Changes in Heart Rate Variability and Post-Exercise Blood Pressure from Manipulating Rest Intervals Between Sets of Resistance Training.

The purpose of this study was to compare blood pressure and heart rate variability responses in physically active men after performing resistance training sessions with rest intervals of 1 min, 2 min and 3 min. Eighteen men (age, 21.6±1.1 years; body mass, 74.1±8.1 kg; body height, 175.3±7.1 cm) who performed 180min of physical activity per week participated in this study. After determining the 15RM loads for the squat, bench press, bent-over row and deadlift, participants performed a resistance training session. Participants performed three resistance training protocols in randomized counterbalanced order. Each experimental protocol comprised different rest intervals between sets of resistance training exercises (1min, 2min or 3min). During each experimental session, participants performed three sets with a 15RM load. Blood pressure and heart rate variability were measured before and for 2h after each session. The results demonstrated a greater blood pressure (p<0.05) reduction with a longer rest interval. There was no statistically significant difference in heart rate variability changes between groups. These results indicate that 2min and 3min rest intervals while using a 15RM load provide the best stimulus for a blood pressure reduction response after a resistance training session. Our findings suggest that strength and conditioning professionals should prescribe 2min or 3min rest intervals when resistance training is performed with a 15RM load if the aim is to obtain an acute reduction in blood pressure after a resistance training session.