D I S S E R T A T I O N I N B R I E F

Progressive Muscle Relaxation, Breathing Exercises,and ABC Relaxation Theory

Ä

Mia Matsumoto and Jonathan C. SmithRoosevelt University Stress Institute

This study compared the psychological effects of Progressive Muscle Relax-ation (PMR) and breathing exercises. Forty-two students were divided ran-domly into two groups and taught PMR or breathing exercises. Both groupspracticed for five weeks and were given the Smith Relaxation States Inven-tory before and after each session. As hypothesized, PMR practitionersdisplayed greater increments in relaxation states (R-States) Physical Relax-ation and Disengagement, while breathing practitioners displayed higherlevels of R-State Strength and Awareness. Slight differences emerged atWeeks 1 and 2; major differences emerged at Weeks 4 and 5. A delayedand potentially reinforcing aftereffect emerged for PMR only after fiveweeks of training—increased levels of Mental Quiet and Joy. Clinical andtheoretical implications are discussed. © 2001 John Wiley & Sons, Inc. JClin Psychol 57: 1551–1557, 2001.

Keywords: ABC relaxation; breathing exercises; Jacobson; meditation;progressive muscle relaxation; relaxation response; yoga

Progressive Muscle Relaxation (PMR; Jacobson, 1929) and breathing exercises are usedwidely in clinical and health psychology (Smith, 1999a). Although considerable researchhas examined the efficacy of PMR, relatively little has focused on breathing as a specificapproach (Bernstein, Borkovec, & Hazlett-Stevens, 2000; Lehrer & Woolfolk, 1993). Noresearch has compared both approaches. Different perspectives of relaxation have differ-ent predictions for the effects of both techniques. Benson (1975) has hypothesized that allrelaxation techniques evoke a nonspecific relaxation response of reduced sympatheticarousal. Davidson and Schwartz’s (1976) cognitive/somatic specificity hypothesis pos-tulates two major categories of arousal and relaxation, cognitive and somatic. Both hypoth-

This study was completed by the first author as a Master’s thesis in partial completion of the requirements forthe master’s degree in Clinical Psychology at Roosevelt University.Correspondence concerning this article should be addressed to: Jonathan C. Smith, Director, Roosevelt Uni-versity Stress Institute, 430 S. Michigan Ave., Chicago, IL 60605.

JOURNAL OF CLINICAL PSYCHOLOGY, Vol. 57(12), 1551–1557 (2001)© 2001 John Wiley & Sons, Inc.

eses predict that PMR and breathing are somatic techniques that should be equally effectivein reducing somatic arousal and physical symptoms; indeed, most clinicians who usethese techniques assume technique equivalency (Smith, 1999a). However, Smith’s (Smith,1999a, 1999b) Attentional Behavioral Cognitive (ABC) relaxation theory proposes thatthe effects of PMR and breathing exercises should be quite different.

ABC relaxation theory is a comprehensive, empirically based psychological theoryof relaxation. In developing his perspective, Smith started with an exhaustive catalog of400 words used to describe experiences people have while practicing or engaging inactivities generally accepted as relaxation (progressive muscle relaxation, autogenic train-ing, yoga, breathing exercises, imagery, creative visualization, tai chi, self-hypnosis, med-itation, contemplation, and prayer). Through a series of eight separate factor analyticstudies involving a combined sample of 2616 participants, Smith and his colleagues(Smith, 2001) identified what are currently 15 (or “141 1”) relaxation state (R-State)categories: Sleepiness, Disengagement, Physical Relaxation, Mental Quiet, Rested/Refreshed, At Ease/Peace, Positive Detachment (manifested as Childlike Innocence),Energized, Joy, Thankfulness and Love, Mystery, Awe and Wonder, Prayerfulness, andTimeless/Boundless/Infinite. The fifteenth R-State, Aware, is a metastate that can existeither alone or in combination with other states.

