Low-intensity resistance exercise associated with partial blood-flow restriction (BFR; 30% of onerepetition
maximum [1RM]) has been proposed as an effective alternative to high-intensity
resistance exercise (HI-RE; 80% of 1RM) to increase muscle mass. Interestingly, muscle
adaptations related to BFR seem to be independent of the occlusion pressure magnitude, suggesting
that muscle mass accrual can be achieved even with low loads. However, the occlusion pressure
magnitude is thought to alter the psychophysiological stress related to BFR as measure by rating of
perceived exertion scales (RPE). Despite of that, the effects of different occlusion pressures on the
RPE response warrants further investigation. Additionally, session RPE (RPE-S) and pain levels
can help gain insights as to whether manipulations in occlusion pressure can alter the stress related
to BFR. The present study aimed to compared the RPE, RPE-S and pain levels across different
magnitudes of occlusion pressures. Furthermore, all BFRs protocols were compared with a HI-RE.
Twelve male subjects (age: 24.5 ± 1.5 years, height: 1.78 ± 0.04 m, body mass: 83.4 ± 11.2 kg) not
engaged in lower limbs RE for the last six months participated in the present study. Subjects
performed all RE protocols in a randomized and cross-over way with 72 hours apart: 1) RE with
40% of total occlusion restriction (BFR40); 2) RE with 50% of total occlusion restriction (BFR50);
3) RE with 60% of total occlusion restriction (BFR60); 4) RE with 70% of total occlusion
restriction (BFR70); 5) RE with 80% of total occlusion restriction (BFR80) and; 6) RE without
occlusion pressure restriction (HI-RE). BFR protocols and HI-RE were performed with 30% and
80% of 1RM, respectively. RPE and pain levels were measured before exercise and immediately
after each set. RPE-S was measure 30 minutes after the end of exercise session. The main results
showed that lower-pressure BFR protocols (i.e., BFR40 and BFR50) presented overall lower RPE
response as compared with higher-pressure BFR (i.e., BFR70 and BFR80) and HI-RE protocols. In
respect of RPE-S, BFR60, BFR70 and BFR80 protocols showed higher values than BFR40 and
BFR50 protocols. The BFR80 protocol showed greater RPE-S when compared to all others
conditions. Regarding pain levels, BFR40, BFR50 and HI-RE protocols, showed lower values than
BFR60, BFR70 and BFR80 protocols. In conclusion, higher BFR protocols (BFR70 and BFR80)
promote higher RPE, sRPE and pain compared with lower BFR protocols.