Key result
Inspiratory muscle exercise at 40% of maximal inspiratory pressure did not significantly change systolic blood pressure compared to sham (-4±2 vs -1±2 mmHg; P=0.27), but increased heart rate.
Why the study?
Literature regarding hemodynamic responses during inspiratory muscle exercise lacked consensus.
Does inspiratory muscle exercise with 40% maximal inspiratory pressure alter hemodynamic responses compared to sham exercise in healthy sedentary men?
RCT (n=15)
randomized
Does inspiratory muscle exercise with 40% maximal inspiratory pressure alter hemodynamic responses compared to sham exercise in healthy sedentary men?
p-value: p=0.27
Inspiratory muscle exercise with a 40% resistive load increases heart rate more than sham exercise in healthy sedentary men, without significantly altering blood pressure or cardiac output.
IME at 40% MIP yields similar BP and most hemodynamic responses to sham in healthy men; leaves open effects in clinical populations.
The literature on hemodynamic responses during inspiratory muscle exercise (IME) lacks a consensus. To evaluate and compare hemodynamic responses during an IME session with and without resistive load, 15 sedentary men were subjected to two randomized IME sessions: one with 40% of maximal inspiratory pressure (IME 40%) and another without a resistive load (Sham), both of which were performed for two minutes over eight sessions with one-minute intervals. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), total peripheral resistance (TPR), stroke volume (SV), cardiac output (CO), and heart rate (HR) were measured by infrared digital photoplethysmography during five basal minutes and during the IME sessions. One-way analysis of variance and the Student’s t test for paired data were used to analyze hemodynamic response and delta values between sessions. Effect size was evaluated by Cohen’s D. A 5% significance level was adopted. SBP responses (sham: ∆−1±2 vs. 40%: ∆−4±2mmHg, p=0.27), DBP (sham: ∆2±1 vs. 40%: ∆1±2mmHg, p=0.60) and MBP (sham: ∆2±1 vs. 40%: ∆0±2mmHg, p=0.28) were similar between sessions. HR increases were higher in the 40% IME session than in the sham session (sham: ∆9±2 vs. 40%: ∆3±2bpm, p=0.001). SV only decreased during the sham session but responses were similar between sessions (sham: ∆−2±2 vs. IME 40%: ∆−6±2ml, p=0.13). Both sessions did not change SBP, DBP, MBP, CO, and TPR, but we observed a greater increase in HR in the IME 40% session. Only the Sham session decreased SV.
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Moreira et al. (2023) conducted an RCT in Healthy sedentary (n=15). Inspiratory muscle exercise (IME) at 40% of maximal inspiratory pressure vs. IME without resistive load (Sham) was evaluated on Hemodynamic responses including systolic blood pressure (p=0.27). Inspiratory muscle exercise at 40% of maximal inspiratory pressure did not significantly change systolic blood pressure compared to sham (-4±2 vs -1±2 mmHg; P=0.27), but increased heart rate.
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