Concordia researchers explore how blood flow restriction training enhances low-intensity exercise benefits

In the lab of Andreas Bergdahl, associate professor in the Department of Health, Kinesiology and Applied Physiology, graduate students are exploring how external pressure on the limbs can amplify the effects of low-intensity exercise. Their findings suggest that this relatively simple technique, known as blood flow restriction (BFR) training, could help a range of populations achieve meaningful health gains — without the strain of traditional high-intensity workouts. 

In one study led by PhD candidate Daniela Presta, older adults (average age 70) completed just five weeks of online resistance training combined with BFR, with twice-weekly sessions performed at home. Despite the short duration, participants showed significant improvements in oxygen consumption during a sit-to-stand test, a key marker of functional fitness.  

Maximal oxygen consumption (VO₂ max) is a key indicator of cardiovascular health; higher values are associated with greater overall fitness and a reduced risk of cardiovascular disease. However, improving VO₂ max typically requires sustained, high-intensity training. This creates a barrier for many individuals, particularly those recovering from injury or living with conditions that limit exercise tolerance.  

“BFR can replicate many of the physiological effects of high-intensity exercise without requiring the same workload,” Bergdahl explains. “Recent studies from our lab are beginning to show just how impactful that approach can be.” 

Removing barriers to movement 

BFR training offers an alternative by creating a similar physiological stimulus at much lower intensities. 

“With BFR, we can reach that overload much more quickly while using a lower intensity,” Bergdahl says. “It stimulates the muscle to respond as though it’s working at a higher intensity than it actually is – without imposing the same degree of mechanical strain.” 

This effect is driven by a combination of metabolic and circulatory changes. By slightly occluding blood flow, the body is prompted to work harder, accelerating muscle adaptation and extending the effects that support growth. As a result, even low-load, everyday movements, such as walking, dancing or standing from a chair, can lead to meaningful gains. 

Enhancing home workouts 

Complementing Presta's work, PhD student Emma Chen is examining how BFR can be integrated into gentle, home-based programs. Her research incorporates dance-inspired movements designed to improve balance and fall prevention in older adults. In a 12-week intervention, participants follow low-intensity routines remotely, coming into the lab for periodic assessments. 

This model has proven especially valuable in contexts where participants experience limited mobility or social isolation. Combined with existing evidence on the benefits of home-based exercise for fall prevention, Chen’s findings suggest that adding BFR may further enhance outcomes without increasing physical strain. 

“BFR is not something anyone can apply casually,” Bergdahl notes. “While it can be performed at low intensity with minimal risk of injury or cardiovascular events, it remains an intervention that affects the cardiovascular system and should be carried out properly, under appropriate supervision.” 

Rethinking exercise across the lifespan 

Beyond older adults, BFR is being explored in the Bergdahl lab across a wide spectrum of populations, from individuals in rehabilitation to high-performing athletes. For those recovering from injury or experiencing limited mobility, the technique offers a way to maintain muscle mass and strength with minimal physical strain — an enduring challenge in clinical settings. 

At the same time, students in Bergdahl’s lab are investigating BFR’s potential to support people recovering from cancer or living with conditions such as Parkinson’s disease and long COVID, where fatigue can limit participation in traditional exercise. Early findings suggest BFR may help improve strength, functional capacity and, in some cases, alleviate persistent symptoms. Additional studies are also examining its role in supporting postpartum women, including work led by PhD student Arielle Rousseau.  

In parallel, the lab is extending its work into athletic performance contexts. Upcoming research will explore whether BFR can accelerate recovery from tendonitis in members of Concordia’s varsity basketball team, while other projects focus on its effects on cardiovascular response and recovery in recreational athletes.  

Collaborations with Université du Québec à Montréal and the Canadian Space Agency are also investigating how BFR could help maintain strength and function in astronauts before, during and after spaceflight. 

Rooted in decades of research 

The form of BFR used in Bergdahl’s lab uses KAATSU training, the original method developed in Japan in the 1960s by Yoshiaki Sato. First explored through self-experimentation following a leg injury, the technique was based on the simple idea that applying controlled pressure to a limb could influence muscle preservation and growth.  

Over time, this early approach evolved into a more refined system using cycles of compression and deflation, giving rise to what is now known as KAATSU, meaning “added pressure.” 

Today, KAATSU is recognized as a precise and versatile application of blood flow restriction. It can be used during exercise to enhance muscle activation and stimulate physiological responses typically associated with higher-intensity training, or after exercise to support recovery and reduce soreness.  

Toward more inclusive approaches  

While scientifically precise tools such as KAATSU belts remain central to the researchers’ work, their high cost — often reaching thousands of dollars — can limit broader adoption in community and rehabilitation settings.  

To address this barrier, Bergdahl’s lab is also testing lower-cost alternatives using elastic bands calibrated to individual comfort levels. Participants are trained to reach a target level of perceived exertion and can safely replicate the setup at home, with adjustments made over time. 

The goal is to bring these interventions into community and rehabilitation settings, making them available to the people who stand to benefit most. 

“With the right approach,” Bergdahl says, “we can make the benefits of physical activity more accessible to a broader population. That has huge implications for public health.” 
 

To learn more about this research or explore collaboration opportunities, contact Andreas Bergdahl. 

Discover the Department of Health, Kinesiology and Physiology.