International Journal of Psychophysiology, 14 (1993) 285-292 0 1993 Elsevier Science Publishers B.V. All rights reserved 0167-8760/93/$06.00

285

INTPSY 446

Short Communication

Psychophysiological profiles in response to various challenges during recovery from acute aerobic exercise

Attila Szabo a, Fraqois P&-onnet a, Ghislain Boudreau a, Lise C6tk a, Lise Gauvin b and Peter Seraganian ’

a Dipartement d’iducation physique, Universite’ de Mont&al, Montrial, Qukbec (Canada), b Department of Exerctie Science, Concordia University, Mont&al, Qukbec (Canada) and ’ Department of Psychology, Concordia University, Montrial,

Qukbec (Canada)

(Accepted 12 October 1992)

Key words: Anxiety; Blood pressure; Epinephrine; Exercise; Heart rate; Mood; Norepinephrine; (Human)

Cardiovascular and sympathetic profiles in response to a series of physical and mental challenges were examined during

recovery from an acute bout of aerobic exercise performed at 60% Vo2,,,ax for 30 min. 9 healthy men were tested on two occasions, once under an experimental (exercise) and once under a control (video watching) condition, in a counter-balanced order, one week

apart. Although no differences in blood pressure were found in the two conditions, heart rate and plasma catecholamine

concentrations were higher in the exercise than in the control session. These findings were partly attributed to elevated

physiological levels ‘carried over’ from exercise. State anxiety and anger-hostility, however, were lower in the post-experimental

period than in the pre-experimental period. The results are discussed in terms of their relevance to exercise and stress

psychophysiology.

Following an acute bout of aerobic exercise, lower blood pressure (BP) levels may be observed in normotensive, as well as hypertensive subjects (Bennett et al., 1984; Boone et al., 1992; Floras et al., 1986; Hannum and Kasch, 1981; Kaufman et al., 1987; Paulev et al., 1984; Wilcox et al., 1982). The exact mechanism for postexercise hypoten- sion is still unknown. Floras et al. (1986) have demonstrated that the hypotensive effects of moderate aerobic exercise, in borderline hyper- tensives, may be related to a decrease in periph- eral sympathetic nerve activity. Partial support for this mechanism was contributed by Ptronnet et al. (19891, who examined the effects of a 2-h

Correspondence to: F. Peronnet, Departement d’education physique, Universitd de Montreal, C.P. 6128, succ. A,

Montreal, Quebec, Canada, H3C 357.

bout of moderate intensity (50% Vo,,,,> cycling on heart rate (HR), BP and plasma cate- cholamine (CA) dynamics in normotensives dur- ing exposure to a series of physical and psycho- logical challenges in the immediate postexercise recovery period. Plasma epinephrine (EPI) con- centration in the antecubital vein was nearly 50% lower at postexercise rest, during hand-grip exer- cise, and during the Stroop color word task fol- lowing exercise, than following a 2-h video-watch- ing, control, session. However, no differences in plasma norepinephrine (NE) concentration, HR and BP were observed between the exercise and video session.

To further clarify these processes, the first objective of the present study was to reexamine the effects of a shorter (i.e., 25% of that em- ployed by Peronnet et al., 1989) bout of exercise on HR, BP and plasma CA concentrations in

286

response to challenging physical and psychologi- cal tasks during exercise recovery period. One major modification, in comparison to the study by Ptronnet et al. (1989), the reduction of the exer- cise period from 2 h to 30 min, was implemented to examine whether decreases in sympathetic ac- tivity after shorter duration exercise may also be observed. The adopted design was a partial repli- cation of the study by Peronnet et al. (1989).

Furthermore, psychological benefits of aerobic exercise are extensively publicized. In a fre- quently cited literature review, Folkins and Sime (1981) presented evidence for the improvement of affective states, including mood and anxiety, following exercise training. The immediate psy- chological impacts of an acute bout of exercise have also been extensively studied. While varia- tions due to exercise intensity, modality (Berger and Owen 1987; 1988) and subject characteristics may be found, the general consensus is that, after an acute bout of exercise, improved mood states (North et al., 1990) along with reduced state anxiety (Petruzello et al., 1991) may be observed. For example, lower postexercise state anxiety has been reported in both runners (e.g., Boutcher and Landers, 19881 and swimmers (e.g., Berger and Owen, 1987). Bahrke and Morgan (19781, however, have shown that a 20-min bout of aero- bic exercise, meditation and rest were equally effective in reducing state anxiety. Positive changes in affective states after an acute bout of exercise, which may persist from 2 to 5 h post-ex- ercise (Morgan, 19851, were also reported (Ewing et al., 1984; Lichtman and Poser, 1983; Markoff et al., 1982).

