(40) Hemodynamic Responses to Moderate and High Intensity Leg Press and Squat Resistance Exercise

Purpose: Arterial stiffness and blood pressure responses are crucial indicators of disease and predictors of cardiovascular complications. While several studies have noted increased stiffness and pressures during resistance exercise, limited research explores how varying intensities and exercise modalities acutely affect these responses. Additionally, there is a scarcity of data comparing recreationally active and sedentary adults. This study aimed to assess the acute impact of different intensities during leg press and squat resistance exercises on central hemodynamics.

Methods: Twelve recreationally active (n=6) and sedentary (n=6) men and women participated in six trials, including two sessions to determine one repetition maximum (1RM) for squat and leg press. The four randomized trials involved performing 15 reps at 60% 1RM and 8 reps at 80% on both the leg press at moderate (LPM) and high (LPH) intensities, and back squats at moderate (SqM) and high (SqH) intensity. Carotid-femoral pulse wave velocity (cfPWV, arterial stiffness) and aortic systolic (aSBP) and diastolic blood pressure (aDBP) were measured before and after each exercise session, with additional measurements between sets during the recovery period. A two-way analysis of variance with repeated measures planned contrasts was employed to identify differences within and between interventions at baseline, between sets, and post-exercise timepoints.

Results: No significant baseline differences in pressures were observed, although the sedentary group exhibited significantly higher cfPWV at rest (P< 0.001). Moderate intensity elicited a higher aSBP response compared to high intensity, irrespective of the exercise modality. Significantly different responses were noted in the sedentary population between LPM/SqM and LPH/SqH (P< 0.05). Notably, while SqH had minimal impact on pressures, it significantly affected cfPWV in the sedentary population.

Conclusion: Our data indicates that high-intensity, low-volume resistance exercise results in a augmented pressor response compared to moderate intensity, high-volume resistance exercise, particularly in sedentary adults. Practical Application: Current resistance training recommendations favor moderate intensity and high volume for untrained individuals. However, our findings suggest potential cardiovascular risks, especially for individuals with undiagnosed underlying conditions.

Acknowledgements: None