The objective of this study was to analyze the blood pressure (BP) response during two isometric exercises — IHG and IWS — to assess their safety in older adults with resistant hypertension (defined as BP that remains above the management goal despite the use of three different antihypertensive agents at maximum or maximally tolerated doses, or controlled BP on four or more antihypertensive agents).
In this repeated measures crossover study, 9 patients aged 66 to 75 underwent an acclimatization session (in which the procedures were explained, data were collected and the intensity of IHG and IWS was assessed) followed by 3 randomly assigned experimental sessions: a control session, an IHG session (4 reps x 2 min, alternating hands, at 30% of maximal voluntary contraction, with 1 min of rest between reps), and an IWS session (4 reps x 2 min, maintaining the squat position at a knee angle of 95% of peak heart rate achieved during the initial IWS incremental test, with 2 min of rest). BP was measured before, during each rep (at 30 and 90s), and after each session.
Most participants were female (66.7%) with a baseline BP of 122 (115–156) / 66 (61–69) mmHg. BP increased throughout contraction time and repetitions, peaking in the final repetition of both IWS and IHG. Significant differences in systolic BP (SBP) and diastolic BP (DBP) were found between IWS and IHG at most points, with higher changes to baseline in IWS (e.g., last rep: 63/27 vs 36/12 mmHg, p.05). Two participants showed excessive BP elevations (i.e. SBP>220 mmHg and/or DBP>105 mmHg) in the IWS session, with one of the participants even surpassing SBP/DBP values of 250/115 mmHg. Four participants (44.4%) had mild side effects (skin irritation, myalgia).
IHG and IWS exercises led to significant BP increases, with IWS producing greater responses. While most participants tolerated the exercises, two showed excessive BP elevations during IWS. Mild side effects were reported by four participants. These findings suggest the need for caution when prescribing isometric exercises, especially IWS, in patients with resistant hypertension.
The findings raise concerns about the safety of isometric exercise, particularly IWS, in individuals with resistant hypertension due to excessive BP elevations observed during IWS. Although BP returned to baseline post-exercise, close monitoring is essential when implementing these exercises in this population. These results suggest the need for careful consideration in physiotherapy practice and highlight the importance of further research to confirm the safety of isometric exercises in resistant hypertension management.
Resistant Hypertension
Isometric Exercise
