BFR Compared To Other Exercise Modalities
Grønfeldt et al. (2020) Effect of blood-flow restricted vs. heavy-load strength training on muscle strength- Systematic review and meta-analysis
Centner et al. (2018) Effects of Blood Flow Restriction Training on Muscular Strength and Hypertrophy in Older Individuals: A Systematic Review and Meta-Analysis
Effect Size – A Nuanced Perspective
There are many ways to compare the effect of occlusion training (BFR) vs. Conventional Resistance Training (CRT) and this results in varying conclusions of wherever BFR is more or less effective
Short-term muscle mass – Probably BFR
Long-term muscle mass – Approximately same
Short-term muscle strength – Approximately same
Long-term muscle strength – Probably CRT
Muscle endurance – BFR
Rate of Force Development (RFD) e.g. running velocity and vertical jump – CRT
Slysz et al. (2016) – The efficacy of blood flow restricted exercise A systematic review & meta-analysis
Load Restricted – Comparison (injury or impaired):
Short-term muscle mass – (BFR Long-term muscle mass – (BFR)
Short-term muscle strength – (BFR)
Long-term muscle strength – (BFR)
Muscle endurance – (BFR)
Rate of Force Development (RFD) – (Often not possible in early rehab stages)
Hughes et al. (2017) – Blood flow restriction training in clinical musculoskeletal rehabilitation in systematic review and meta-analysis
Occlusion Training aka. Blood Flow Restriction (BFR) Training – is Partial Restriction of Blood Flow Not Actual Occlusion
The concept is known under several different terms but originates from 1970s Japan, where it is called Kaatsu training. It is primarily an alternative or supplement to conventional resistance training and musculoskeletal rehabilitation.
Traditionally the recommendation for resistance training is to use a load that is at least 60%, of what you can lift once (60% of 1RM). However, as shown above, various research articles and Meta-analysis proves that low load exercise augmented by BFR is about as beneficial as conventional resistance training and aerobic exercise!
In summary there are evidence for occlusion training has advantages and less disadvantages!
Nerd Alert – The Adaptive Muscle Response
The partial restriction of blood flow in combination with muscles contractions creates a short-term edema (cell swelling) around the muscle cells which limits the supply of oxygen and nutrients so that metabolites accumulates (Cayot et al., 2014). This initiates a cascade of physiologic process, like the increase of growth hormone secretion, as approximately 2-3 fold greater compared to conventional resistance training. But also the increased activation of muscle satellite cells, about two fold larger than than conventional resistance training. This upregulates the net protein synthesis.(Yasuda et al., 2014; Segal et al., 2010; Roos and Lohmander 2003). Check also the Blog post from September 17, 2020.
↑ Muscle oxygenation – hypoxia leading to short term ischemia
↑ Metabolite accumulation – accumulation of waste products
↑ Recruiting fast twice muscle fibers
↑ Cell Swelling
↑ Growth hormone 200-300% compared to conventional resistance training – relevant for bone and tendon health
↑ Satellite cell proliferation
↓ Secretion of muscle growth inhibitors (myostatin) – especially important for building muscle tissue
↑ Netto protein synthesis = Hypertrophy (muscle growth)
↑ Muscle strength and endurance
↓ Metabolic resistance – relevant for metabolic syndrome and diabetes
↑ Anaerobic threshold
↑ Mitochondrial content
These processes are further described in the scientific literature, especially by the leading researcher in the field of Associate Professor Jeremy P. Loenneke as he is attributed to a large part of the accumulated knowledge. For the past 10 years, he has published scientific articles on the underlying mechanisms and effects of occlusion training or Blood Flow Restriction. Overall there are published more than 300 scientific studies across all continents, which demonstrates the effect of occlusion training.
Other Relevant Effects Associated With BFR Training
- Treatment of sarcopenia by increasing muscle mass (protective for a wide range of age-related issues and chronic conditions (How When & Why BFR)
- Greater muscle strength – directly transferable to everyday activities (ADL) Fall prevention
- Improved circuit function
- Better self-reported health
BFR can be relevant for the top athlete to the seniors!