Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength

The aim of this study was to determine whether increases in post-exercise endocrine response to low-load resistance exercise with blood flow restriction and high-load resistance exercise would have association with increases in muscle size and strength after an 8-week training period. Twenty-nine untrained men were randomly allocated into three groups: low-load resistance exercise with (LL-BFR) or without blood flow restriction (LL), and high-load resistance exercise (HL). Participants from LL-BFR and LL groups performed leg extension exercise at 20% of one repetition maximum (1RM), four sets of 15 repetitions and the HL group performed four sets of eight repetitions at 80% 1RM. Before the first training session, growth hormone (GH), insulin-like growth factor 1 (IGF-1), testosterone, cortisol, and lactate concentration were measured at rest and 15 min after the exercise. Quadriceps CSA and 1RM knee extension were assessed at baseline and after an 8-week training period. GH increased 15 min after exercise in the LLBFR (p = 0.032) and HL (p < 0.001) groups, with GH concentration in the HL group being higher than in the LL group (p = 0.010). There was a time effect for a decrease in testosterone (p = 0.042) and an increase in cortisol (p = 0.005), while IGF-1 remained unchanged (p = 0.346). Both muscle size and strength were increased after training in LL-BFR and HL groups, however, these changes were not associated with the acute post-exercise hormone levels (p > 0.05). Our data suggest that other mechanisms than the acute post-exercise increase in systemic hormones induced by LL-BFR and HL produce changes in muscle size and strength.

Laurentino, G. C., Loenneke, J. P., Ugrinowitsch, C., Aoki, M. S., Soares, A. G., Roschel, H., Tricoli, V. (2022). Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength. Journal of Human Kinetics, 83, 235-243. https://doi.org/10.2478/hukin-2022-0095

Laurentino, G. C., Loenneke, J. P., Ugrinowitsch, C., Aoki, M. S., Soares, A. G., Roschel, H., and Tricoli, V. (2022). Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength. Journal of Human Kinetics, 83, pp.235-243. https://doi.org/10.2478/hukin-2022-0095

Laurentino, Gilberto et al. “Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength.” Journal of Human Kinetics, vol. 83, 2022, pp. 235-243. doi:10.2478/hukin-2022-0095.

Laurentino GC, Loenneke JP, Ugrinowitsch C, Aoki MS, Soares AG, Roschel H et al. Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength. Journal of Human Kinetics. 2022;83:235-243. https://doi.org/10.2478/hukin-2022-0095