Recent evidence has demonstrated that isometric handgrip training may improve resting arterial blood pressure. The current study evaluated the ability of simple, spring handgrips to reduce resting arterial blood pressure in normotensive participants using an 8-week randomized controlled design.
Forty-nine (age: 66 ± 1) participants, 28 female and 21 males were recruited. All participants completed 5 pre-training sessions, used to familiarize and assess baseline blood pressure, heart rate and maximal hand strength. Maximal hand strength was assessed by three bilateral, maximal contractions with a hand dynamometer. Blood pressure and heart rate were assessed with an automated acquisition system. Participants were stratified to control and intervention groups based on baseline age and blood pressure by matched-pair randomization.
Participants in the training condition (n = 25) completed 8 weeks of thrice weekly handgrip training at approximately 30% of their baseline maximal hand strength using a spring handgrip. Seated blood pressure and heart rate were assessed prior to each training session following 10 minutes of isolated rest. Training included 4, 2-minute contractions separated by 2 minutes of rest and completed bilaterally. Control participants (n = 24) completed weekly-seated measurements of blood pressure and heart rate following 10 minutes of isolated rest. Following 8 weeks of intervention all participants completed 3 sessions of post-training measurements.
In trained participants, resting systolic and diastolic pressure decreased significantly from pre- to post- (SBP: 122 ± 3 mmHg to 112 ± 3 mmHg, DBP: 70 ± 1 mmHg to 67 ± 1 mmHg) while heart rate remained unaltered. Pulse pressure was significantly reduced with handgrip training, from 52 ± 3 mmHg to 45 ± 3 mmHg. Control participants demonstrated no changes in blood pressure, heart rate and pulse pressure, over the course of the study.
In conclusion, spring handgrip training results in significant decreases in systolic, diastolic and pulse pressure. The mechanisms behind these improvements remain unknown and require further investigation.