Kansas School of Medicine, said.
“What’s important to recognise is that both groups improved. It’s just that the HIIT group improved more over that 12-week period.”
Previous stroke studies conducted with high-intensity interval training had shown little difference between MAT and HIIT, but those studies concluded after eight weeks, according to Dr Billinger.
The idea to lengthen the trial’s timeline was a key variable that led to this study’s groundbreaking results.
“We wanted to identify the optimal duration that improved walking, and our data show three months of training is best,” she said.
The study team is “truly excited” about this research potentially being implemented into outpatient physical therapy.
Dr Billinger pointed out that most physical therapy settings already have the treadmills and equipment needed to follow high-intensity interval training.
“So, if we can give them the guidance on the intensity and the protocols of what we do, we hope that this will be part of physical therapy’s clinical practice guidelines,” she added.
