This article summarises some of the latest findings regarding blood flow restriction training (BFRT).

As newer evidence emerges, the article will be updated with relevant information;

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Introduction to BFRT

Blood flow restriction training (BFRT) involves using a strap or pneumatic cuff proximally to the muscle that is being trained (closer to the trunk of the body). This is used to partially restrict arterial blood inflow while occluding/blocking venous outflow during a bout of exercise. It is often used in combination with lower training loads (20%–30% of 1-RM; 15–30 repetitions per set).

1. Positive Strength Benefits for Older Adults

Three meta-analyses found that BFRT had positive effects on muscular strength and hypertrophy in older individuals aged 50 and above:

• Rodrigo-Mallorca et al. (2021)

• Baker et al. (2020)

• Centner et al. (2018)

By incorporating BFR into low-load RT or walking, the effects on muscle mass and strength were augmented. Low-load BFRT may thus be an effective exercise alternative for older populations with contraindications regarding high training loads.

In comparison with high-load resistance training (RT), low-load BFRT produced comparable changes in muscle mass, but lower increases in muscular strength.

However, a key limitation of the systematic reviews and meta-analyses done on BFRT in older adults is the lack of high-quality evidence. Caution should be exercised given the moderate to high uncertainty of the current available research.

2. No Detrimental Effects on Other Systems

BFRT produced favourable or non-detrimental effects on the cardiovascular, endocrine, and musculoskeletal systems. A systematic review also found mixed effects on psychosocial outcomes when using BFRT.

Similar to other papers, there were no known adverse effects when dosed properly.

3. Safe for Knee-Related Musculoskeletal Disorders

From the available evidence, a systematic review found that BFRT appears to be a safe strengthening approach for knee-related musculoskeletal disorders. In the randomized controlled trials, individuals exposed to BFRT did not experience any greater risk of adverse events than individuals exposed to exercise alone. When delivered according to clinical recommendations, BFRT has no greater risk than other RT approaches.

4. Beneficial for Athletic Performance

A systematic review observed that BFRT has the potential to increase strength and markers of sports performance (sprint time, agility tests, and jump measurements) in healthy athletes.

That said, there was variability in terms of whether BFRT can lead to increased muscle size.

Combining traditional high-load resistance training with low-load BFRT may allow athletes to maximize athletic performance, and more studies need to be conducted to find an optimal occlusive pressure to maximize training improvements.

5. Useful for Power Development

A meta-analysis concluded that BFRT was more effective in improving the explosive power of lower limbs compared to traditional RT in healthy people.

In addition, the same study found that using a wide cuff (≥ 10 cm) during training improved explosive power better than with a narrow cuff. This is in line with clinical recommendations which encourage wider cuffs for patient safety.

6. Mixed Findings on ACL Rehabilitation

A meta-analysis showed that BFRT in the post-operative period helps to significantly reduce quadriceps muscle atrophy compared to a control group. However, no significant differences were observed for patient-reported outcome measures.

Another systematic review found that the available evidence was inconsistent, with no indication of consistent clinically meaningful differences between BFRT and conventional therapy.

A second systematic review concluded that BFRT may benefit muscular strength and hypertrophy similar to high-intensity RT, as well as reduce pain intensities.

More high-quality research is thus required for a better comparison between BFRT and conventional therapy for ACL rehabilitation. Nonetheless, the available evidence suggests that BFRT is generally safe and may have some benefits, although these benefits may not be clinically significant.

Pre-operative BFRT failed to show any significant clinical benefits. However, this is likely due to insufficient evidence, as well as a preconditioning period that was lacking in both duration and frequency.