BFR & Effects

There are many ways to compare the effect of Low-load resistance occlusion training (BFR) (20-50% of 1RM) vs. conventional Resistance Training (RT) / No-BFR, this results in varying conclusions of wherever BFR is more or less effective.

Source:
Slysz et al. (2016) – The efficacy of blood flow restricted exercise A systematic review & meta-analysis
Hughes et al. (2017) – Blood flow restriction training in clinical musculoskeletal rehabilitation in systematic review and meta-analysis
Grønfeldt et al. (2020) effect of blood-flow restricted vs. heavy-load strength training on muscle strength: systematic review and meta-analysis

When comparing (LL-BFR) vs (LL-No-BFR) as load matched and taken to failure, the number of repetitions needed to elicit muscular adaptions is significantly less. The most recent literature shows 10-60% fewer repetitions are needed to reach the same state of muscular fatigue. But the time-benefit of doing BFR is relative to the amount of relative pressure, being that higher pressure 70-90% of Limb Occlusion Pressure (LOP) seems to be favorable for most circumstances. This is particularly relevant when using very low-load (<25% 1RM), as there seems to be a threshold of at least 60% LOP when using very low load. From the literature, it seems that relative load and relative pressure exist on a mutually affected continuum. When using moderate-loads (40-50% of 1RM) use less pressure (40-60% LOP). On the other hand, when utilizing very low-load (<25% of 1 RM) It is strongly recommended to use higher relative pressures (70-90% LOP).

The load-pressure continuum appears important, especially in situations of early post-operation rehab with absolute load restrictions. Conversely, using BFR for the general public without any strict load restriction, it is probably favorable to utilize lower pressure (40-60% LOP) but higher relative load (30-50% 1RM).

Source:
Cerqueira et al. (2021) Repetition Failure Occurs Earlier During Low-Load Resistance Exercise With High But Not Low Blood Flow Restriction Pressures: A Systematic Review and Meta-analysis

Pignanelli et al. (2019) Low-load resistance training to task failure with and without blood flow restriction- Muscular functional and structural adaptations

Dankel et al. (2017) Are Higher Blood Flow Restriction Pressures More Beneficial When Lower Loads Are Used

Counts et al. (2016) Influence of relative blood flow restriction pressure on muscle activation and muscle adaptation

Clarkson et al. (2020) Is there rationale for the cuff pressures prescribed for blood flow restriction exercise? A systematic review

Loenekke et a. (2014) Blood flow restriction pressure recommendations: the hormesis hypothesis

Loenneke et al. (2015) Effects of exercise with and without different degrees of blood flow restriction on torque and muscle activation

Ilett et al. (2019) The Effects of Restriction Pressures on the Acute Responses to Blood Flow Restriction Exercise

Das & Paton (2022) Is There a Minimum Effective Dose for Vascular Occlusion During Blood Flow Restriction Training