The above is the cover of the issue of ''T'ai Chi magazine " in which the following article on the "Effects of T'ai Chi Ch'uan Practice" by Greg Mucci appeared.

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Excuse my dust but still under construction last update 11-16-96

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Scientific Study Clarifies T'ai Chi Ch'uan Benefits 

By Greg Mucci

In 1986 science took a big step in the understanding of T'ai Chi "Ch'uan. In that year, Dr. Ronald G. Knowlton, Professor of Exercise Physiology at Southern Illinois University (SIU), sanctioned and directed a year long research program aimed at examining the physiological changes people undergo when they perform T'ai Chi.

As a graduate student, I performed this research with the assistance of several other graduate students and the services of nine dedicated T'ai Chi players.

Not to my surprise, out research supported the belief that T'ai Chi is "meditation in motion" as well as confirming a few other features of T'ai Chi.

The Research

We got the idea for this project after reading a report of T'ai Chi physiology research led by Dr. D. Zhou, and the prominent exercise physiologist Dr. Roy J. Shepard at the University of Toronto.

They carried out what was the most up to date research on T'ai Chi physiology (Yang Long Form) in the world, and the first T'ai Chi physiology research in the Western world.

Their study had been preceded by only six rudimentary T'ai Chi studies from China. Monumental as their work was, it had some weaknesses. They did not measure cardiorespiratory fitness (C-R fitness) of the T'ai Chi players they examined.

C-R fitness is the best measure of overall physical fitness. The Toronto study did not compare the physiological process during T'ai Chi with a common standard form of exercise such as walking or cycling.

How could we tell if T'ai Chi does something unique to the body if it isn't compared with a typical form of exercise? there were other measures not present in the Toronto study which would have been revealing.

We decided that the purpose of our study would be to fill out the picture of physiological responses to T'ai Chi Ch'uan by re-doing what the Toronto study did, in addition to measuring some of the things it missed.

Our subjects were six men and three women. These people were dedicated T'ai chi martial artists who were also physically active in bicycling, blacksmithing, archeological field work, hiking, and weight lifting. Table 1 presents some of their physical characteristics.

The most accurate measure of the physical energy used in an activity is the measure of oxygen consumption while one is engaged in the activity. This was the key measure of our study.

Oxygen consumption is also an important C-R fitness measure because an activity must use an adequate amount of physical energy to cause an increase in C-R fitness.

For example, an average man (160 pounds) must consume about 1.6 liters of oxygen per minute (about 1/2 of his maximum capacity to use oxygen) to generate C-R improvements.

Moderate walking would cost him about 1 liter per minute, not enough to generate improvements, while fast walking would cost him 1.75 liter a minute. Jogging would cost him about 2.25 liter per minute.

A woman (125 pounds) may need to consume about 1.15 liter of oxygen per minute (about 1/2 her capacity) to raise her C-R fitness.

Moderate walking would involve an expenditure of 0.7 liter per minute. Moderate jogging may require 1.6 liters per minute.

We used oxygen consumption to measure the C-R fitness levels of our subjects. C-R fitness is really nothing more than a maximum amount of oxygen a person is capable of using. It is an indicator of physical exertion one can endure over an extended period of time.

To find our subjects' limits of oxygen consumption, they pedaled on a cycle ergometer (a laboratory bicycle which measures work loads) near their maximum capacity.

Oxygen consumption was also measured as they performed a typical 26 minute set of the long form of Yang style T'ai Chi (very similar to the form depicted in Jou Tsung Hwa's Tao of T'ai Chi Ch'uan) at a medium level of posture.

This measure was needed to determine if T'ai Chi uses enough oxygen to elicit improvements in C-R fitness. In addition to oxygen consumption, we measured several other physiological processes as discussed below.

Finally, we had our subjects pedal the cycle ergometer at the same level of oxygen consumption as when they had performed T'ai Chi, while we measured the same other physiological processes as we measured during T'ai Chi.

We did this in order to determine by statistical comparison if T'ai Chi had unique physiological responses.

The other measures of physiological processes included stoke volume, breathing, blood pressure, and heart rate.

If T'ai Chi has a substantially different effect on the heart than cycling, this effect should show up in the stroke volume and heart rate. Stroke volume is simply the quantity of blood the heart pumps on each heart beat.

Heart rate was measured as a standard procedure needed to screen our subjects for heart abnormalities and other measures.

We were concerned with the rate, volume and efficiency of breathing during T'ai Chi. Breathing processes ate good indicators of relaxation and meditative states.

When one is deeply relaxed or meditating, breathing is slower and in some cases meditative breathing is more efficient than normal breathing.

"More efficient" means that a greater portion of oxygen has been extracted from each unit of air breathed. Blood pressure normally goes up when one is exercising, and we wanted to see if it acted the same way during T'ai Chi as in conventional activities.

