Are Holen
Läkare och psykolog, professor emeritus i medicin vid NTNU. Acems grundare.
Acem Meditation is more relaxing than ordinary rest, and long meditations increase its benefits.
This is demonstrated in Erik Ekker Solberg’s doctoral dissertation on the psycho-biological effects of the technique. His research indicates that Acem Meditation improves work economy, competitive performance, and the ability to manage stress. The effects take place partly whilst meditating, but also after each sitting. Some effects, such as lower blood pressure and higher levels of melatonin, seem to result from regular meditation practice over time rather than during or immediately after each sitting. There appears to be no correlation between the degree of subjective comfort experienced during meditation and objectively observed physiological changes.
The effects of Acem Meditation are complex, encompassing the body, behaviour, the psyche, and existential aspects of life. It is difficult to capture all these effects scientifically, but scientific research can clarify our ideas about the outcomes and the mechanisms involved.
This article, drawing on work published in a PhD thesis by Erik Ekker Solberg, will review the findings of seven scientific studies of the effects of Acem Meditation. The studies are referred to by Roman numerals and identified in Box 1 at the end of this article.
Stress, heart rate and blood pressure
Stress is a problem in modern society. While objective health parameters like greater longevity and reduced infant mortality indicate improved health, subjective parameters such as increases in sick leave suggest the opposite. This discrepancy is sometimes explained by increased levels of stress (Levy 2004).
There is a general consensus that meditation can reduce stress-related problems, and for many people this is the main reason for practising meditation (Shapiro et al. 1998; Holen & Eifring 2007). Scientific research provides a method for exploring the effects of meditation.
One way of studying stress is to observe physiological responses to various stressors. A common measure is the heart rate, which is sensitive to acute stress. The heart rate increases rapidly in stressful situations, mediated via the signal transmitter noradrenaline in the sympathetic part of the autonomous nervous system. The heart rate is also a good measure of the opposite of stress, namely relaxation. Resting heart rate is also a stress parameter, and is sometimes used to disclose overtraining in sports.
Another common stress measure is the blood pressure, which also changes in response to stress. Research indicates that increased activity in the sympathetic nervous system (as when reacting to stress) is the most important direct and indirect cause of elevated blood pressure.
Two hours of heart-rate reduction
In the project “Hemodynamic changes during long meditation” (see reference VI in Box 1) we examined the heart rates of 38 experienced male meditators over the course of a threehour sitting. To register the heart rate several times each minute, they wore heart-rate monitors while meditating, thus enabling us to measure the heart rate during meditation, and not only before and after, as many previous studies have done. We compared their heart rates during the first hour’s meditation to the heart rates of 21 non-meditating employees who sat and rested as comfortably as possible for an hour.
Figure a demonstrates a major decrease in the heart rates of meditators compared to non-meditators. This finding is consistent with several international studies which show that 20-30 minutes of meditation reduce the heart rate (Murphy & Donovan 1997). Why the meditators and non-meditators had different initial heart rates is not entirely clear. When designing the study, we expected the groups to start with roughly equal heart rates. The difference in resting heart rate between meditating and non-meditating people has also been shown in another study (Holmes et al. 1983). One might speculate that meditation not only provides relaxation, but also increases the ability to balance tension, resulting in a lower heart rate during meditation and a higher heart rate outside meditation.
The Figure a also shows that the relaxation process continued for the first two hours of meditation but that there were no significant changes in the third hour. Such findings have not previously been recorded. This is the first study to determine the limit to relaxation during long meditation.
Figure a. Heart rate during three hours of meditation and one hour of rest: the graph shows a steady reduction in heart rate during almost three hours of meditation. A similar trend is not apparent during one hour of rest.
Greater heart-rate stability
Another finding concerns the variation in the heart rate (also known as ‘standard deviation’), i.e., how much the heart rate of each meditator goes up and down from one moment to the next. After only a short period of meditation, this variation was significantly lower in the meditators than in the non-meditators (Figure b). The variation in the nonmeditators remained practically unchanged during their hour of rest.
