Effect of 16 weeks of resistance exercise and detraining comparing two methods of blood flow restriction in muscle strength of healthy older women: A randomized controlled trial

Objective: The objective of this study was to compare the effect of 16 weeks of resistance training using different occlusion pressures, followed by 6 weeks of detraining on the muscular strength levels of older women. Methods: This randomized-controlled trial included 56 recreationally active women (68.8 +/- 5.09 years), randomized into 5 groups: 1) Low-intensity with blood flow restriction "High" (LI + BFR_H): with higher occlusion pressure, 2) Low-intensity with blood flow restriction "Low" (LI + BFR_L): with lower occlusion pressure, 3) High-intensity (HI), 4) Low-intensity (LI), and 5) Control Group (CG). Participants completed 16 weeks of resistance exercise training, followed by a 6-week detraining period. Maximal isokinetic torque (N.m) of right and left knee extension (PTRE/PTLE) and flexion (PTRF/PTLF) was measured at pre-training, post-training and immediately following the detraining period. Results: Increased strength was observed in the LI + BFR_H, LI + BRF_L and HI groups post-training compared to baseline in the PTRE (Delta% = 27.2, 15.75 and 13.81%, p < .05, respectively), PTLE (Delta% = 25.2, 18.95 and 30.39%, p < .05, respectively), PTRF (Delta% = 36.7, 22.79 and 34.97%, p < .05, respectively) and PTLF in the groups (Delta% = 35.8, 24.93 and 26.14%, p < .05, respectively). Following the detraining period, the LI + BFR_H, LI + BFR_L and HI groups had a decrease in strength levels, but values did not decrease below baseline level. Conclusion: Low intensity BFR resistance exercise increases muscle strength in older women similar to HI, with higher occlusion pressures being more effective. Muscle strength was well preserved following a 6-week detraining period, and although reductions were observed, some preservation of strength can be explained by possible neural adaptations to exercise.