What Did They Find?

Our results, and some results from the Toronto research, are presented on Tables 1, 2, and 3. The SIU subjects appeared to normal, healthy young adults. Through slightly fatter than the Toronto subjects, and other types of athletes, they had respectable C-R fitness levels.

The differences in physiological responses between the SIU males and females were about the same when corrected for their difference in size. The oxygen consumption and breathing efficiencies were nearly identical for the SIU and Toronto males.

This finding is important as it strengthen the credibility of both studies. It suggests that our measurements are correct.

I can offer no explanation for the difference in flexibility, grip strength and breathing rate between the SIU and Toronto males.

However, two differences between the SIU and Toronto males stand out as notable. From tables 1 and 2 we calculate the SIU males breathed at less than half the rate of the Toronto males, and experienced a much smaller blood pressure increase during T'ai Chi (+19/+8 vs. +31/+13).

These differences occurred in spite of both groups consuming the same amount of oxygen and performing at about the same speed. (26 vs. 22 minutes for the form).

Why this dramatic difference in breathing rate and blood pressure increase. The only reasonable explanation is that perhaps the Toronto subjects were performing at a lower level of posture than the SIU subjects.

As one lowers the posture there is a greater amount of muscle tension in the lower back and legs. It is well known to physiologists that this kind of sustained tension brings about an increase in blood pressure without increasing oxygen consumption.

This finding bears some important messages for

T'ai Chi players. First it tells us that playing a form in a low posture may not lead to C-R improvements as some people think.

Even though one can perceive an increase in breathing, heart rate and blood pressure as they lower the form, they are deceive by their own perceptions if there is no increase in oxygen consumption.

Second, due to the dramatic blood pressure increases from low, slow forms, people with blood pressure problems or heart disease might be wise to avoid low styles. It is well known to medical people that exercise induced rises in blood pressure can trigger a heart attack in people with heart problem.

Stroke volume (table 3) heart rate and blood pressure in the SIU T'ai Chi performances were not appreciably different from cycling at the same level of oxygen consumption. This suggests that T'ai Chi does not affect the heart any differently than cycling or walking at the same level of exertion.

The 1.07 liters per minute of oxygen consumption during the Yang long from paced at 26 minutes is similar to that of moderate waking, and is not sufficient to generate improvements in the C-R fitness of healthy young adults.

For C-R improvements to occur, T'ai Chi must be practiced quickly enough to demand at least ½ of one's maximum capacity for oxygen consumption. This guideline has been established on the basis of voluminous exercise research interpreted by the internationally acclaimed American College of Sports Medicine.

Cardio-Respiratory Fitness

Some people believe that the greater one's C-R fitness level is, the healthier one can be. This is a myth. Current scientific and medical opinion suggest that fro generally healthy, non- athletic people, and average level of C-R fitness is quite adequate for health protection.

A much more important health variable is the amount of physical activity one has in everyday life. An abundance of evidence has shown that the rick of heart disease is reduced and longevity is increased in people who lead physically active lives.

Their activity does not have to be vigorous enough to raise their C-R fitness above average level, provided that they spend enough time being active.

But this does not discredit the desirability of raising your C-R fitness level. Why? Because the greater your C-R fitness is, the more capable you are of being active without getting exhausted, since you have energy to spare.

This is very important for those T'ai Chi players who take the martial art seriously. A better than average C-R fitness level provides one with an abundant energy reserve for remaining relaxed and effortless while sparing at a vigorous level.

Do the findings of the SIU and Toronto studies tell us that typical, slow T'ai Chi Ch'uan is not vigorous enough to improve C-R fitness? Not necessarily.

If you are quite old, overweight, have had a long term or chronic illness, or if you have been largely sedentary for years, your C-R fitness level is probably below average. When this capacity is below average and easy to moderate exercise like the 26 minute Yang long form will probably require ½ of your capacity: which is enough to get you started on improving your C-R fitness.

The same slow T'ai Chi is not vigorous enough to improve the C-R fitness of people like the SIU subjects because those people are already quite fit. And then there are highly trained endurance athletes. These people must push themselves to incredible extremes of effort in order to continue improving their C-R fitness.

The point is that as one's C-R fitness improves, one must add to the vigor of the exercise to continue improving their C-R fitness. So, you see, a typical 26 minute set of T'ai Chi is plenty vigorous for the person who is way out of shape, but too effortless to bring about improved C-R fitness in a very athletic T'ai Chi player. More than likely you are somewhere between these two extremes.

So how do you get C-R fitness improvements from T'ai Chi? You would be wise to consult a college level text on physical fitness which will show you in detail how you can estimate your C-R fitness level, and the exercise intensity for raising it.

