Intensity-dependent reductions in resting blood pressure following short-term isometric exercise training

Abstract

Word count 2,781 ABSTRACTRecently, a minimum threshold of training intensity for reducing resting blood pressure (RBP) after short-term isometric exercise training (IET; < 4wks) had been suggested.However, variations in IET protocols employed are evident, including different methods for setting training intensity. Therefore, the minimum IET intensity required for RBP adaptations to occur, after short-term IET programs, is not known. Purpose: The purpose of this study was to compare the effects of short-term moderate-and lowintensity IET programs on RBP in normotensive subjects. Methods and Results: 3wks of IET at 30%EMG peak resulted in significant reductions in RBP (e.g. -3.9 ± 0.99 mmHg, P<0.001, mean arterial RBP) whereas IET at 20%EMG peak did not (-2.3 ± 2.9 mmHg; P>0.05, mean arterial RBP). However, within the 20%EMG peak training group, systolic RBP in female subjects was significantly lower than their male counterparts following IET (105.8 ± 3.0 vs. 123.6 ± 3.0 mmHg for women and men respectively). Conclusions:Results confirmed previous predictions that an IET intensity of 20-30%EMG peak is required to elicit a significant RBP reduction in a short-term training period (3-4wks). In addition, sex differences may exist in the magnitude of reductions. This may be important in understanding the mechanisms responsible for this established phenomenon.

The efficacy of ‘static’ training interventions for improving indices of cardiorespiratory fitness in premenopausal females

“…The significant reduction in SBP in our IHG group mirrors the findings of Gill et al who observed a 6.9-mmHg reduction in SBP in normotensive females after 3-weeks of isometric exercise training (IET) (Gill et al 2015). However, Gill et al employed bilateral leg extensions as their mode of IET, thus recruiting a much larger muscle.…”

Home-based isometric exercise training induced reductions resting blood pressure

“…The current findings (in agreement with Devereux et al 2010) elucidate an intensity dependent continuum of resting blood pressure adaptation whereby Baross et al (2012) reported no significant differences in any RBP parameters at 4 weeks when bilateral-leg extension was performed at an intensity of 85% HRpeak, but significant reductions in SBP and MAP at the end of 8 weeks; whereas Gill et al (2015) showed that all parameters of resting BP were significantly reduced after only 3 weeks of bilateral-leg IET, but only when IET occurred at a higher intensity (~100% HRpeak or 34%MVC) than previously used.…”

“…The resting BP reductions are similar in magnitude to those previously reported following IET that was partly laboratory-based with participants performing constant force contractions (McGowan et al 2007a;Millar et al 2013a) and completely laboratory-based using constant EMG contractions (Devereux et al 2010;Wiles et al 2010;Gill et al 2015). Furthermore, the rate of reduction in all resting BP parameters occurred at either a faster or equal rate (Devereux et al 2010) to that reported previously in normotensive participants following bilateral-leg IET using the same acute programme variables and exercise intensity in a laboratory setting.…”

“…Currently the results obtained following 4 weeks of isometric wall squat training are in agreement with a growing number IET studies using larger muscle mass lower body exercise that have been able to produce reductions in all three BP components (SBP, DBP, MAP) following ≤8 weeks of isometric leg training (Devereux et al 2010and Gill et al 2015. However, all of these previous studies used bilateral-leg extension that required specialised equipment only available in a small number of sport and exercise science laboratories around the country.…”

The use of the CR-10 scale to allow self-regulation of isometric exercise intensity in pre-hypertensive and hypertensive participants

“…Evidence for the blood pressure (BP) lowering effects of isometric exercise is growing (Börjesson et al 2016). To date, studies have reported that isometric exercise lowers BP in healthy adults (Wiley et al 1992;Ray and Carrasco 2000;Howden et al 2002;Millar et al 2008;Wiles et al 2010;Devereux et al 2011;Badrov et al 2013a; Devereux and Wiles 2015;Gill et al 2015), hypertensive (non-medicated and medicated) and pre-hypertensive adults (Wiley et al 1992;Taylor et al 2003;McGowan et al 2006;Peters et al 2006;McGowan et al 2007b; Baross et al 2012;Baross et al 2013;Millar et al 2013;Badrov et al 2013b).…”