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High blood pressure, or hypertension, remains a global health challenge, with a soaring prevalence (thanks in part to changing definitions of hypertension) and control often proving elusive. It remains one of the leading modifiable risk factors for disease and death worldwide. While lifestyle interventions have long been a mainstay in hypertension management, a growing body of research underscores the particularly pivotal role of exercise training as an effective non-pharmacological antihypertensive strategy. Recent findings, including a large-scale systematic review and meta-analysis of 270 randomised controlled trials, shed new light on the optimal exercise practices for managing blood pressure. 

Exercise as a Cornerstone of Hypertension Management:

The link between exercise and cardiovascular health is certainly not a novel concept. Regular physical activity has long been associated with reduced risks of heart disease and hypertension. However, contemporary research is refining our understanding of how different exercise modalities impact blood pressure.

The Landmark Study:

Led by Dr. Jamie J. Edwards and a team of researchers from Canterbury Christ Church University in the United Kingdom, this comprehensive study published in the BJSM examined the effects of various exercise training modes on resting blood pressure. The study analysed 270 randomised controlled trials published between 1990 and February 2023, involving a total of 15,827 participants.

Key Findings:

The study’s results paint a clear picture of the effectiveness of different exercise modalities in reducing both systolic and diastolic blood pressure:

• Aerobic Exercise Training: This traditional form of exercise demonstrated significant reductions in resting systolic blood pressure (SBP) by an average of 4.49 mm Hg and diastolic blood pressure (DBP) by 2.53 mm Hg.
• Dynamic Resistance Training: Participants engaging in dynamic resistance training experienced reductions in SBP and DBP by an average of 4.55 mm Hg and 3.04 mm Hg, respectively.
• Combined Training: Combining aerobic and resistance training led to even more pronounced reductions, with SBP decreasing by 6.04 mm Hg and DBP by 2.54 mm Hg.
• High-Intensity Interval Training (HIIT): HIIT, known for its time-efficient, intense bursts of activity, lowered SBP by 4.08 mm Hg and DBP by 2.50 mm Hg.
• Isometric Exercise Training (IET): This novel form of exercise emerged as the most effective, resulting in a substantial reduction of SBP by 8.24 mm Hg and DBP by 4.00 mm Hg.

Optimal Exercise Modes:

The study ranked the exercise modalities based on their effectiveness, with isometric exercise training (IET) topping the list, boasting a Surface Under the Cumulative Ranking Curve (SUCRA) value of 98.3 percent. Surface Under the Cumulative Ranking Curve, or SUCRA, is a statistical tool used in network meta-analysis to evaluate the relative effectiveness of several different interventions or treatments. In the context of this study, SUCRA values were used to assess and rank the various exercise modalities in terms of their impact on resting blood pressure.

A higher SUCRA value indicates a greater likelihood that a particular intervention (in this case, an exercise modality) is the most effective among the options being compared. In other words, a higher SUCRA value suggests that an exercise mode is more consistently and confidently ranked as the best choice for reducing blood pressure. Combined training followed closely at 75.7 percent, dynamic resistance training at 46.1 percent, aerobic exercise training at 40.5 percent, and high-intensity interval training (HIIT) at 39.4 percent.

The Isometric Advantage:

Isometric exercise training, particularly through activities like isometric wall squats, emerged as the most potent submodes for reducing SBP (SUCRA: 90.4 percent) and DBP (SUCRA: 91.3 percent), respectively.

Implementing Isometric Training:

Isometric exercise places the muscle under tension without moving the surrounding joints. To harness the benefits of isometric exercise, use the following protocol:  

4×2-minute contractions, separated by 1–4-minute rest intervals, performed three times a week. 

Isometric handgrip (IHG) is usually executed at 30% maximum voluntary contraction, while isometric wall squats (IWS), also known as ski squats can be performed to elicit a rate of perceived exertion (RPE) between 3.5–4.5/10 for the first bout, RPE 5–6/10 for the second bout, RPE 6.5–7.5/10 for the third bout, and RPE 8–9/10 for the fourth bout. Isometric leg extension (ILE) is performed at 20% of the maximum voluntary contraction (this is the maximum amount of force that can be generated by contracting a muscle group). So in practice, this means holding still with the legs fully straightened approximately 20% of the heaviest hold that you could shift on the leg extension machine. 

As the prevalence of hypertension continues to rise, understanding the role of exercise in its management becomes increasingly critical. The latest research emphasises the varied and substantial benefits of lots of different exercise modalities, with isometric exercise training shining as a particularly potent antihypertensive intervention. Of the isometric exercises, wall squats, to me at least, are the most convenient to perform.

Dr. J. Hugh Coyne

Coyne Medical