Physically, both groups were doing the same: sitting comfortably and resting. The differences in heart-rate variation therefore cannot be explained by differences in physical activity, but are probably due to a shift in the balance of the autonomous nervous system towards relaxation during meditation. This suggests that meditation induces the parasympathetic nervous system to gain dominance over the sympathetic nervous system, since activity in the sympathetic nervous system is linked to activity and stress, while activity in the parasympathetic nervous system is linked to rest and relaxation.
Figure b. Individual heart-rate variation during one hour of meditation and one hour of rest: twenty minutes of meditation reduces heart-rate variation and increases heart-rate stability more than ordinary rest. This difference is statistically significant.
An increased understanding of the influences on and changes in the autonomous nervous system would be of great medical interest. Several diseases, such as diabetes and heart problems, are partly caused by so-called “sympathetic overdrive”, when the sympathetic nervous system becomes overactive. Imbalances in the autonomous nervous system also influence our general feeling of well-being.
Subjective sense of comfort
The literature on meditation often suggests that relaxation in meditation is experienced as a feeling of comfort, a “feelgood” effect. However, this does not necessarily work the other way. Many things feel good without being connected to physiological relaxation. At times, relaxation may even temporarily be experienced as uncomfortable. Unpublished data from our studies of long meditation show that objective measures of relaxation, such as reduced heart rate, are in no way associated with the meditator’s subjective feelings of comfort during meditation. The periods of meditation judged by the meditator to be “good” were not necessarily those that yielded the clearest measurements of physical relaxation.
It seems fair to assume that objective physical relaxation reflects the quality of the meditation practice, whether or not this leads to subjective feelings of comfort. If this is correct, approaches to meditation that focus on the actual practice may be more effective than approaches that focus on feelings or states of mind.
Reduced blood pressure
There is only moderate documentation that meditation reduces high blood pressure (Astin, Shapiro et al. 2003). In our study of long meditation, blood pressure did not change during three hours of meditation.
However, this may not be the whole story. Blood pressure was registered in three of our studies (references V-VII in Box 1). In all these studies, blood pressure was lower at the outset for meditators than for non-meditators, and the diastolic blood pressure was significantly lower in two of the studies. This may indicate that meditation lowers the blood pressure, not during each sitting, but as a result of long periods of regular practice.
Improved immune system
The immune system, which consists of various specialised cells in the bloodstream and lymphoid organs, is responsive to stress. We wanted to study whether it also responded to relaxation. In the study “Effect of meditation on immune cells” (reference V), the count of certain immune cells in experienced male meditators running a half-marathon was compared to the same count in non-meditators participating in the same race. The study showed that meditators had fewer lymphocytes than non-meditators.
This finding is difficult to interpret. It is possible that regular practice of meditation influences the number of immune cells in the bloodstream. Whether this has any clinical significance, e.g. whether meditators develop a better immune system, is uncertain; but the finding does suggest that the immune system is in some way involved in the relaxation response triggered by meditation.
Other studies support the theory that the immune system responds to relaxation, and indicate that this may have practical clinical significance. One study showed significantly better immune responses to a particular vaccine among meditators than among those who did not practise regular relaxation (Davidson et al. 2003). To date, however, medical science does not know what an optimal immune system would look like.
Another small study, “Meditation: a modulator of the immune response to physical stress?” (reference IV), explored the immune reaction to strenuous aerobic exercise, so-called maximal workload. The meditators showed a lower increase in one type of immune cells (type CD8+ T cells) than nonmeditators, although both groups were under equal amounts of stress. This finding may indicate that meditation reduces the undesirable effects of intense stress on the immune system.
Increased ability to handle stress
Many studies demonstrate that meditation increases relaxation. But how useful is relaxation? Do the relaxation effects obtained from meditation influence our ability to handle stress?
One way to explore this is to examine blood lactate resulting from muscle work. Pain and stiffness after intense strain reflect an increase in lactate following muscle training. Deposits of blood lactate after exercise are reduced by a period of meditation (Wallace & Benson 1972). Does regular practice of meditation also decrease production of lactate in response to muscle strain?
In the study “Stress reactivity to and recovery from a standardised exercise bout: a study of 31 runners practising relaxation techniques” (reference II), recreational runners were randomly assigned to one of three groups. One of the groups learnt Acem Meditation, one learnt autogenic training (a goal-orientated relaxation technique), and one was given lectures on sport psychology. Before and after the sixmonth test period, blood samples were drawn from the runners before, just after and ten minutes after a bout of running on a treadmill. The results showed that lactate decreased significantly more in meditators than in those practising autogenic training or in the control group receiving sport psychology lectures (see Figure c).