But to get started I'll give you some rough guidelines. After a brief warmup of stretching, or slow Tai Chi, speed up the slow 20 to 25 minute form to and 8 to 10 minute pace. Repeat the speeded up form two or three consecutive times and cool down with some slow exercise.

Do this three to five times per week. This T'ai Chi should give you about the same C-R fitness results as fast walking. The effect will be enhanced if you try to lengthen your strides as you step, being careful not to hurt yourself. At first, this manner of practice may be sloppy, but don't worry, with a few weeks of practice you will find you can do it with grace, delicacy and relaxation.

Movement Meditation

After digressing so far from the results of this research, I'll proceed to what I feel is its most impressive finding. We found (tables 2 and 3) that as our subjects performed T'ai Chi, their rate of breathing was 33% slower and their breathing efficiency was 11% better than it was when they cycled at an equal level of oxygen consumption.

This finding may not come as ‘news' to seasoned T'ai Chi players, but this evidence of relaxed efficient breathing is of major importance to those of us who would like T'ai Chi to be verified before the scientific and medical communities as a meditative art.

Zen, Yoga, and Transcendental Meditation have achieved this credibility on the basis of abundant research, but T'ai Chi remains a mystery. Its basis of sound research is small and incomplete.

The question, "Can T'ai Chi induce meditative effects? " is still unanswered for the scientific community.

The characteristic of the meditative arts which make them impressive to scientists is their capacity to induce unique, relaxing and beneficial states which rarely occur during ordinary activities.

When measured physiologically, these altered states often show up as reduced breathing rates, and increased breathing efficiencies, as well as distinctive changes in heart rate, stroke volume, oxygen consumption, muscle tension, and brain waves.

The decreased rate of breathing demonstrate by the SIU study, and the increased breathing efficiency shown in both the SIU and Toronto Studies are sound scientific evidence that T'ai Chi can induce a relaxing altered state. The SIU study did not show differences in heart rate and stroke volume, probably due to the physical demands of the T'ai Chi movements. Differences in oxygen consumption between T'ai Chi and cycling could not be shown because this is what held constant, making the comparison to other things possible.

To complete the picture of a unique T'ai Chi meditative effect, future studies would confirm or contradict the finding of the SIU and Toronto studies by measuring the same things again, and by adding to these assessments of the other physiological processes which have been shown to change during meditative states.

These studies should be augmented with educational, motor learning, bio-mechanical, social, and physiological research on T'ai Chi.

I must extend my gratitude to the nine T'ai Chi players, Dr. Knowlton, and the graduate students (most notably Dale Brown and Ron Hetzler) who assisted me. It was only by their devotion of many hours, mostly unpaid, and access to the SIU exercise physiology lab that we were able to conduct this study.

The following research reports provided much of the data for this article.

Brown, D. D.; Mucci, W.G.; Hetzler, R. K. ; & Knowlton, R. G. (In press, 1989). "Cardiovascular and ventilatory responses during the formalized T'ai Chi Ch'uan exercise" in Research Quarterly for Exercise and Sport.

Zhou, D.; Shepard R. J.; Plyley, M.J. & Davis,G.M. (1984) "Cardiorespiratory and metabolic responses during T'ai Chi Ch'uan exercise" in Canadian Journal of Applied Sport Science, 9(1), 7 - 10.

Table 1 : Charateristics of Subjects (averages)

	SIU Men (6)	SIU Women (3)	Toronto Men (11)
Age	34.3	32.7	28
Weight	168	133	157.3
Height	5'9"	5'6"	5'10"
Body Fat %	18	27	14
Years of T'ai Chi	8.3	7.8	5
Blood Pressure	124/83	111/71	116/73
Grip Strength	excellent	excellent	marginal
Flexability	very good	very good	excellent
C-R fitness levels are below
a) millimeters of oxygen/ kg of body weight wt/min	46 (very good)	35 (good)	not tested
b) liters of oxygen/minute	3.5	2.12	not tested

 Table 2 : Physiologic Responses During T'ai Chi (averages)

	SIU Men (6)	SIU Women (3)	Toronto Men (11)
Heart Rate (beats per minute	114	107	not tested
Stroke Volume (millimeters of blood per heartbeat)	97	72	not tested
Blood Pressure	143/91	133/82	147/86
Oxygen Consumption (liter/minute)	1.07	0.65	1.03
Breathing Rate (breathes/minute)	11 (slow)	11 (slow)	23 (normal)
Breathing Efficiency	higher than normal	higher than normal	higher than normal

Table 3 : Comparisons : T'ai Chi vs. Bicycle Riding

	SIU Men (6)	SIU Women (3)
Stoke Volume	same	slightly higher in T'ai Chi
Breathing Rate	Significantly lower in TC than in cycling	Significantly lower in TC than in cycling
Breathing Efficiency	Significantly higher in TC than in cycling	Significantly higher in TC than in cycling