New research suggests that exercising just once or twice a week may be enough to maintain some of the blood pressure benefits gained from regular physical activity, at least over a short period. However, people who continue exercising three times weekly may experience larger and more sustained improvements.
The findings, published in BMJ Open Sport & Exercise Medicine, suggest that even a single weekly session of isometric exercise could help people preserve improvements in blood pressure when they cannot commit to a more frequent workout schedule.
Isometric exercise involves tightening muscles while holding the body in a fixed position for several minutes. Common examples include wall squats, planks, and handgrip exercises.
Earlier research has found that isometric training can lower blood pressure more effectively than other types of exercise, sometimes producing reductions comparable to or greater than those achieved with certain medications. However, researchers have not fully understood how often these exercises need to be performed to maintain their cardiovascular benefits.
Testing How Often Wall Squats Are Needed
To investigate, researchers enrolled 100 adults whose average age was 37.4 years. Participants had systolic blood pressure ranging from normal to high-normal levels (120-140 mmHg) and did not regularly participate in structured exercise programs.
Under expert guidelines, systolic blood pressure between 130 and 139 mmHg falls into the “high-normal” category, which warrants specific lifestyle recommendations from healthcare professionals. None of the participants had been diagnosed with hypertension.
To qualify, volunteers had to be free of injuries and illnesses, have no current or previous use of blood pressure medication, and be nonsmokers. They also had to consume no more than 14 units of alcohol per week.
Participants were randomly assigned to five groups. One served as a control group, while the other four began the same four-week exercise program at home, focusing on isometric movements involving the lower body.
The training consisted of four wall squat holds per session, with two minutes of seated recovery between each hold. Participants completed this routine three times weekly during the first four weeks.
After this initial training period, the four exercise groups followed different schedules for another four weeks. One continued with three weekly sessions, another reduced its frequency to twice weekly, and a third performed the exercises only once a week. The fourth group stopped training altogether.
Researchers evaluated blood pressure, heart rate, and additional measures of cardiovascular function at the beginning of the experiment and again after four and eight weeks.
Even One Weekly Workout Helped Preserve Blood Pressure Benefits
After the first four weeks, all four exercise groups showed significant improvements compared with the control group. These included reductions in systolic blood pressure, which measures pressure when the heart contracts, and diastolic blood pressure, which measures pressure when the heart relaxes. Mean arterial pressure, a measure of average blood pressure throughout the cardiac cycle, also decreased significantly.
These initial results were consistent with earlier studies demonstrating the blood pressure benefits of isometric exercise. However, after participants switched to their assigned maintenance schedules, the groups no longer showed statistically significant differences in diastolic blood pressure.
By the end of the eight-week study, participants exercising just once or twice weekly had maintained significant reductions in systolic blood pressure and mean arterial pressure compared with the control group. Neither schedule maintained a statistically significant improvement in diastolic blood pressure.
The greatest benefits appeared among participants who continued performing wall squats three times per week. Their systolic blood pressure fell by an average of 13.73 mmHg (-13.73 mmHg) from the beginning of the study.
By comparison, the twice-weekly group experienced an average reduction of 6.95 mmHg, while participants exercising once a week recorded a decrease of 6.56 mmHg.
Those who maintained the three-session schedule also preserved improvements in other cardiovascular measurements, including total peripheral resistance (an indication that blood vessels have narrowed) and heart rate variability.
Stopping Exercise Caused Blood Pressure Benefits to Fade
The results also revealed what happened when participants stopped exercising completely.
Those who discontinued wall squats after the initial four weeks experienced a reversal of their earlier blood pressure improvements. By the end of the study, their readings were no longer statistically different from those of the control group.
This finding suggests that maintaining some level of regular isometric exercise may be important for preserving the cardiovascular improvements gained during training.
However, the researchers emphasized that the maintenance phase lasted only four weeks. Additional studies following participants for longer periods will be needed to determine whether less frequent training can preserve these benefits over months or years.
“The study demonstrates that while lower frequency isometric exercise training may be sufficient to maintain blood pressure reductions over the short term, higher frequencies are required to preserve these benefits and the associated vascular and cardiac autonomic adaptations,” the researchers write.
“The study offers evidence that lower frequency isometric exercise training can help maintain short-term blood pressure reductions, providing a pragmatic option for individuals with limited time or adherence challenges.”