The fact that meditators produce less lactate while performing the same workload as non-meditators may mean that meditation improves work economy. This would imply that meditators consume less energy than non-meditators, analogous to a car that maintains the same speed as other cars while using less petrol. Another study has yielded similar findings (Caird et al. 1999).
Our study compares the effects of two different relaxation techniques, Acem Meditation and autogenic training. While Acem Meditation is a nondirected (process-oriented) technique based on a free mental attitude, autogenic training is a directed (goal-oriented) technique based on concentration. Those who learnt Acem Meditation showed significantly greater reductions in post-exercise lactate than those who learnt no relaxation technique at all. Those who learnt autogenic training showed some reduction in post-exercise lactate, but it was not statistically significant. This may indicate that nondirected relaxation techniques such as Acem Meditation are more efficient than directed techniques such as autogenic training.
Figure c. Average reduction in lactate from before relaxation training until six months after: regular meditation may reduce the accumulation of lactate more than other methods of rest or relaxation.
Improved performance
One type of stress management is the ability to cope with the stresses associated with competition. Several studies indicate that mental exercise techniques improve performance in different types of sports (Greenspan & Feltz 1989; Vealey 1994; Weinberg & Comar 1994).
Originally, we wanted to study an “ordinary” meditator’s ability to manage stress while coping with the “ordinary” demands of his or her daily schedule. Our question was: Would meditation influence the ability to manage everyday stress? With the methods available, however, this was difficult, and instead, we chose to investigate the effect of Acem Meditation on elite shooters (reference I). The results of shooting are precise and easy to measure. At the same time, shooting performance is sensitive to variations in tension.
Twenty-five elite shooters were randomly allocated to two different groups. One group learnt Acem Meditation; the other did not. Their performance was measured in two different settings: in test shootings during practice and in real competitions. The test shootings took place just before and after the period during which one of the groups learnt and practised meditation. Competition results were measured during the seasons before and immediately after the meditation period. To calculate shooting performance, we used a mean of the three best competitions, a longstanding method in shooting circles. On average, each shooter participated in 27 competitions in the season immediately after the meditation period.
Figure d. Average change in competitive shooting results from the season before meditation training to the season after: elite shooters who learnt Acem Meditation improved their results, while the non-meditating group did less well.
As shown in Figure d, the competitive shooting results of meditators improved from the season before learning meditation to the season after. In the same period, the non-meditators’ results declined. The non-meditators attributed their lower results during the second season to poor weather, which in turn means that the meditators’ performance improved in spite of adverse conditions.
Interestingly, there was no difference between the groups in the test shootings, only in the competitions. The explanation is probably that test shootings did not stress the shooters to the same extent as competitions. This implies that meditation did not so much improve shooters’ technique as increase their ability to handle competitive stress.
Low tension improves performance
Immediately after each test-shooting session at the beginning and the end of the project, before their results were announced, shooters were asked to score their level of tension on a scale from 1 to 7, in which 1 indicated low tension and 7 high tension. In Figure e (see next page), each dot represents a combination of shooting result (vertical axis) and self-rated tension (horizontal axis).
The Figure e shows that low self-rated tension is associated with good shooting results. Good results may also occur at high levels of tension, but less consistently so.
Calculations of the so-called variation coefficient showed that tension accounted for as much as 18% of the variation in shooting performance. This is considerable, since the elite shooters had already undergone extensive training and practice to enhance their performance, and one would expect the scope for further improvement to be limited. There is a clear implication that tension significantly influences performance. Studies of anxiety-related tension indicate that the anxiety level itself may not be the most important factor, but rather the feeling of control over the anxiety. All these findings suggest that working with mental states, in order to reduce and/or manage tension, is an effective means of improving performance.
Figure e. Correlation between self-rated tension and shooting performance: higher perceived tension correlates with poorer shooting results. The line depicts an approximated average curve.
Lower levels of melatonin
Effortless mental repetition of a meditation sound seems to induce physical relaxation and recovery, but how does this happen? Which signal systems in the body are involved, and what are the actual causal mechanisms?