According to ABC relaxation theory, all approaches to relaxation involve sustainingpassive simple focus—for PMR, the focus is tensing up and letting go; for breathing, it isthe flow of breath, and so on. However, techniques differ dramatically as to which R-Statesthey evoke. To date, over 30 studies involving over 9000 participants provide substantialsupport for this perspective (Smith, 2001) and has revealed major differences amongrelaxation techniques; notably, practitioners of progressive muscle relaxation consis-tently recall feeling Disengagement and Physical Relaxation, whereas breathing and yoga-stretching practitioners recall Strength and Awareness (now termed Energized). However,such retrospective research has serious limitations. Do relaxers accurately recall within-session experiences? Do recollections accurately reflect pre-post session changes?

The present study attempts to compare directly the R-States evoked by PMR andbreathing. We hypothesized that five weeks of PMR will increase significantly R-StatesPhysical Relaxation and Disengagement, whereas five weeks of breathing exercises willincrease R-State Strength and Awareness.

Method

Participants

Participants consisted of 42 undergraduate college students (14 males, 28 females, aver-age age5 19.55,sd5 0.57; PMR age5 19.79,sd5 .61; breathing age5 19.35,sd5 .43).Five males and 16 females were assigned to breathing relaxation and 9 males and 12females to PMR. All participants completed training and filled out questionnaires. Allcompleted the entire five-week program, and all applicable APA guidelines were followed.

Instruments

All participants took the Smith Relaxation States Inventory (SRSI; Smith, 2001), an earlyversion consisting of 25 self-report items that tap ten R-States (Sleepiness, Disengage-ment, Physical Relaxation, Mental Quiet, At Ease/Peace, Strength and Awareness, Joy,Love and Thankfulness, Prayerfulness, and Timeless/Boundless/Infinite) and three stress

1552 Journal of Clinical Psychology, December 2001

states (somatic stress, worry, negative emotion); this version does not tap R-States Rested/Refreshed Relaxation, Positive Detachment (Childlike Innocence), Mystery, or Awe andWonder. A state format was deployed in which participants indicated how they currentlyfelt at the present moment using 6-point Likert scale (15 not at all, 65 the most ever).Chronbach’sa reliabilities range from .60 to .88 (Smith, 2001).

Procedure

Participants were assigned randomly to two groups, progressive muscle relaxation anddeep breathing. Instructions for both were read (by MM) directly from standardizedscripts offered by Smith (1999b). The presenter was not blind to the hypotheses, a majorlimitation of this study. Each exercise sequence was approximately 30 min in length androughly equivalent in complexity. Specifically, Smith’s scripts attempt to provide “pure”versions of techniques reflecting only one attentional strategy. Thus, PMR incorporatesonly tensing up and letting go (without accompanying breathing, stretching, or imageryinstructions often included in popular versions of PMR). Breathing exercises incorporateonly attention to the flow of breath. The entire script of eleven PMR exercises and twelvebreathing exercises were included.

Each group met with the experimenter (MM) for five consecutive weekly sessionsand practiced the assigned 30-min exercise as she read instructions. Participants did notpractice at home. For Weeks 1 and 5, questionnaires were administered three times through-out the session: immediately prior to practice (pretest), immediately following practice(posttest), and three min after the posttest (aftertest). During the 3-min pause, partici-pants were instructed to think casually about the forthcoming day and week’s activities).For Weeks 2, 3, and 4, the SRSI was given immediately before and after relaxation.

Results

Over five weeks, a sequence of 12 tests were given (5 weekly pretests; 5 weekly post-tests; and 2 aftertests, one for Week 1 and one for Week 5). Repeated measures analysesof variance (ANCOVAs) were conducted on the sequence of 11 tests given after Week 1pretest (yielding a total of 4 pretests, 5 posttests, 2 aftertests); covariates included test 1(Week 1 pretest) scores (for each variable under consideration), gender, and age. Fivehighly significant GroupX-Week interactions emerged for which there were significantpairwise comparisons (p 5 .05): PMR participants scored higher on Disengagement[F(10,16)5 16.03,p 5 .0005], Physical Relaxation [F(10,16)5 17.72,p 5 .0005],Mental Quiet [F(10,17)5 8.85, p 5 .0005], and Joy [F(10,17)5 9.79, p 5 .0005].Breathing participants scored higher on Strength and Awareness [F(10,16)5 10.29,p 5.0005]. No other analyses reached statistical significance (p . .05). See Table 1 formeans and standard deviations and Table 2 for summary of all repeated measuresANCOVAS.

