One-minute, short bursts of high-intensity interval training for 19 minutes may be more effective for improving fitness among people six months or more after a stroke than traditional, 20-30 minutes of moderate-intensity exercise sessions, according to research published today in Stroke, the peer-reviewed scientific journal of the American Stroke Association, a division of the American Heart Association.
"This study shows that people with stroke can also benefit from high-intensity interval training," said Kevin Moncion, Ph.D., a physiotherapist who led this study as part of his doctoral studies at McMaster University in Hamilton, Ontario, Canada. "With the right support and guidance, stroke survivors can safely and effectively engage in high-intensity interval training, significantly improving their overall health and recovery."
The multi-site trial took place between September 2018 and March 2024 and included stroke survivors between six months to 5 years after a stroke. Researchers randomly grouped participants to receive either three days per week of 12 weeks of high-intensity interval training or three days per week of 12 weeks of traditional moderate exercise sessions. The high-intensity interval training protocol involved ten 1-minute intervals of high-intensity exercise, interspersed with nine 1-minute low-intensity intervals, for 19 minutes total. The moderate intensity continuous training involved 20 to 30 minutes of steady exercise at moderate intensity.
Researchers then compared fitness levels, cardiovascular risk factors such as blood pressure and stiffness of blood vessels, walking speeds and distances between the two groups. All assessments were repeated one final time 8 weeks after the exercise interventions to evaluate whether the changes were sustained over time.
Researchers found:
- The high-intensity interval training group's cardiorespiratory fitness levels (rate of oxygen consumed at peak exercise) improved twice as much as the moderate intensity continuous training group: 3.5 milliliters of oxygen consumed in one minute, per kilogram of body weight (mL/kg/min) compared to 1.7 mL/kg/min.
- The improvement in the high intensity interval training group stayed above clinically important thresholds even at the 8-week follow-up (1.71 mL/kg/min), whereas the moderate intensity continuous training group did not (0.67 mL/kg/min).
- Both the high intensity interval training and moderate intensity continuous training groups gained improvement in walking endurance, as measured by distance walked over 6 minutes. At baseline both groups could walk about 355 meters (the approximate distance of three American football fields) over 6 minutes. After 12 weeks of exercise both groups increased their walking distance by 8 meters and after the 8-week follow-up they increased their walking distance by 18 meters.
"This is the first randomized trial to examine a time-efficient, high intensity interval training program to incorporate a phased and progressive approach," said senior author Ada Tang, Ph.D., a physiotherapist, professor and assistant dean of Rehabilitation Science at McMaster University. "We also used an adaptive recumbent stepper, which we believe allowed more people to participate in high-intensity interval training, even those who cannot walk fast enough or long enough on a treadmill."
The limitations of the study include that study participants were higher functioning stroke survivors from a physical standpoint who were at lower risk for heart disease. Study minimum criteria included the ability to walk 10 meters without physical assistance of another person, although the use of cane or walker was permitted. Outcome assessments were unblinded at follow-up, which may have influenced results. Lastly, enrollment and exercise for the trial was halted two years for COVID-19 lockdowns, thus inflating the rate of participants who left the study and potentially limiting the statistical power of the analysis.
In 2021, there were 7.44 million deaths attributable to stroke worldwide, according to the American Heart Association's Heart Disease and Stroke Statistics 2024 Update.
Future research should examine stroke survivors with more severe impairment in physical function or heart disease risk, according to the study authors.
"Stroke rehabilitation professionals now have evidence to support implementing short, high-intensity interval training protocols in clinical practice. We showed our program is safe and effective at improving fitness and walking distance in people after stroke, which are important outcomes for stroke survivors," Tang said.
Study details and background:
- The study conducted at McGill University in Montreal and McMaster University in Hamilton, Canada included 82 predominantly white adults, (50 men, 32 women), ages 40 to 80. All had mild or minimal disability from a stroke about 1.8 years earlier.
- Participants exercised on adaptive recumbent steppers that allow for stroke survivors with a wide range of abilities to exercise at high intensities.
- Assessments were done 3 times in total: before starting exercise training (baseline, 0 weeks), immediately after exercise (post, 12 weeks), follow up 8 weeks after the intervention ended (i.e. 20 weeks from baseline).
- At each assessment, researchers measured cardiovascular health fitness levels, including resting blood pressure, stiffness of arteries, waist-hip ratio (calculated by waist circumference at the belly button and hip circumference at the hip bone), and mobility (walking speed and distance).
- No participants experienced any adverse effects, including feeling tired, shortness of breath, muscle soreness, cramps or lightheadedness during exercise.
FAQs
The research, published in Stroke on Aug. 8, 2024, found that one-minute bursts of high-intensity interval training over 19 minutes was more effective than traditional moderate exercise for improving the body's aerobic fitness after a stroke.
