Strength training with and without arteriovenous blood flow restriction improves performance, regardless of changes in muscle hypertrophy, in Wistar rats

Abstract

Strength training (ST) with blood fl ow restriction (BFR) is known to promote increases in hypertrophy and strength sometimes similar to traditional ST despite the effects of the arterial BFR on muscle adaptations and safety are not well established.The aim of this study was to assess whether ST with arterial BFR is able to improve muscular adaptations, performance and its safety in Wistar rats. Animals aging 8 weeks were divided in four groups: sedentary sham (S/S), sedentary with arterial BFR (S/BFR), trained sham (T/S), and trained with arterial BFR (T/BFR). Training protocol consisted of four weeks of ST composed by six sets of 10 ladder climbing with 50% of 1 maximal voluntary contraction. Body weight, epididymal fat, maximum loaded weight, manual grip strength, muscular hypertrophy index, systolic blood pressure, enzyme activity of superoxide dismutase, nitrite/nitrate concentration and tumor necrosis factor alpha were analyzed. The BFR rate was between 36% and 38%. T/BRF was effective to promote strength and hypertrophy. T/S is an alternative to improve strength, but it did not promote hypertrophy. Furthermore, we found no signifi cant cardiac and metabolic changes. Thus, T/BFR is able to improve muscle adaptations and performance in rats, without causing cardiovascular and metabolic damage.

Effect of Using Different Intensities in Resistance Training for Muscle Hypertrophy Gains—A Narrative Review

“…Recently, strategies to optimize gains in strength, hypertrophy, and local muscular endurance have been adopted to compare the effect of lower intensities (e.g., 20% of 1RM for gain in local muscular endurance) (38) and the fractionation of the series (rest pause and cluster sets for gains in hypertrophy and maximum strength) (44) to enhance muscle adaptations to RT. In this same line, strength training with blood flow restriction has gained prominence (9,13,20,23). However, despite the existing evidence on the subject, the present work does not intend to achieve this approach, limiting itself only to analyzing evidence of different intensities and volumes of physical training.…”