Pairwise comparisons were conducted for each test time (pretest, posttest, and after-test for each of five weeks) for R-States Disengagement, Physical Relaxation, MentalQuiet, Strength and Awareness, and Joy. At Week 1 aftertest, PMR practitioners scoredmodestly higher (p # .05) on Physical Relaxation [F(1,40)5 11.94,p 5 .001] and atWeek 2 on Physical Relaxation and Disengagement [F(1,40)5 6.23,p 5 .02]. At Week1, breathing practitioners scored modestly higher on Strength and Awareness [F(1,40)57.25,p 5 .01].

Pronounced differences on Disengagement and Physical Relaxation did not emergeuntil the very end of training at Weeks 4 and 5 [F(1,40)5 14.48,p 5 .0005]. At Week 5

Progressive Muscle Relaxation and Breathing Exercises 1553

Table 1Means and Standard Deviations for Progressive Muscle Relaxation andBreathing Participants on All Variables

R-State Pretest Group Week 1 Week 2 Week 3 Week 4 Week 5

Sleepiness PMR 5.48 (2.94)* 5.48 (2.84) 5.00 (2.61) 5.86 (2.87) 5.33 (2.50)Breathing 4.86 (2.54) 3.57 (1.29) 4.90 (2.02) 4.24 (1.34) 3.52 (1.91)

Disengagement PMR 4.76 (1.76) 5.35 (1.65) 5.14 (1.80) 5.96 (1.56) 5.52 (1.63)Breathing 4.33 (2.06) 3.67 (1.77) 4.33 (2.03) 4.38 (2.01) 4.29 (2.37)

Physical Relaxation PMR 4.76 (1.97) 5.33 (1.65) 5.24 (2.05) 5.71 (1.79) 6.00 (1.58)Breathing 4.90 (1.89) 3.52 (0.87) 4.14 (1.74) 4.19 (1.57) 4.71 (1.82)

Mental Quiet PMR 4.57 (1.47) 4.71 (1.76) 5.10 (1.79) 5.24 (2.02) 6.14 (1.93)Breathing 4.33 (1.39) 3.62 (1.63) 3.62 (1.47) 4.19 (5.24) 6.24 (1.64)

At Ease/Peace PMR 6.76 (1.45) 6.81 (1.69) 6.57 (1.50) 6.48 (1.69) 6.52 (1.99)Breathing 5.81 (1.25) 5.38 (1.32) 5.38 (1.96) 6.14 (1.68) 5.90 (2.51)

Strength and Awareness PMR 6.14 (1.80) 6.10 (1.76) 6.19 (1.69) 6.24 (2.10) 6.38 (2.01)Breathing 5.30 (1.45) 5.52 (1.36) 5.81 (1.83) 6.14 (2.03) 6.05 (2.09)

Joy PMR 6.19 (1.94) 6.33 (1.91) 6.79 (2.02) 6.29 (2.61) 6.52 (1.99)Breathing 5.38 (1.43) 5.71 (0.78) 5.19 (1.75) 5.24 (2.07) 5.90 (2.50)

Love and Thankfulness PMR 6.52 (2.09) 6.67 (0.48) 7.19 (2.29) 6.67 (2.61) 6.38 (2.01)Breathing 6.24 (1.92) 6.48 (0.51) 5.81 (1.69) 5.90 (1.58) 6.04 (2.08)

Prayerfulness PMR 2.19 (1.12) 2.43 (1.29) 2.81 (1.44) 2.76 (1.51) 2.57 (1.36)Breathing 1.67 (1.02) 1.57 (0.98) 1.76 (1.00) 1.71 (1.01) 1.96 (1.06)

Timeless PMR 2.14 (0.96) 2.45 (1.23) 2.24 (1.22) 2.67 (1.20) 2.33 (1.07)Breathing 2.05 (1.28) 1.85 (0.88) 1.81 (0.81) 1.76 (0.70) 1.81 (1.16)

