High and low intensity resistance training both acutely lower blood pressure in treated hypertension

This randomized clinical trial examined acute cardiac autonomic responses and blood pressure changes following resistance training in 31 adults with pharmacologically treated hypertension. Participants completed a single session of either high intensity resistance training (80% of 1RM) or low intensity training (40% of 1RM), with both protocols matched for total training volume. Measurements were taken before and immediately after exercise.

Both training intensities produced significant reductions in blood pressure, though exact numerical values were not reported. No significant interaction between training intensity and any measured variable was observed (p > 0.05). Cardiac parasympathetic indices showed significant reductions, with the low intensity protocol demonstrating a more pronounced cardiac autonomic response characterized by greater vagal withdrawal.

Correlation analyses indicated a positive association between changes in the V1% heart rate variability index and blood pressure reductions, and a negative correlation between low frequency heart rate variability and blood pressure. Safety and tolerability data were not reported. Key limitations include the small sample size of 31 participants, acute measurements only, and the correlational nature of the autonomic findings, which preclude causal interpretation. The study provides preliminary evidence that both high and low intensity resistance training can acutely lower blood pressure in this population, but long-term effects and clinical significance remain uncertain.