This blog ended up growing on us so we’re splitting it into two parts. In the first part we’ll lay out some foundational thoughts as to what performance enhancement even means and then discuss what’s been shown in elite level performers and BFR exercise as well as provide some thought as to how we think using it makes sense. And as is usual for us to recommend, following the recent guidelines from Patterson et al is advisable.(Patterson et al. 2019)
Part 1: Performance Enhancement and Blood Flow Restriction
It seems that ever since researchers began experimenting with Blood Flow Restriction exercise (BFR) that a translation to the rehab clinic setting was inevitable. Certainly the rehab world is benefiting from the increasingly widespread adoption of this technique to restore muscle quality and quantity in load compromised individuals. And while there’s been a recent increase in clinical publications utilizing BFR, there is much left to study. On the other side of the spectrum from the injured or ill, lie individuals that routinely perform at a high level in sports or elite tactical units. The bulk of the BFR literature lies squarely in between these two populations. “Young, healthy, recreationally active individuals” are probably the most commonly written words in any exercise physiology paper, and this is certainly true of the BFR literature. Neither of those apply to the injured, ill, or elite, and thus translating what we know about BFR exercise to those populations must be done with care and acknowledgement that responses might vary or even be non-existent. At elite levels of human performance, the slightest improvement can mean the difference between winning or losing; within the tactical realm, it could mean life or death. Thus, a technique that can achieve increases in muscle size and strength with less overall tissue stress likely has some utility. A strict interpretation of “performance enhancement” involves the assessment of one's execution of a task requiring strength, speed, power, endurance, or agility, and uses an intervention either acutely or over the course of several weeks to create improvement in that task. In order to translate any findings from such a study to high level athletes or tactical athletes, these studies would need to be conducted on similar subjects. However, in application, “performance enhancement” likely covers a much broader area. This could extend to how quickly an athlete is able to return to their prior level of performance, or perhaps keeping an aging tactical athlete performing at their best despite nagging aches and pains accumulated from a life of exposure to austere environments and scenarios. Studying “performance enhancement” in this sense has unique limitations as well. In short, the evidence for BFR, or its quickly growing counterpart Ischemic Pre-Conditioning (IPC), on performance enhancement is very limited. We would not make strong recommendations for how best to use either in the achievement of performance enhancement, regardless of one’s intent with the phrase. As we always suggest on the clinical side of the house, broadening and enhancing one’s exercise physiology knowledge will greatly improve practitioners’ ability to design and reason through exercise plans with the purpose of performance enhancement as they’ll better understand specific physiologic targets for their exercise interventions and how to manipulate them to create adaptation.
BFR in the Elite Athlete
Studies seeking to measurably enhance performance in elite athletes via increased strength are sparse; there’s a total of four papers, all with rather significant methodological flaws that likely influenced the results. Perhaps two of the best papers are a study by Luebbers, and one by Yamanaka that incorporated BFR exercise into resistance training programs for collegiate level football players (NCAA D1 & D2) and saw increases in size and strength that a work matched light load control group did not.(Luebbers et al. 2014; Yamanaka et al. 2012) In both cases BFR exercises at 20% 1RM were used in addition to heavy load exercises to increase the amount of exercise volume performed. The major limitation here is that both studies used elastic wraps for BFR, all but ensuring that the restriction stimulus was not consistent across subjects.(McEwen et al. 2018) So while it’s reasonable to conclude that had they personalized pressure the results may have been even better, we learn very little from these studies about what is optimal. We only learn that it can work.
Four papers have examined using BFR to improve VO2max in highly trained persons, the most notable of which is Park et al who used BFR walking, within season, via 3 minute intervals for a total of 15 minutes work, twice a day, over two weeks to increase collegiate level basketball players VO2max by a 11.6%.(Park et al. 2010) Two studies from Ferguson’s lab were conducted in trained cyclists / triathletes utilizing 7 cycle sprint intervals of 30 seconds; BFR was used for a portion of the rest period. A 5.9% VO2max increase was noted by Mitchell and 4.5% increase in VO2max was achieved by Taylor et al.(Mitchell et al. 2018; Taylor et al. 2016) Lastly, Ursprung and Smith demonstrated that 20 minutes of walking with BFR, 5 days a week for 3 weeks improved VO2max in pararescuemen. (Ursprung and Smith 2017)
One paper has investigated using BFR exercise to enhance sprint performance and showed positive results. Abe and colleagues randomized 15 collegiate track and field sprinters and jumpers into performing squats and leg curls at 20% 1RM for 3x15 or continuing with their traditional resistance training workouts under freeflow conditions.(Abe et al. 2005) Each group continued their planned sprinting and jumping workouts. The BFR training was performed for 8 consecutive days, twice daily. The BFR group enhanced their acceleration by a tenth of a second. Below is a short form breakdown of ways in which we think BFR could be incorporated into an elite team or special forces group. These are designed to utilize the light load nature of BFR to enhance an existing training program.
- BFR resistance exercise could be used to replace some exercises as a means of reducing joint and soft-tissue loads. This “replacement” should be temporary. It likely makes the most sense within the season or immediately after the season for 6-8 weeks. It also might be done within session, comprise in entire session, or as done by Hansen et al by alternating week
- Hansen SK, Ratzer J, Nielsen JL, Suetta C, Karlsen A, Kvorning T, Frandsen U, Aagaard P. (2020). Effects of alternating blood-flow restricted training and heavy-load resistance training on myofiber morphology and mechanical muscle function.pdf. Journal of Applied Physiology. https://doi.org/10.1152/japplphysiol.00015.2020
- BFR resistance exercise could be used to add training volume w/o increasing joint and soft-tissue loads. This is basically what Leubbers and Yamanaka did above. This strategy might have utility in helping push through sticking points in training or performance.
- BFR resistance exercise could be used to "train around" existing musculoskeletal aches / pains.
- This is how Dwight Howard and many others in elite sport currently use it. Check out the story here!
- BFR exercise at a lower than usual intensity and effort level as a warm-up prior to training / performance.
- This is one way the LA Rams use BFR. They get great reports from their players on how fresh and warmed up they feel prior to practices or training sessions. You can listen to our podcast with their ATC and PT here!
- BFR endurance exercise could be used to improve fatigue resistance or get over training plateaus which are chiefly due to fatigue.
- BFR exercise with high pressure prior to competition or heavy load training to reduce pain of irritable tissues. Might have particular value in helping to manage tendinopathy.