Physical Stress PMR 6.19 (3.14) 5.48 (1.75) 5.67 (2.76) 4.62 (2.01) 4.33 (1.71)Breathing 7.14 (2.41) 6.33 (1.53) 6.10 (1.79) 4.95 (1.40) 4.95 (0.92)

Worry PMR 2.24 (1.37) 1.95 (0.92) 1.76 (0.89) 2.05 (1.24) 2.00 (1.00)Breathing 3.00 (1.00) 3.14 (0.96) 2.38 (1.02) 1.90 (0.89) 2.47 (.87)

Negative Emotion PMR 5.76 (2.81) 4.86 (1.49) 4.33 (1.24) 4.47 (1.17) 4.33 (1.71)Breathing 6.43 (1.78) 5.95 (1.20) 4.48 (1.21) 4.76 (1.09) 4.95 (.92)

R-State Posttest

Sleepiness PMR 6.33 (2.92) 5.52 (2.62) 6.62 (3.17) 6.76 (3.36) 5.86 (2.22)Breathing 4.19 (1.83) 4.48 (1.36) 5.00 (2.70) 4.76 (2.78) 4.24 (1.22)

Disengagement PMR 6.62 (2.42) 7.19 (1.29) 7.33 (2.37) 8.00 (1.84) 7.90 (1.61)Breathing 5.33 (1.85) 5.81 (2.18) 6.33 (2.01) 6.24 (2.59) 5.57 (1.94)

Physical Relaxation PMR 8.62 (1.72) 8.81 (2.14) 9.38 (1.72) 9.86 (1.53) 10.24 (1.64)Breathing 7.33 (2.63) 7.19 (2.09) 7.62 (2.58) 7.29 (2.41) 7.81 (2.42)

Mental Quiet PMR 6.57 (1.83) 6.53 (2.06) 6.62 (2.67) 6.33 (2.24) 6.62 (2.18)Breathing 6.62 (1.77) 6.05 (2.64) 5.67 (2.67) 6.24 (2.64) 5.81 (2.23)

At Ease/Peace PMR 7.62 (1.80) 7.62 (1.99) 7.62 (2.16) 7.76 (2.00) 7.71 (1.93)Breathing 7.76 (1.61) 7.48 (1.89) 7.33 (2.11) 7.57 (1.78) 7.71 (1.68)

Strength and Awareness PMR 6.57 (1.75) 7.38 (2.46) 7.00 (2.28) 6.71 (2.08) 6.95 (2.18)Breathing 7.90 (1.45) 8.19 (1.89) 7.57 (2.18) 8.14 (2.06) 8.38 (2.20)

Joy PMR 6.62 (1.75) 7.10 (2.43) 7.19 (2.23) 6.81 (2.68) 7.62 (2.29)Breathing 5.81 (1.69) 6.24 (1.84) 6.14 (1.65) 6.48 (1.75) 6.52 (1.50)

Love and Thankfulness PMR 5.95 (2.48) 6.81 (2.44) 7.38 (2.16) 7.29 (2.15) 7.05 (2.56)Breathing 6.86 (1.68) 7.00 (1.86) 6.90 (1.84) 6.62 (1.86) 6.90 (1.97)

Prayerfulness PMR 2.52 (1.36) 2.81 (1.40) 2.95 (1.63) 2.90 (1.58) 3.00 (1.52)Breathing 2.10 (1.22) 2.19 (1.25) 2.38 (1.50) 2.19 (1.50) 2.19 (1.36)

Timeless PMR 2.57 (1.25) 2.95 (1.10) 2.86 (1.49) 3.00 (1.48) 3.19 (1.44)Breathing 2.38 (0.97) 2.57 (1.36) 2.33 (0.91) 2.57 (1.08) 2.57 (0.98)

Physical Stress PMR 4.05 (0.97) 3.71 (1.23) 3.81 (1.60) 3.38 (0.80) 3.48 (0.87)Breathing 3.67 (1.39) 3.33 (0.66) 3.81 (1.99) 3.14 (0.36) 3.29 (0.64)

Worry PMR 1.43 (0.60) 1.33 (0.58) 1.38 (0.59) 1.33 (0.58) 1.33 (0.58)Breathing 1.67 (0.91) 1.38 (0.50) 1.38 (0.74) 1.38 (0.92) 1.29 (0.46)

