Effect of isometric handgrip exercise training on resting hemodynamics: a pilot study.

OBJECTIVE: The purpose of the present study was to examine 1) whether Isometric Handgrip (IHG) training lowers arterial pressure at rest and 2) whether possible reductions in arterial pressure are associated with reductions in the heart rate variability (HRV).

METHODS: This case series consisted of 2 hypertensive female subjects who were trained with four 3-minute bouts of IHG) exercise at 30% maximal voluntary contraction (MVC) separated by 5-minute rest periods. Training was performed 4 times per week for 4 weeks. Subjects' resting arterial pressure were measured before and after training each day for 4 consecutive days, with HRV recorded on the third day each week.

RESULTS: In the first subject, resting diastolic pressure decreased from 120 to 90 mmHg and systolic arterial pressure decreased from 160 to 140 mmHg, whereas heart rate increased from 52 to 55 beats/min, and HRV did not change following training. The decrease in blood pressure was seen after 3 weeks of handgrip exercise. In the second subject, no trend of blood pressure reduction was seen but the systolic arterial pressure decreased before and after the handgrip exercise at 10 training days out of the 17 possible days. In the other 7 days, 6 days showed no blood pressure changes after handgrip exercise. The HRV in the LF, HF, VLF ranges did not change with training.

DISCUSSION: Handgrip exercise moderately reduced blood pressure in the 2 female hypertensive subjects. The reduction of blood pressure and response to HRV seemed to relate to subject's history of using hypertensive medication.

CONCLUSION: IHG training might be an effective nonpharmacological intervention in lowering arterial pressure. Further study is needed.