A second aim of the present study was there- fore to examine state anxiety along with affective (mood) states and their relationship to cardiovas- cular and sympathetic responses, upon comple- tion of an acute bout of exercise followed by exposure to a sequence of different stressors. It was hypothesized that consecutive exposure to a series of challenges would result in increased levels of post-experimental anxiety and decre- ments in affective states, but that a previous bout of aerobic exercise would buffer such effects.

Data are presented for 9 healthy males who consented to participate in the study. Their age

was 31.6 + 3.2 years (mean kS.E.1, their weight was 74.2 k 3.0 kg and their height was 178.4 k 1.4 cm. Subjects’ resting HR, as determined during an initial screening session, was 77.1 _+ 3.1 beats per minute (bpm), systolic blood pressure was 126.1 k 4.6 mmHg, and diastolic blood pressure was 76.9 k 2.6 mmHg. Subjects’ estimated 1/02,max, as determined on the basis of the modified As- trand-Rhyming method (Siconolfi et al., 1982) by using a Monark ergometer, was 39.9 + 3.3 ml/kg per min, and their maximal voluntary isometric force of prehension was 37.8 k 2.6 kg as mea- sured with a Lafayette hand-grip dynamometer. Subjects received $60.00 Can. for taking part in the experiment, which involved three morning visits (one screening and two experimental ses- sions) to the laboratory between 8 a.m. and 11 a.m. Participants were instructed to have a light breakfast and to refrain from exercising and drinking caffeinated beverages before each test session.

Testing was performed in an electrically shielded room (3 x 3 x 3.5 m, temperature of 25°C and 50% humidity (Spectrashield). The ex- perimental and the video sessions consisted of an identical sequence of events that included: (11, rest for 10 min (following the insertion of the needle for blood sampling); (2), exercise (or video) for 30 min; (31, supine rest for 10 min; (41, stand- ing for 5 min; (51, sitting for 5 min; (61, isometric hand-grip exercise at 25% maximal voluntary force for 3 min; (7), mental arithmetic for 3 min that consisted of a series of additions and sub- tractions (e.g., 13 + 5 - 11) interposed with serial subtractions (e.g., to subtract continuously 7 from 101) for 30 s; (8), Stroop color word task for 3 min @troop, 1935) which involved the simultane- ous auditory and visual presentation (Fran- kenhaeuser et al., 1968) of colour words, such as ‘blue’, printed in conflicting colours, for example in red (the subjects’ task was to ignore the actual word itself and report only the colour in which it was presented visually) and (91, cycling at 60% maximal aerobic power for 5 min. In the last 30 s of each period HR and BP were recorded by using a Vita-Stat Electronic Sphygmomanometer (model 9000) and 2-ml blood samples were with- drawn from an antecubital vein (with a single

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venipuncture), using an 18 G butterfly catheter. Plasma EPI and NE concentrations were meas- ured by using the radio-enzymatic method devel- oped by Peuler and Johnson (1977). In our labo- ratory, the sensitivity of this method is between 15 and 25 pg/ml and the reproducibility is be- tween 8 and 13% (Ptronnet et al., 1986).

The only difference between the experimental and the control session was that in the former subjects were asked to cycle on a Monark station- ary bicycle for 30 min at 60% l/oZ,,,ax while in the latter they watched a video tape of geographical sceneries for 30 min. The two sessions were pre- sented in a counter-balanced order. Before and after each session, subjects were asked to answer the Spielberger State and Trait Anxiety Inventory (STAI; Spielberger et al., 1979) and the Profile of Mood States (POMS; McNair et al., 1981) ques- tionnaires.

Heart rate, BP and plasma CA concentrations were analyzed using a two (2 - condition: exer- cise, video) by nine (9 - period: control, treat- ment (exercising or video watching), supine rest, standing, sitting, hand-grip exercise, mental arith- metic, Stroop task and dynamic exercise) re- peated measures ANOVA. For within-session comparison purposes, the initially recorded ‘con- trol’ values were adopted as baseline measures. Psychological data were analyzed using a two (2 - condition: exercise, video) by two (2 - period: pre, post) repeated measures ANOVA. All analy- ses were performed by using the ‘Systat’ statisti- cal software package (Wilkinson, 1989). The Greenhouse-Geisser probability levels were a- dopted in conjunction with the repeated meas- ures ANOVAs.

The alpha probability level was set to 0.05 for all tests.

Analyses of the HR data revealed a significant condition main effect (F&S) = 26.7, P < 0.0011, a period main effect (F(8,64) = 104.0, G-G P < 0.001) and a significant condition by period inter- action (F(8,64) = 41.1, G-G P < 0.001). Further analyses of the interaction indicated that in com- parison to control (baseline) values, significantly higher HRs were observed in all periods during exercise session, but during video session HR differences from baseline occurred only in the

170

Sampling Period

Fig. 1. Heart rate during the various experimental periods.