Negative Emotion PMR 4.05 (1.16) 3.67 (0.86) 3.34 (0.51) 3.43 (0.75) 3.38 (0.67)Breathing 4.19 (1.33) 3.81 (0.75) 3.48 (0.81) 3.48 (0.75) 3.90 (1.00)

(continued)

1554 Journal of Clinical Psychology, December 2001

posttest, breathing participants again scored higher on Strength and Awareness [F(1,40)54.47,p 5 .05]. Interestingly, at Week 5 aftertest, PMR scored higher on Joy [F(1,40)56.15,p 5 .05] and Mental Quiet [F(1,40)5 20.96,p 5 .0005].

Analysis of pretest scores reveals one interesting difference—early in training, atWeek 2, PMR practitioners scored higher on both Disengagement and Physical Relax-ation at pretest [F(1,40)5 10.37,p 5 .003]. No other pairwise comparisons reachedstatistical significance (p $ .05).

Discussion

As predicted by the relaxation response (Benson, 1975) and somatic/specificity hypoth-eses (Davidson & Schwartz, 1976), five weeks of breathing relaxation and PMR gener-ally do not have differential effects on cognitive or physical stress. However, if we broadenour perspective to the full range of relaxation states proposed by ABC relaxation theory(Smith, 1999a), important differences emerge. As hypothesized, PMR appears to evokePhysical Relaxation and Disengagement, whereas breathing evokes feelings of Strengthand Awareness. In addition, PMR appears to evoke Mental Quiet and Joy as a delayedaftereffect (at Week 5, after a break at the end of the study). Major differences emerge at

Table 1(Continued)

R-State Aftertest Group Week 1 Week 5

Sleepiness PMR 5.76 (3.13) 5.43 (2.40)Breathing 4.52 (1.63) 3.86 (1.11)

Disengagement PMR 6.00 (1.76) 7.52 (1.97)Breathing 5.00 (1.87) 4.52 (1.81)

Physical Relaxation PMR 8.52 (1.50) 9.86 (1.80)Breathing 6.30 (2.52) 6.57 (2.20)

Mental Quiet PMR 5.29 (1.82) 6.33 (2.06)Breathing 4.33 (1.71) 3.95 (1.20)

At Ease/Peace PMR 6.81 (1.97) 7.43 (1.89)Breathing 6.14 (1.65) 6.62 (1.56)

Strength and Awareness PMR 6.57 (2.01) 7.10 (2.30)Breathing 6.95 (1.60) 7.71 (2.23)

Joy PMR 6.14 (2.43) 7.29 (1.89)Breathing 5.33 (1.56) 5.71 (1.79)

Love and Thankfulness PMR 5.90 (2.61) 7.05 (2.65)Breathing 6.33 (1.53) 6.71 (1.79)

Prayerfulness PMR 2.43 (1.29) 2.86 (1.49)Breathing 2.19 (1.36) 1.95 (1.16)

Timelessness PMR 2.29 (1.23) 2.86 (1.20)Breathing 2.05 (0.80) 2.10 (0.70)

Physical Stress PMR 3.95 (1.07) 3.61 (0.97)Breathing 4.48 (1.83) 4.10 (1.30)

Worry PMR 1.71 (1.06) 1.52 (0.60)Breathing 2.05 (0.97) 1.86 (0.73)

Negative Emotion PMR 4.24 (1.45) 3.71 (0.72)Breathing 4.43 (1.17) 4.00 (1.10)

*Only Fs for significant repeated measures analyses of covariance reported (see Table 2).

Progressive Muscle Relaxation and Breathing Exercises 1555

Weeks 4 and 5. If replicated, this suggests that relaxation researchers should attempt toassess at least two, and preferably five weeks of training (Smith, 1999b).

