A martial art for the heart: tai chi outperforms aerobic exercise for blood pressure reduction Original paper

In this randomized controlled study, tai chi improved systolic blood pressure to a larger degree than aerobic exercise among adults with prehypertension.

The effects of tai chi versus aerobic exercise on blood pressure in adults with prehypertension.

The primary outcome was the change in systolic blood pressure. Secondary outcomes included the change in diastolic blood pressure, ambulatory blood pressure (24-hour, daytime, and nighttime systolic and diastolic blood pressure), blood lipids (LDL, HDL, total cholesterol, triglycerides), cardiometabolic risk factors (fasting glucose, HbA1c, creatinine, waist circumference, body weight, BMI), the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36), the Systematic Coronary Risk Estimation (SCORE), and any adverse events that occurred during or after the exercise sessions.

342 adults from China (average age of 49; 166 men and 176 women) who had prehypertension (defined as a systolic blood pressure of 120–139 mmHg and a diastolic blood pressure of 80–89 mmHg).

In this 12-month randomized controlled study, the participants were assigned to a tai chi group or an aerobic exercise group.

Both groups performed exercise 4 times per week for 60 minutes per session, which comprised a 10-minute warmup, 40 minutes of training, and a 10-minute cooldown.

The tai chi group performed 24-form Yang-style tai chi, and the aerobic exercise group performed stair climbing, jogging, brisk walking, and cycling (or a combination of these modalities) at a intensity corresponding to 55%–70% of their age-predicted maximum heart rate (i.e., 208 − 0.7 x age).

Some of these exercise sessions were performed in a group and some were performed alone. Some were supervised while others were recorded by participants and uploaded to the research staff.

The outcomes were measured at baseline, 6 months, and 12 months.

Systolic blood pressure decreased (improved) by 7 mmHg in the tai chi group and by 4.6 mmHg in the aerobic exercise group at 12 months compared to baseline. The change in systolic blood pressure was larger in the tai chi group by 2.4 mmHg compared to the aerobic exercise group.

At 6 months, systolic blood pressure decreased by 6.2 mmHg in the tai chi group and by 4.9 mmHg in the aerobic exercise group. The change was 2.3 mmHg larger in the tai chi group.

Both groups experienced similar decreases in diastolic blood pressure at 6 and 12 months.

Tai chi also led to a larger reduction in 24-hour ambulatory systolic blood pressure (2.2 mmHg) and nighttime systolic blood pressure (4.1 mmHg) compared to the aerobic exercise group.

None of the other outcomes differed between groups.

Tai chi reduces systolic blood pressure more than aerobic exercise

The evidence is growing in support of tai chi as an effective, low-impact, enjoyable, and heart-healthy form of exercise.

In a previous meta-analysis of 24 randomized controlled studies, tai chi improved systolic and diastolic blood pressure.^[1] In addition, tai chi led to improvements in quality of life, general health, bodily pain, vitality, social functioning, mental health, physical health, and emotional health. In addition, a 2020 meta-analysis of 126 randomized controlled trials looked at 22 nondrug interventions for reducing blood pressure, and found that tai chi stood out as among the most effective, although the evidence quality was very low.

The research on the specific mechanisms for how tai chi helps reduce blood pressure is still in its early stages, but some studies suggest that the answer lies in the autonomic nervous system. One particular study observed the immediate effects of tai chi on older adults and found that tai chi appeared to tip the balance of their autonomic nervous system. Instead of leaning toward sympathetic modulation (which can raise blood pressure), it leaned more towards parasympathetic modulation (which can help reduce it).^[2]

In another study, the blood-pressure-lowering effects of a 12-week tai chi program were attributed to reductions in a hormone called angiotensin II and increases in nitric oxide (NO).^[3] Angiotensin II causes blood vessels to constrict, causing an increase in blood pressure. In contrast, NO dilates blood vessels, causing a reduction in blood pressure.^[4]

These results add to the growing body of evidence that various types of exercise — not just aerobic exercise — can benefit blood pressure. A recent meta-analysis of exercise trials was reviewed in this Editor’s Pick, in which aerobic exercise, resistance training, high-intensity interval training, and isometric exercise all reduced systolic blood pressure by 5–8 mmHg and diastolic blood pressure by 3–4 mmHg. In fact, isometric exercise was found to be the most effective exercise for reducing blood pressure.

Tai chi has many similarities to isometric exercise: it focuses on static or relatively static postures and use of the body’s own weight through slow, smooth movements to strengthen muscles, tendons, and ligaments and increase flexibility. In light of this, the results of this study aren’t too surprising.

In the tai chi group, 31% of the participants had blood pressure that fell within the recommended range of less than 120 (systolic) and 80 (diastolic) at the end of the study. In the aerobic exercise group, 22% of the participants fell within range. The percentage of participants with hypertension (systolic and diastolic blood pressure above 140 mmHg or 90 mmHg, respectively) was lower in the tai chi group (12%) compared to the aerobic exercise group (18%).

Finally, 35% of the participants in the tai chi group and 28% in the aerobic exercise group experienced a reduction in systolic blood pressure of 10 mmHg or more. In terms of diastolic blood pressure, 44% of the participants in the tai chi group and 37% in the aerobic exercise group had a reduction of 5 mmHg or more. However, the difference in these percentages was not statistically significant.

Ambulatory blood pressure monitoring involves the out-of-office 24-hour measurement of blood pressure using at-home devices, and it’s more closely related to cardiovascular complications than in-office blood pressure measurements.^[5] The improvement in 24-hour and nighttime systolic blood pressure in the tai chi group may be of great clinical significance, though it should be noted that these were exploratory outcomes.

Of note, some parameters related to mental health (measured using the SF-36,) did improve from baseline in the tai chi group: general health increased by 5 points, mental health increased by 4 points, social functioning increased by almost 3 points, role-emotional increased by 5 points, and vitality increased by almost 3 points. There were no changes from baseline in the aerobic exercise group. Although more research needs to be done, these results suggest that tai chi may be an effective intervention for improving cardiovascular health and mental health in adults.

Tai chi seems to represent an effective, zero-cost, and low-barrier alternative to traditional aerobic exercise for blood pressure reduction. This martial art may very well benefit the heart.

The authors drew attention to the fact that all of the secondary outcomes — including the significant findings regarding 24-hour and nighttime systolic blood pressure — should be considered exploratory and interpreted with caution. Furthermore, this study did not analyze the effects of each intervention in participants with different levels of blood pressure, which may have helped to identify which groups may benefit most from tai chi and/or aerobic exercise.