Novel isometric handgrip device lowers blood pressure
The IsoBall (IB), a novel isometric exercise device, elicits improvements in systolic (SBP) and diastolic (DBP) blood pressure and in mean arterial pressure (MAP), according to a new study.
“The primary aim of this study was to evaluate the concept and efficacy of the prototype IB using the widely studied [isometric handgrip (IHG)] training protocol against a commercially available equivalent [Zona ball (ZON)],” said researchers.
The study included 23 healthy adults (mean age, 29.10±2.19 years; 13 males) who were randomly assigned to undergo IHG training either using the IB (n=7) or ZON (n=8) devices or to a control group (n=8). Analysis of covariance revealed a significant pre-to-postintervention change in SBP (P=0.000). [Open Access J Sports Med 2019;10:89-98]
Subsequent posthoc Bonferroni tests found that the significant differences were between the IB (119±7.0 mm Hg; p=0.000) and ZON (114.5±8.2 mm Hg; p=0.000) arms vs the control group (131.0±12.4 mm Hg). Both IHG arms resulted in comparable levels of change in SBP (p=0.620).
Moreover, individual standardized response data found that IB yielded a trivial to very large effect on SBP (0.62±0.66), while ZON resulted in moderate to very large (0.72±0.28) changes.
Similar effects were reported for DBP. Both IB (65.7±10.0 mm Hg; p=0.012) and ZON (66.6±7.4 mm Hg; p=0.004) groups had significantly lower postintervention DBP than their control counterparts (71.1±8.8 mm Hg), but not relative to each other (p=1.00). Individual DBP responses were trivial to large in the IB group (0.46±0.43 mm Hg) and small to large in the ZON group (0.56±0.34 mm Hg).
IHG exercises likewise elicited a significant effect on MAP. Participants who underwent training with the IB (84.3±9.1 mm Hg; p=0.000) and ZON (82.6±6.8 mm Hg; p=0.000) devices showed significantly reduced MAP as compared with their control counterparts (91.0±9.7 mm Hg). Between-intervention differences were null (p=0.750).
In terms of individual responses, ZON slightly outperformed IB, with effects ranging from small to very large vs trivial to large (0.63±0.54 vs 0.50±0.43 mm Hg).
“Despite the ZON eliciting larger BP reductions in all parameters, the nonsignificant differences between the two devices confirm the hypothesis that both devices would elicit similar significant BP reductions compared to control,” researchers pointed out.
No significant differences were observed for other parameters, including heart rate and strength in the right and left handgrips.
“One aspect of the IB that differentiates it from other [isometric exercise] devices is its versatility,” researchers explained. “The IB device can be attached to any ball via a needle valve adaptor; this enables the shape and size of the ball to be changed allowing for a wide variety of possible exercises to be performed.”
This may have important implications on adherence, they continued, as participants cite lack of time, location, difficulty and boredom as common reasons that inhibit them from sticking with an exercise regimen. “All of these factors are overcome with [isometric exercise] as the interventions used require a short time commitment, at a low intensity and can be performed virtually anywhere.”
“Therefore, the IB device should be further tested and used in future studies as a diverse, low-cost and portable method for controlling IE intensity aimed at reducing BP,” researchers added.