Influence of breathing strategies on maximal strength output and hemodynamic parameters during bench press exercise

Abstract

Background The role of breathing strategy during high-intensity resistance training remains underexplored in the literature, particularly in relation to performance outcomes and cardiovascular modulation. This study aimed to examine the acute effects of three distinct breathing techniques—inhalation, exhalation, and breath-holding (Valsalva maneuver)—on performance parameters and heart rate variability (HRV) during maximal bench-press exercise in resistance-trained males. Methods Twelve healthy, non-smoking male participants (age: 27.92±7.38 years), with at least two years of consistent isotonic resistance training experience, were recruited. Exclusion criteria included chronic disease and prior or current use of hormone-based substances. Each participant completed three testing sessions in a counterbalanced order, with one breathing condition applied per session. Breathing techniques were standardized via instructional videos and monitored during testing. Performance was assessed by the total number of sets completed and total volume lifted (kg). Cardiovascular responses were measured via a Holter monitor for HRV parameters—standard deviation of normal-to-normal intervals (SDNN), root mean square of successive differences (RMSSD), percentage of NN intervals differing by >50 ms (pNN50), low-frequency power (LF), high-frequency power (HF), and LF/HF ratio— and heart rate. Blood pressure was recorded at three time points: pre-exercise, after the third set, and post-exercise. Statistical analyses included the Friedman test, Dunn–Bonferroni post hoc, and Kendall’s W for effect size. Results Breathing strategy had a statistically significant effect on SDNN (χ² = 6.00, p=0.05, W=0.273), while other HRV and blood pressure measures showed no significant changes (p>0.05). Performance metrics differed significantly across conditions, with inhalation resulting in lower set completion (χ² = 13.86, p<0.001, W=0.578) and training volume (χ² = 13.07, p<0.001, W=0.544). Conclusion Breathing technique influenced both autonomic and performance responses. Inhalation during lifting was associated with reduced performance and lower SDNN values. These findings are preliminary and limited by small sample size and the use of a single exercise modality.