Acute Hormonal Responses to Multi-Joint Resistance Exercises with Blood Flow Restriction

Abstract

The purpose of this study was to investigate the acute effects of multi-joint resistance exercises (MJRE) with blood flow restriction on hormonal responses. Ten men participated in the study and underwent two experimental protocols in random order: four sets (30, 15, 15, and 15 reps, respectively) of MJRE (half squat and horizontal chest press) were performed with 20% of 1RM and a rest time between sets of 30 s, combined with intermittent blood flow restriction (LI + BFR protocol); and four sets (8, 8, 8, 20 reps, respectively) of the same MJRE performed with 75% of 1RM load (HI protocol), with a 90 s rest between the first three sets and 30 s between the third to the fourth set. Blood samples were collected before (PRE), immediately after (POST), and 15 min after the performance of MJRE (POST15). A time effect was observed for growth hormone (GH) and insulin-like-growth-factor-1-binding-protein-3 (IGFPB-3), but no protocol effects or interactions between protocol and times were observed (p > 0.05). There was no effect of either protocol or time (p > 0.05) on total testosterone, free testosterone, or cortisol concentrations. However, significant (p < 0.05) increases were observed in the GH serum concentrations of 2072.73% and 2278.5%, HI, and LI + BFR protocols, respectively, from the PRE to POST15 test. In addition, there was an increase of 15.30% and 13.29% in the IGFPB-3 concentrations (p < 0.05) from PRE to POST0 times for HI and LI + BFR protocols, respectively. Furthermore, there was a decrease of −6.17% and −11.54%, p = 0.00, between the times POST0 to POST15 in the IGFPB-3 for the HI and LI + BFR protocols, respectively. It is concluded that multi-joint resistance exercises combined with intermittent blood flow restriction seemed to promote acute hormonal responses in a manner similar to traditional exercise with high loads. Future studies may investigate whether chronic use of LI + BFR with MJRE may promote muscle hypertrophy.

Hormonal, immune, and oxidative stress responses to blood flow‐restricted exercise

“…Nine studies measured acute testosterone responses following LL-BFRRE compared to FFRE in the initial (n = 7), intermediate (n = 6), and late (n = 4) post-exercise time intervals. 35,[44][45][46]70,71,74,76,78 No differences in testosterone plasma levels were observed in the initial (SMD = 0.35 [95% CI −0.34, 1.05]) and intermediate (SMD = 0.55 [95% CI −0.26, 1.36]) post-exercise phase when comparing LL-BFRRE to overall FFRE. Subgroup analysis on load intensity did not demonstrate any difference at the initial and intermediate post-exercise time intervals between LL-BFRRE and LL-FFRE or HL-FFRE, respectively.…”

“…Thirteen studies investigated the acute GH response at either one or all timepoints at the initial (n = 11), intermediate (n = 9), and late (n = 7) post-exercise phase following acute bouts of LL-BFRRE compared to FFRE. 35,[43][44][45][69][70][71][72][73][74][75][76][77] There was no difference in GH plasma production in the initial post-exercise phase (SMD = 0.64 [95% CI -0.23, 1.51]), whereas significant differences 2. Subgroup analysis for study design was performed where only randomized controlled and crossover trials were included in the analysis (excluding non-randomized trials).…”

Blood Flow Restriction Training

“…A body of evidence suggests that low intensity resistance training (LIRT) with BFR (LIBFR) has the ability to produce hypertrophy based outcomes that exceed LIRT without BFR, and are similar to moderate to high intensity resistance training (MHIRT). [5][6][7] Explanations for these outcomes likely reside in the molecular and cellular benefits of applying a BFR tourniquet during training, which by way of a hypoxic effect and the accumulation of metabolites and cell swelling mimics a high intensity environment. While MHIRT possesses a specificity to sports or activities that require greater muscle activation that lower intensity training does not, it is clear that adding LIBFR is a desirable option for those individuals with a low exercise tolerance such as patient populations and those undergoing surgical and orthobiologic procedures.…”

“…The benefits of LIBFR range from acute hormonal responses and acute phosphorylation of proteins involved in hypertrophy signaling pathways (e.g., mammalian target of rapamycin pathway [mTOR]) to the expression of ribosomal RNA transcription factors, increases in biomarkers associated with satellite cell activity, and mRNA expression of genes related to skeletal muscle mass regulation (e.g., MuRF1). 5,6,[8][9][10][11][12][13][14][15] Moreover decreased bone resorption markers, increased interleukin-6 (which may assist with skeletal muscle remodeling) and vascular endothelial growth factor (VEGF), and increased blood lactate occur from LIBFR. 11,13,15,16 A majority of the evidence for acute hormonal secretions following LIBFR is related to growth hormone secretions.…”

“…In one study, a HIRT program was compared to LIBFR for 10-adults who performed squats and chest presses using both programs. 6 Blood samples were collected at baseline, immediately after, and 15-minutes after completion of the exercise routine. The results indicated that the LIBFR program was associated with significantly greater growth hormone serum concentrations at the 15-minute assessment when compared to the HIRT group.…”