Is intense exercise better than moderate exercise? ›
Your exercise intensity must generally be at a moderate or vigorous level for the most benefit. For weight loss, the more intense or longer your activity, the more calories you burn. Exercise progression is important, but this should be at a gradual rate.
What are short bursts of high intensity exercise? ›
Short bursts increase endurance and strength as your effort pushes heart, lung and muscle capabilities beyond normal levels. And, along with the extra calories burned during the burst, an increased metabolic rate continues to burn extra calories afterward. An endorphin rush will also boost mood.
What is alternating short bursts of intense activity with longer intervals of less intense activity? ›
Traditionally, HIIT features 30 to 90 seconds of high-intensity effort followed by an equal or longer period of lower-intensity activity or rest. High-intensity is often defined as reaching 85% of your maximum heart rate (see "All about your heart rate" in the June 2023 Heart Letter).
What are the effects of high intensity interval training after stroke? ›
JAMA study finds that high-intensity interval training improves stroke patients' mobility more than moderate aerobic exercise. KU researcher Sandra Billinger, Ph. D., was part of a multi-site study that may change how stroke rehabilitation is conducted.
Is it better to do short intense workouts? ›
Studies have found that short bursts of intense exercise (aka HIIT) provide greater benefits than longer, less intense workout sessions (and HIIT may be more enjoyable too). Translation: You'll need to sweat at least a little if you want to make the most of your time.
Is vigorous exercise better than moderate activity Why? ›
Many studies show that moderate-intensity activity can result in a wide variety of health benefits, such as weight loss, reduced blood pressure, and even improved mental health. Vigorous intensities are beneficial for improved fitness and continuing progress but are not a mandatory level that everyone needs achieve.
Can doing short bursts of high-intensity exercise be most effective to weight loss than moderate workouts? ›
High intensity interval training is a very efficient way to exercise and may help you burn more calories than you would with other forms of exercise. Some of the calories burned as a result of high intensity intervals come from a higher metabolism, which lasts for hours after exercise.
Do short bursts of exercise help? ›
The researchers found that these short bursts of physical activity throughout the day, lasting less than 10 minutes total, were linked to a 52% decrease in the risk of premature death, as well as a 41% decrease in the risks of heart attack and stroke, compared to getting no physical activity.
What type of exercise is intense has short bursts of activity working your muscles so hard they produce energy without oxygen? ›
Anaerobic exercise involves short, fast, high-intensity exercises that don't make your body use oxygen like it does for cardio (or aerobic) activities. Instead, anaerobic activities break down glucose that's already in your muscles for a form of energy.
But how people did their vigorous activity also stood out. The findings showed that accumulating several short bouts (about two minutes each) of vigorous activity at different times throughout the day might be especially beneficial.
What is exercise done in short fast bursts called? ›
When exercising for less than 30 minutes, it is best to do what is called HIIT, or high intensity interval training, which is short all-out effort bursts followed by more moderate efforts of exercise. HIIT burns a lot of calories in a short amount of time, helping you lose fat and gain muscle.
What intense physical activity requires short bursts of energy? ›
Exercises and movements that require short bursts of intense energy are examples of anaerobic exercises. These include: weightlifting. jumping or jumping rope.
What happens to stroke volume as exercise intensity increases? ›
Current research supports a continual increase in stroke volume during exercise of increasing intensity in some trained and untrained subjects.
What is high intensity therapy for stroke patients? ›
This strategy, called high-intensity interval training (HIT), uses bursts of concentrated effort alternated with recovery periods to maximize exercise intensity. Three poststroke HIT studies have shown preliminary effectiveness for improving functional recovery.
Why is high intensity interval training effective? ›
HIIT and other high-intensity exercise programs help you burn a lot of calories in a short amount of time. Research has also showed that you keep burning calories for hours after your workout is finished. These workouts typically cause you to burn more fat and build muscle.
Are high-intensity workouts better? ›
Meyer added, “HIIT has been shown to provide better results in cardiorespiratory fitness, and could be thought of as more efficient.” Chokshi and Chris Kusmiesz, MS, an exercise physiologist with the Penn Sports Cardiology and Fitness Program, agreed.
Is it okay to do intense exercise everyday? ›
“Vigorous cardio every day can sometimes be too much. If you have heart or joint problems, for example, doing intense daily cardio workouts may not be safe or good for your body.” Doing the same cardio workout five to seven days a week may be fine if you: Don't have injuries.
Does intense exercise burn more fat? ›
The more you move, and the more intense the movement is, the more calories you burn. Weight training can lead to an increase in muscle mass and a decrease in fat mass. If your muscle and fat change by the same amount, the numbers on the scale may stay the same, but your body may look and feel different.
Is high-intensity exercise better than moderate intensity exercise for weight loss? ›
Doctor's response. At lower intensities of exercise, muscles burn a higher percentage of fat than carbohydrate, but not necessarily more total fat, or more total calories, than at higher intensities.