Scientists have suggested the following explanations:
- increased activity in the relaxing part of the autonomous nervous system (Barnes et al. 2001)
- reduced level of stress hormones (Infante et al. 2001)
- changes in the metabolism of the brain (Davidson et al. 2003; Lazar et al. 2000).
A role has also been attributed to the neurohormone melatonin, which among other things induces sleep and has many metaregulating effects on the body. Studies have shown that meditators have higher levels of melatonin than non-meditators (Massion et al. 1995), and the level of melatonin increases during one hour of meditation starting at midnight (Tooley et al. 2000). Prior to our research, however, melatonin production had not been studied after morning meditation, which is when most people meditate. Nor had it been studied in relation to long meditation. Accordingly, our studies measured melatonin before, during and after three hours of Acem Meditation starting at 9 a.m. (reference VII). The meditators were compared to a group of non-meditators resting for one hour.
The findings show higher initial levels of melatonin among Acem meditators than among non-meditators. This accords with other research data and supports the assumption that long-term meditation influences the melatonin metabolism. Melatonin may also be one of the possibly numerous mediators eliciting relaxation responses in the body.
Figure f. Melatonin during three hours of meditation and one hour of rest: meditators start out with higher levels of melatonin than non-meditators. Melatonin levels decrease steadily during three hours of meditation, but do not change during ordinary rest.
While melatonin levels in the non-meditators showed no change during their hour of rest, the level of melatonin in the meditators decreased sharply during all three hours of meditation.
Melatonin concentrations in the blood vary significantly, reaching a peak during the night and being much lower during the day. Our findings may suggest that meditation practised regularly over time influences our biological clock. The marked reduction of melatonin levels during three hours of meditation is interesting, but difficult to explain.
Our study also measured the level of the signal transmitter serotonin in the blood before, during and after meditation. In contrast to melatonin, serotonin behaved in the same way in meditators as in non-meditators. The substance seems to be a general marker of relaxation unspecific to meditation. In other words, the relaxation induced by meditation does not seem to be based on a general reduction in neurohormonal activity, but rather involves specific signal systems in the brain, in which melatonin, but not serotonin, plays an important role.
Long-term effects
Several of our studies showed that experienced meditators and non-meditators had physiological differences from the outset, despite the application of selection criteria intended to level out such differences. These findings may reflect inadvertent selection bias, but are more likely to be related to the long-term effects of regular meditation.
This brings up an interesting question: When do the effects of meditation appear? During meditation, immediately after meditation, or after a long time – months and years – of regular meditation? It is often assumed that the effects of meditation are most pronounced during a sitting. However, one study showed that the effects may be more salient after meditation (Wallace & Benson 1972), while another suggested that they build up over a prolonged period of regular meditation (Davidson et al. 2003). In this regard, meditation may be similar to physical training, which has long-term, cumulative benefits for physical condition. What are the effects of practising meditation on a regular basis? Does meditation influence the ability to manage stress? In other words, are there links between repeated regular relaxations and better stress reactivity over time? It is far more difficult to explore this question scientifically than it is to analyse the immediate effects of 30 minutes of meditation, because when the observation period is that much longer, other factors may also play a part. Perhaps as a consequence of this difficulty, the time-dimension has received too little attention in international meditation research, but both our data and other studies suggest that the long-term effects of meditation may be even more important than the short-term effects.
Qualified optimism
Many methodological issues arise in the interpretation of our findings and those produced by other research on meditation. In addition, our results can be interpreted in alternative ways.
Like other international research projects on meditation, our studies are relatively small, the number of participants varying from 12 to 49. The low proportion of female participants may be seen as a shortcoming, but it may also be a methodological strength, since it helps reduce unwanted hormonal variations and makes the population more homogenous.
There are also problems in designing valid comparative studies involving meditators and non-meditators. For instance, it is not obvious what form of non-meditative rest provides the best point of comparison with meditation: ordinary relaxation, sitting quietly, sleeping, or some other type of behaviour? In our studies, we chose optimal nonmeditating rest.
