Muscle Excitation During Volume-Equated Squats Performed With and Without Blood Flow Restriction

Authors

Danielle Hitchens, University of North TexasFollow
Joshua L. Keller, University of North TexasFollow
Kase Pennartz, University of North TexasFollow
Wonjae Lee, University of North TexasFollow
Jeremiah Blough, University of North TexasFollow
Myungjin Jung, University of North TexasFollow
Jiwon Song, University of North TexasFollow

Abstract

Blood flow restriction (BFR) resistance training has gained increasing attention in clinical, athletic, and recreational settings. It has been proposed that low-load resistance exercise combined with BFR can elicit significant muscle adaptations, potentially mimicking the effects of high-load training. Despite the growing use of this modality, the effects of BFR on muscle excitation remain incompletely understood., Surface electromyography (EMG) provides a useful approach for examining these responses. Additionally, volume-matched exercise conditions are needed to isolate the unique effects of load and BFR. PURPOSE: Therefore, the purpose of this study was to determine whether muscle excitation differs across four sets of volume-equated squats performed under three conditions: Low load (LL), LL + BFR, and High load. METHODS: Twenty-nine recreationally active healthy adults (n=15, male; age: 24± 5; height: 168.6 ±8.8cm; body mass: 72.2 ± 12.7kg; % body fat: 22.9 ±9.0%) completed all three volume-matched experimental conditions. Muscle excitation was recorded from the right vastus lateralis using surface EMG and calculated as root mean square (RMS) amplitude across all squat repetitions, with set-level averages computed. The two low-load conditions consisted of 1 × 30 and 3 × 15 repetitions (75 total) at 30% one-repetition maximum (1RM), whereas the high-load condition consisted of 4 × 8 repetitions (32 total) at 70% 1RM. For the BFR condition, cuffs were inflated to 40% of the minimal pressure needed to occlude each femoral artery. A 3 (Condition: High, LL, LL + BFR) × 4 (Set: 1–4) repeated-measures ANOVA was used to examine differences in EMG RMS across sets, with significant effects followed by post-hoc t-tests. A pRESULTS: No significant Condition × Set interaction was observed (p=0.095, η²ₚ= 0.072), and there was no main effect of Set (p =0.596, η²ₚ= 0.017); however, a significant main effect of Condition was found (p =0.001, η²ₚ= 0.263). Post hoc comparisons indicated that muscle excitation in the High condition was significantly greater than in LL + BFR (p= 0.030, d = .573) and LL conditions (p= 0.002, d = 0.751), whereas BFR and LL were not significantly different (p= 0.340, d= 0.178). CONCLUSION: LL resistance exercise, with or without BFR, does not differentially influence muscle excitation, whereas high-load exercise is associated with greater responses. These findings may reflect greater motor unit recruitment under heavier absolute loads, consistent with the size principle. Future work is needed to confirm these patterns using more direct measures of motor unit behavior . Clinically, this has important implications for rehabilitation and training programs aimed at maximizing muscle excitation and strength.

Recommended Citation

Hitchens, Danielle; Keller, Joshua L.; Pennartz, Kase; Lee, Wonjae; Blough, Jeremiah; Jung, Myungjin; and Song, Jiwon (2026) "Muscle Excitation During Volume-Equated Squats Performed With and Without Blood Flow Restriction," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 40.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/40