Blood flow restriction augments the cross-education effect of isometric handgrip training

• Published in: European journal of applied physiology 2024-05, Vol.124 (5), p.1575-1585
• Main Authors: Wong, Vickie, Spitz, Robert W., Song, Jun Seob, Yamada, Yujiro, Kataoka, Ryo, Hammert, William B., Kang, Anna, Seffrin, Aldo, Bell, Zachary W., Loenneke, Jeremy P.
• Format: Article
• Language: English
• Subjects: Adult; Arm; Biomedical and Life Sciences; Biomedicine; Blood flow; Blood pressure; Education; Exercise; Exercise - physiology; Female; Hand Strength - physiology; Human Physiology; Humans; Isometric Contraction - physiology; Laboratories; Male; Muscle contraction; Muscle, Skeletal - blood supply; Muscle, Skeletal - physiology; Occupational Medicine/Industrial Medicine; Original Article; Physical fitness; Physiology; Regional Blood Flow - physiology; Resistance Training - methods; Sports Medicine; Strength training; Young Adult
• ISSN: 1439-6319; 1439-6327; 1439-6327
• DOI: 10.1007/s00421-023-05386-y

Introduction The application of blood flow restriction (BFR) to low-intensity exercise may be able to increase strength not only in the trained limb but also in the homologous untrained limb. Whether this effect is repeatable and how that change compares to that observed with higher intensity exercise is unknown. Purpose Examine whether low-intensity training with BFR enhances the cross-education of strength compared to exercise without BFR and maximal efforts. Methods A total of 179 participants completed the 6-week study, with 135 individuals performing isometric handgrip training over 18 sessions. Participants were randomly assigned to one of four groups: 1) low-intensity (4 × 2 min of 30% MVC; LI, n  = 47), 2) low-intensity with blood flow restriction (LI + 50% arterial occlusion pressure; LI-BFR, n  = 41), 3) maximal effort (4 × 5 s of 100% MVC; MAX, n  = 47), and 4) non-exercise control (CON, n  = 44). Results LI-BFR was the only group that observed a cross-education in strength (CON: 0.64 SD 2.9 kg, LI: 0.95 SD 3.6 kg, BFR-LI: 2.7 SD 3.3 kg, MAX: 0.80 SD 3.1 kg). In the trained hand, MAX observed the greatest change in strength (4.8 SD 3.3 kg) followed by LI-BFR (2.8 SD 4.0 kg). LI was not different from CON. Muscle thickness did not change in the untrained arm, but ulna muscle thickness was increased within the trained arm of the LI-BFR group (0.06 SD 0.11 cm). Conclusion Incorporating BFR into low-intensity isometric training led to a cross-education effect on strength that was greater than all other groups (including high-intensity training).