PURPOSE: To investigate hypertrophic signalling after a single bout of low-load resistance exercise with and without blood flow restriction (BFR). METHODS: Seven subjects performed unilateral knee extensions at 30 % of their one repetition maximum. The subjects performed five sets to failure with BFR on one leg, and then repeated the same amount of work with the other leg without BFR. Biopsies were obtained from m. vastus lateralis before and 1, 24 and 48 h after exercise. RESULTS: At 1-h post-exercise, phosphorylation of p70S6KThr389 and p38MAPKThr180/Tyr182 was elevated in the BFR leg, but not in the free-flow leg. Phospho-p70S6KThr389 was elevated three- to fourfold in both legs at 24-h post-exercise, but back to baseline at 48 h. The number of visible satellite cells (SCs) per muscle fibre was increased for all post-exercise time points and in both legs (33–53 %). The proportion of SCs with cytoplasmic extensions was elevated at 1-h post in the BFR leg and the number of SCs positive for myogenin and/or MyoD was increased at 1- and 24-h post-exercise for both legs combined. CONCLUSION: Acute low-load resistance exercise with BFR resulted in early (1 h) and late (24 h) enhancement of phospho-p70S6KThr389, an early response of p38MAPK, and an increased number of SCs per muscle fibre. Enhanced phospho-p70S6KThr389 at 24-h post-exercise and increases in SC numbers were seen also in the free-flow leg. Implications of these findings for the hypertrophic effects of fatiguing low-load resistance exercise with and without BFR are discussed.
PURPOSE: To investigate hypertrophic signalling after a single bout of low-load resistance exercise with and without blood flow restriction (BFR). METHODS: Seven subjects performed unilateral knee extensions at 30 % of their one repetition maximum. The subjects performed five sets to failure with BFR on one leg, and then repeated the same amount of work with the other leg without BFR. Biopsies were obtained from m. vastus lateralis before and 1, 24 and 48 h after exercise. RESULTS: At 1-h post-exercise, phosphorylation of p70S6KThr389 and p38MAPKThr180/Tyr182 was elevated in the BFR leg, but not in the free-flow leg. Phospho-p70S6KThr389 was elevated three- to fourfold in both legs at 24-h post-exercise, but back to baseline at 48 h. The number of visible satellite cells (SCs) per muscle fibre was increased for all post-exercise time points and in both legs (33–53 %). The proportion of SCs with cytoplasmic extensions was elevated at 1-h post in the BFR leg and the number of SCs positive for myogenin and/or MyoD was increased at 1- and 24-h post-exercise for both legs combined. CONCLUSION: Acute low-load resistance exercise with BFR resulted in early (1 h) and late (24 h) enhancement of phospho-p70S6KThr389, an early response of p38MAPK, and an increased number of SCs per muscle fibre. Enhanced phospho-p70S6KThr389 at 24-h post-exercise and increases in SC numbers were seen also in the free-flow leg. Implications of these findings for the hypertrophic effects of fatiguing low-load resistance exercise with and without BFR are discussed.
Authors: J Norrbom; E K Sällstedt; H Fischer; C J Sundberg; H Rundqvist; T Gustafsson Journal: Am J Physiol Endocrinol Metab Date: 2011-08-23 Impact factor: 4.310
Authors: Borja Guerra; M Carmen Gómez-Cabrera; Jesús Gustavo Ponce-González; Vladimir E Martinez-Bello; Amelia Guadalupe-Grau; Alfredo Santana; Vicente Sebastia; Jose Viña; José A L Calbet Journal: J Appl Physiol (1985) Date: 2011-03-24
Authors: Christopher Pignanelli; Heather L Petrick; Fatemeh Keyvani; George J F Heigenhauser; Joe Quadrilatero; Graham P Holloway; Jamie F Burr Journal: Am J Physiol Regul Integr Comp Physiol Date: 2019-12-11 Impact factor: 3.619
Authors: Lauren N Erickson; Kathryn C Hickey Lucas; Kylie A Davis; Cale A Jacobs; Katherine L Thompson; Peter A Hardy; Anders H Andersen; Christopher S Fry; Brian W Noehren Journal: Phys Ther Date: 2019-08-01
Authors: Stephen M Cornish; Eric M Bugera; Todd A Duhamel; Jason D Peeler; Judy E Anderson Journal: Eur J Appl Physiol Date: 2020-03-06 Impact factor: 3.078
Authors: David M Gundermann; Dillon K Walker; Paul T Reidy; Michael S Borack; Jared M Dickinson; Elena Volpi; Blake B Rasmussen Journal: Am J Physiol Endocrinol Metab Date: 2014-04-01 Impact factor: 4.310