We suggest that higher relative pressures may not be necessary when exercising under BFR.

Increases in 1RM strength from resistance training are related to the specificity of exercise and are likely driven by mechanisms other than muscle growth. Muscle Nerve 56: 307-314, 2017.

No abstract

The purpose of this study was to determine whether arm circumference is predictive of arterial occlusion in the standing position and to determine the change in pressure before and immediately after exercise. Thirty-one participants had their arm circumference, blood pressure and standing arterial occlusion determined before exercise. Participants then completed elbow flexions at 40% of resting arterial occlusion at 30% of their one repetition maximum (1RM). The goal repetitions for the exercise included one set of 30 repetitions followed by 3 sets of 15, with 30s rest between sets. Immediately following the last set, postexercise arterial occlusion was determined. Two different models of hierarchical linear regression were used to determine the greatest predictor of standing arterial occlusion. Our final model explained 69% of the variance in arterial occlusion with arm circumference (β = 0·639, part = 0·568) explaining more than brachial systolic blood pressure (β = 0·312, part = 0·277). Standing arterial occlusion increased from pre- [138 (15) mmHg] to post- [169 (20) mmHg] exercise (P<0·001). In conclusion, the cardiovascular response to blood flow restriction (BFR) in the upper arm following 4 sets of elbow flexion exercise decreases the relative arterial occlusion pressure. In addition, we confirm previous data that circumference explains the most unique variance in arterial occlusion pressure in the upper body. These findings are important as they provide additional insight into making the pressure more uniform between participants throughout exercise.

Predation of the barnacles Balanus balanoides and Elminius modestus by the common dog-whelk, Nucella lapillus was studied in the laboratory. Greater numbers of B. balanoides were taken as prey unless the whelks had been previously subjected to an extensive period of starvation.Selective predation is discussed in the light of similar studies on Nucella and related predatory species. The effects of prey selection on the competitive interactions of the prey species are also considered.The method of predatory attack involves either a drilling or a prizing technique. The latter is used predominantly when Nucella attacks E. modestus, whereas drilling is employed to a far greater extent when attacking B. balanoides. Attacks using the drilling technique are usually made at the occludent margins of the opercular valves. I N T R O D U C T I O NThe biology and predatory activity of Nucella lapillus (L.) was studied by Moore (1938) and more recently by Largen (1967a, b), who concluded that adults take a variety of prey species and may resort to cannibalism. Moore (1938) comments that adult Nucella seemed to prefer barnacles as a food source, and had a considerable effect on their population. Wood (1968) found that the related prosobranch Urosalpinx cinerea preferred barnacles to mussels or oysters. In a somewhat abnormal environment, Morgan (1972) discovered Nucella with an acquired preference for Cardium edule.As well as evidence of prey species selection there are records of prey size selection. Menge (1973) demonstrated that the related species Thais armiger selects the largest individuals of its prey, the limpet Siphonaria normalis. Largen (1967 a) showed adult Nucella to prefer a certain size range of mussels. Connell (1961 a) presents evidence of a preference for larger individuals of Balanus balanoides. He suggested (Connell, 19616) that this size preference resulted in a prey species preference such that Nucella took greater numbers of B. balanoides than the smaller competitor Chthamalus stellatus and in a corresponding situation on the east coast of North America he reported that Thais emarginata predatory on a mixed population of B. glandula and C. fissus fed on the larger species (B. glandula) in preference to the smaller C. fissus. Later work by Connell (1970) with other species of Nucella showed that they took larger specimens of Balanus