As a proportion of overall medical research, there are relatively few studies on the effects of meditation. The central medical database, PubMed, contains more than 100,000 publications on “atherosclerosis”, but only about 5000 articles on “relaxation techniques”. Compared to what we know about other medical conditions, the body of scientific knowledge about meditation is very limited to date.
We therefore need to exercise some caution in drawing conclusions from the studies discussed above. Nevertheless, the results are promising. To recap: Acem Meditation seems to give better relaxation than ordinary rest, as shown by the reductions in both the heart rate and the variation in heart rate during meditation; melatonin may be one of the neurohormones inducing relaxation effects; though blood pressure was not affected during three hours of meditation, experienced meditators had significantly lower blood pressure to start with; and some studies indicate that Acem Meditation reduces stress reactivity, increases work economy, and improves competitive performance.
The future will show what place meditation may have in modern society and to what extent positive health and stress-management effects will inspire people to practise meditation.
Dr. Erik Ekker Solberg’s dissertation on Acem Meditation
Solberg EE (2004). Psychobiological effects of meditation. University of Oslo. PhD thesis.
The dissertation includes the following seven articles published in peer-reviewed international medical journals:
(I) Solberg EE, Berglund KA, Engen O, Ekeberg O, and Loeb M (1996). The effect of meditation on shooting performance. Br J Sports Med 30: 342-346
(II) Solberg EE, Ingjer F, Holen A, Sundgot-Borgen J, Nilsson S, and Holme I (2000). Stress reactivity to and recovery from a standardised exercise bout: a study of 31 runners practising relaxation techniques. Br J Sports Med 34: 268-272
(III) Øktedalen O, Solberg EE, Haugen AH, and Opstad PK (2001). The influence of physical and mental training on beta-endorphin level and pain perception after intensive physical exercise. Stress and Health 17: 121-127
(IV) Solberg EE, Halvorsen R, Sundgot-Borgen J, Ingjer F, and Holen A (1995). Meditation: a modulator of the immune response to physical stress? A brief report. Br J Sports Med 29: 255-257
(V) Solberg EE, Halvorsen R, and Holen A (2000). Effect of meditation on immune cells. Stress Med. 16: 185-190
(VI) Solberg EE, Ekeberg O, Holen A, Ingjer F, Sandvik L, Standal PA, and Vikman A (2004). Hemodynamic changes during long meditation. Appl Psychophysiol Biofeedback 29: 213-221
(VII) Solberg EE, Holen A, Ekeberg Ø, Østerud B, Halvorsen R, and Sandvik L (2004). The effects of long meditation on plasma melatonin and blood serotonin. Med Sci Monit 10: CR96-101 The following eight points sum up effects of Acem Meditation as documented by Erik Ekker Solberg’s doctoral dissertation.
1. Acem Meditation provides relaxation
Both heart rate and heart rate variation are reduced during meditation. The effect increases during the first two hours of long meditation.
2. Acem Meditation improves performance under stress
Shooters who learn Acem Meditation improve their performance significantly compared to shooters who do not learn to meditate. The difference does not apply during training sessions, only in competitions, which involve higher degrees of tension.
3. Acem Meditation helps the body to work with greater ease
Recreational runners produce less lactate during training after having learnt Acem Meditation.
4. Nondirected techniques give better results than directed techniques
The effect on lactate deposits was more pronounced in Acem Meditation, which is a nondirected, process-oriented technique, than in autogenic training, which is a directed, goal-oriented technique.
5. Acem Meditation may help reduce a mildly elevated blood pressure
Experienced meditators seem to have a lower blood pressure than non-meditators. Their blood pressure is not reduced further during three hours of meditation.
6. Acem Meditation reduces negative effects of stress on immune system
The increase in CD8+ T cells (a type of immune cell) during intensive muscle training is more moderate in meditators than non-meditators. Meditators also have fewer lymphocytes (another type of immune cell) in their blood than nonmeditators.
7. Acem Meditation influences the levels of melatonin in the blood
Experienced meditators have higher levels of melatonin than non-meditators. The level of melatonin falls sharply during meditation, but not during ordinary rest.
8. ”Feeling good” is unrelated to physiological effects of Acem Meditation
The objective relaxation effects of meditation are unrelated to the subjective experience of comfort and well-being during meditation. ”Feeling good” alone is not a valid measure of the quality of the physiological changes produced by the practice.