Isometric Exercise Training May Lower Blood Pressure With Just Two Sessions a Week

Exercise is widely known to support health, yet regular workouts are not always practical because of limited time, motivation or mobility. Scientists are therefore investigating activities that deliver the greatest gains with the smallest investment of time and effort.

A new study in BMJ Open Sport & Exercise Medicine, led by researchers at Canterbury Christ Church University in the UK, identifies isometric exercise training (IET) as an approach that can lower blood pressure with only a couple of sessions each week.

IET includes any exercise in which a position is maintained for several minutes. Examples include remaining in a squat, holding a plank, or performing a hand-grip exercise.

These activities are straightforward, take little time and need no equipment. The researchers say they could be a valuable alternative for people unable to complete longer, more wide-ranging exercise routines.

Isometric exercise training and blood pressure

During the study, IET was associated with reductions in systolic blood pressure: the upper figure in a measurement such as 130/85. This number represents the highest pressure in the arteries when the heart pumps blood out, as well as overall average arterial pressure.

"Lower-frequency IET can help maintain short-term blood pressure reductions, providing a pragmatic option for individuals with limited time or adherence challenges," write the researchers in their published paper.

Earlier research had already linked IET with lower blood pressure. However, until now, researchers had not closely examined the amount required, including the duration and frequency needed to achieve the greatest benefits.

For this study, the team enrolled 100 adults with an average age of 37. They were not meeting minimum exercise recommendations and had normal to high-normal systolic blood pressure, within the 120–140 mm Hg range.

Wall squats performed over eight weeks

For the first four weeks, 80 volunteers were instructed to complete wall squats three times weekly, doing four squats per session. The remaining 20 participants formed a control group. During the following four weeks, those in the exercise group were told either to continue with three weekly sessions or reduce their schedule to two sessions, one session or none.

After four weeks, the exercise group’s systolic blood pressure had fallen by an average of 9.45 mm Hg relative to the control group. Among participants who continued three sessions a week for the full eight weeks, the average reduction rose to 13.73 mm Hg.

People who cut back to two sessions or one session recorded an overall average reduction of roughly 6.5–7 mm Hg after eight weeks. In contrast, participants who stopped exercising after four weeks saw their blood pressure return to its earlier level four weeks later.

"For optimal blood pressure reductions and the maintenance of a broader range of physiological adaptations, a frequency of three times per week may be recommended," write the researchers.

The findings provide strong support for IET’s blood-pressure benefits. After four weeks, systolic blood pressure, diastolic blood pressure and mean arterial pressure had all improved significantly compared with the control group, although training frequency did not produce a meaningful difference in the results.

Why IET may support cardiovascular health

The researchers suggest that these exercises could relax and widen blood vessels while shifting the nervous system into a calmer state. More detailed studies over longer periods will be required to establish this with certainty.

"While causality cannot be confirmed, the observed alignment between the mechanistic decline and the loss of blood pressure reduction suggests that training frequency plays a critical role in sustaining the cardiovascular adaptations necessary for blood pressure control following IET," write the researchers.

The team further proposes that continuing IET for longer than a couple of months could produce genuine structural changes affecting blood pressure. If so, the benefits might not vanish immediately once exercise ends, as they did in this study.

The results are another indication that improving fitness and maintaining better health through exercise does not necessarily require large amounts of activity.

"[The study] may inform policy discussions around feasible, scalable exercise interventions for populations with low adherence or limited exercise tolerance," write the researchers.

The research has been published in BMJ Open Sport & Exercise Medicine.

This article was fact-checked by Rachel Garner and edited by Fiona MacDonald. Although we take pride in our process, we are only human. If you notice an error, please let us know.