Smith (1999b) and others often have commented that PMR may be less intrinsicallyreinforcing than other approaches to relaxation. This may well contribute to high levelsof attrition among practitioners. The present study offers potential insight into the patternof reinforcers associated with PMR. Modest levels of Disengagement and Physical Relax-ation may emerge early in training, and indeed may be anticipated immediately beforetraining (at pretest) during the second week of training. However, the highest levels ofthese two R-States may not appear until Weeks 4 and 5. We found that two stronglyreinforcing R-States, Joy and Mental Quiet, emerge for PMR (and not breathing)—butonly after five weeks of training, and then only after a 3-min break at the end of practice(during which practitioners thought about the day’s activities). Trainers who wish tosensitize practitioners to the benefits of PMR may consider alerting clients to the benefitsof Disengagement and Physical Relaxation early in training. Practitioners may need to bereassured that deeper benefits may take up to four or five weeks, and may appear as anaftereffect. Smith’s (1999b) suggestion that relaxation researchers and trainers assessrelaxation aftereffects may well have some merit.

The overall differential impact of PMR and breathing exercises may have clinicalimplications. Research consistently shows that disturbed individuals already report highlevels of Disengagement (Smith, 2001); however, they do not report high levels of Phys-ical Relaxation. This pattern is characteristic of many forms of psychopathology, includ-ing anxiety, depression, hostility, interpersonal sensitivity, phobic anxiety, and paranoidideation. Perhaps a relaxation technique that evokes Disengagement may be acceptedreadily and applied by individuals who already disengage. Conversely, disturbed individ-uals have low levels of Strength and Awareness; perhaps they would benefit more frombreathing exercises. Research is needed to test these opposing hypotheses.

Overall, the results of this study illustrate the value of considering the ABC approachto relaxation. Clearly, relaxation is more than a global cognitive or somatic response oflowered arousal.

Table 2F Values and Levels of Significance for All Repeated Measures Analyses of Covariance(ANCOVAS) for Relaxation States

Relaxation State F p Group Scoring Higher

Sleepiness .93 (10, 17*) .53Disengagement 16.03 (10, 16) .0005 PMR at Weeks 2, 4, and 5 posttestPhysical Relaxation 17.72 (10, 16) .0005 PMR at Weeks 1, 3, 4, and 5 posttestMental Quiet 8.85 (10, 17) .0005 PMR at Week 5 aftertestMental Relaxation 5.61 (10, 17) .001†Strength and Awareness 10.29 (10, 16) .0005 Breathing at Weeks 1 and 5 posttestJoy 9.79 (10, 17) .0005 PMR at Week 5 aftertestLove and Thankfulness 23.62 (10, 16) .0005†Prayerfulness 1.75 (10, 17) .15Timelessness 1.93 (10, 15) .12Somatic Stress 32.65 (10, 17) .0005†Worry 31.10 (10, 17) .0005†Negative Emotion 18.65 (10, 17) .0005†

*df 5 11, 29; †No significant post-hoc pairwise comparisons between groups; PMR5 Progressive Muscle Relaxation

1556 Journal of Clinical Psychology, December 2001

References

Benson, H. (1975). The relaxation response. New York: Morrow.

Bernstein, D.A., Borkovec, T.D., & Hazlett-Stevens, H. (2000). New directions in progressivemuscle relaxation. Westport, CT: Praeger.

Davidson, R.J., & Schwartz, G.E. (1976). Psychobiology of relaxation and related states: A multi-process theory. In D.I. Mostofsky (Ed.), Behavioral control and the modification of physio-logical activity (pp. 200–233). New York: Free Press.

Jacobson, E. (1929). Progressive relaxation. Chicago: University of Chicago Press.

Lehrer, P.M., & Woolfolk, R.L. (1993). Principles and practice of stress management (2nd ed.).New York: Guilford Press.

Smith, J.C. (1999a). ABC relaxation training: An evidence-based approach. New York, NY: Springer.

Smith, J.C. (1999b). ABC relaxation training: A practical guide for health professionals.New York,NY: Springer.

Smith, J.C. (2001). Advances in ABC relaxation: Applications and inventories. New York, NY:Springer.

Smith, J.C., Amutio, A., Anderson, J.P, & Aria, L.A. (1996). Relaxation: Mapping an unchartedworld. Biofeedback and Self Regulation, 21, 63–90.

Progressive Muscle Relaxation and Breathing Exercises 1557