|No, the study did not use a simple rope or band to restrict blood flow. Instead an automated system was used that kept the pressure at stable 100mmHg.|
The aim of the bachelor students' study was to investigate how a periodized combination of classic resistance and blood flow restricted resistance exercise (BFRE) compares to regular training when it comes to increase in quadriceps muscle growth and strength.
Now as great as this sounds, the study has several important weaknesses (few, though, considering the fact that this is undergrad research) due to which it should be considered a "proof of concept", not a "classic + BFR is better than classic alone" study:
- untrained subjects - 10 males and 10 female (4 dropouts), to be specific,
- no dietary standardization (only a 21g vegetable protein shake after workouts),
- unilateral (=one leg only) resistance training for the legs, only, and
- the lack of a non-BFR periodized control group
|BRF After Each Set? More!|
During the BFR weeks, subjects exercised every day, but switched back and forth between leg extensions and presses with the former being done on Monday, Wednesday and Friday, and the latter being performed only on Tuesday and Thursday. Both exercises were performed wearing an automated cuff that was set to regulate the pressure at 100mmHg during the workouts. The BFR workouts, itself, consisted of four sets of unilaterally leg press or leg extension the subjects did at a set pace of 60 BPM and 50 BPM for the extensions and press, respectively. As usual, the intensity was reduced for the BFR weeks: 20 % of 1RM in leg extension and 30 % of 1RM in the leg press. With the short rest of thirty seconds after the first set of 30 reps, the 2nd set of 10 reps and the third and fourth set, during which the subjects performed to concentric failure, the BFR workouts were yet still pretty intense.
|Figure 1: Size (left) and strength (right) gains over the 10-week study period / no sign. sex-differences (Cortobius. 2016).|
- Cortobius, Daniel, and Niklas Westblad. "Optimizing strength training for hypertrophy: A periodization of classic resistance training and blood-flow restriction training." (2016).
- Wernbom, Mathias, Jesper Augustsson, and Roland Thomeé. "The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans." Sports medicine 37.3 (2007): 225-264.