Impaired proprioception can provide faulty sensory feedback to the brain during movement, resulting in an increased risk of injury. Although several safety concerns about blood flow restricted exercise have been investigated, no research has observed how this exercise affects proprioception. Objectives: To investigate the effects of walking with and without practical blood flow restriction (pBFR) on muscle fatigue and knee proprioception. Design: Within-subject Randomized Crossover Design Methods: Fourteen healthy young adults (9 males and 5 females) walked on a treadmill at 5.6 km/h with a fixed grade for fifteen minutes either with or without elastic belts (using the moderate perceived tightness, “7 out of 10”). Absolute angular error of a standing position sense test (index of proprioception) and peak/average power outputs of countermovement jumps (index of fatigue) were measured before and immediately after exercise. Results: For absolute angular error, there was no evidence of a difference (BF10 = 0.64) between walking with and without pBFR [pBFR: Δ ‒ 1.5 ± 3.8 ˚ vs. Control: Δ 0.19 ± 3.8 ˚]. The change in peak power was not different (BF10 = 0.28) between conditions [pBFR: Δ ‒ 34.5 ± 1019 W vs. Control: Δ 150 ± 1616 W]. Similarly, the change in average power was also not different (BF10 = 0.28) between conditions [pBFR: Δ 9.1 ± 53 vs. Control: Δ ‒ 3.4 ± 73 W]. Conclusions: There was no evidence that walking with pBFR induced fatigue or impairment of knee proprioception, suggesting that walking with pBFR might be safely performed without increasing the risk of injury.
Resistance training (RT) volume is considered a critical variable to induce neuromuscular adaptations (i.e., increased muscular strength). However, emerging findings have allowed us to revisit the role of volume in strength gains. Objectives: In the present study, we seek to present these emerging findings to discuss the role of RT volume in one-repetition maximum (1RM), isometric, and isokinetic strength gains. In addition, we propose alternative ways to test whether or not volume plays a determining role in strength adaptation. Design & methods: We reviewed the literature on RT volume and strength. In addition, we examined the RT literature to provide alternative ways to investigate the effect of volume on changes in strength. Results/conclusions: From the recent findings, we argue that an increase in strength can be achieved through a refined interaction between skill enhancement, regular use of high loads, and neuromuscular fatigue management; these points can be obtained from different RT volumes. From an inquiring point of view, we suggest that future investigations that aim to verify the effects of volume on muscular strength may consider the inclusion of high load sessions (80-100% of 1RM), periodically (e.g., every three or four weeks), in both low and high-volume groups, as well as considering the inclusion of different strength measures (e.g., isokinetic and isometric). We believe that this will help to clarify the nature of the relationship between RT volume and strength adaptations.