Significant statistical differences between exercise (*) and

control (video) (0) session were found in: treatment (exercise

vs. video) (P < 0.001). supine position (P < 0.001). sitting

(P < 0.01) and mental arithmetic (P < 0.01).

supine position (when HR was lower than the baseline; F(l,S) = 9.1, P < 0.05) and during the last 5 min acute exercise @X1,8) = 327.4, P < 0.001). Significantly greater HR responses were found during the exercise recovery period, in comparison to the video session, in supine posi- tion (F(l,Sl = 43.18, P < O.OOl), sitting position (F(l,S) = 15.9, P < 0.005) and during mental arithmetic (F(l,S) = 12.28, P < 0.01). In standing position and hand-grip exercise the differences approached (F(l,S) = 5.01, P < 0.06 and F(l,S) = 3.81, P < 0.091, but did not reach significance. There were no differences during the Stroop task and the last 5-min dynamic exercise under the two conditions (Fig. 1).

These findings parallel the results obtained by Peronnet et al. (19891, and they reveal that an upward shift, or an increase in HR, that was a result of the acute exercise bout, was ‘carried over’ in the postexercise period. This ‘carry-over’ effect is supported by both between and within session data analyses. The former indicates that in the exercise session HR was, in general, higher in all testing periods than in the video session.

288

The latter reveals, that in comparison to initial (control) baseline, HR was higher in all periods in the exercise session, but in the video session only the last 5 min of dynamic exercise could increase HR to above baseline levels (Fig. 1). In contrast to the results of Peronnet et al. (19891, HR was not higher in response to the last 5 min bout of exercise in the exercise than in the video session. The reason for this discrepancy is un- clear, however, it may be related to differences in exercise duration.

The general finding of greater HR response to various challenges in exercise recovery period was interpreted as a possible slight impairment in ventricular performance following prolonged ex- ercise in the Peronnet et al. (1989) study. While this mechanism cannot be ruled out, in the pre- sent study, where exercise duration was 25% of that used by Peronnet et al. (19891, the likelihood of ventricular impairment was reduced. However, sustained greater HR in postexercise period may also be related to increased body temperature and increased oxygen consumption in the imme- diate postexercise period (Brooks and Fahey, 1984).

For systolic BP the 2 X 9 repeated measures ANOVA yielded no significant condition main effect, but a significant period main effect (F(8,64) = 20.5, G-G P < 0.001) and a significant condition by period interaction (F(8,64) = 7.9, G-G P < 0.001). Follow-up analyses revealed that during the video session, SBP taken in the sitting position was lower than the initial baseline mea- sure (F(l,B = 6.19, P < 0.04), but higher during the last 5 min of dynamic exercise (F(l,B) = 19.7, P < 0.01). In the experimental session, SBP was higher, than the baseline measure, only during the 30 min (F(l,B) = 77, P < 0.001) and the 5 min (F(1,8) = 7.7, P < 0.02) exercise. This interaction, thus, was simply due to treatment differences (exercise vs. video) in the two conditions (F(l,B) = 25.6, P < 0.001). Repeated measures ANOVA on diastolic BP data yielded no significant main effects or interaction (Fig. 2).

These findings replicate the results obtained by Peronnet et al. (19891, indicating that BP during physical, orthostatic and mental challenge is not modified by a previous bout of aerobic

160 -

f E 140 -

5

z 2 120 -

: h ; 100 -

s q

60 -

SOI ’ ’ ’ ’ ’ ’ ’ ’ ’

Sampling Period

Fig. 2. Blood pressure during the various experimental peri- ods. No statistical differences were found between the exer-

cise (0, n ) and control CO, 0) session, except in SBP response

to exercise treatment (P < 0.001).

exercise in normotensive males. During the video session, SBP recorded in the sitting position, was lower than the baseline recorded in the same physical position. This finding may be related to pre-experimental anticipation effects. However, it may be also related to potential relaxing effects of the 30 min video watching, which involved sitting in a comfortable armchair and was fol- lowed by a 10 min rest period in supine position.

The analyses of NE concentrations revealed a significant condition main effect (F(1,6) = 28.9, P < 0.0021, a significant period main effect (F(8,48) = 19.8, G-G P < 0.001) and a significant condition by period interaction (F(8,48) = 14.4, G-G P < 0.002). In comparison to initial (control) values, plasma NE concentrations were lower in supine position (F(1,6) = 9.7, P < 0.05) and higher in standing position (F(1,6) = 185.8, P < 0.001) during both episodes of mental stress (F(1,6) = 11.2, P < 0.05; F&6) = 9.7, P < 0.01, respectively) and during the 5 min dynamic exer- cise (&X1,6) = 16.1, P < 0.01) in the video session. In the exercise condition, however, higher than initial (control) NE concentrations were found only during the 30 min (F(1,6) = 18.8, P < 0.01)

and the 5 min (F(1,6) = 58.3, P < 0.001) exercise and during the standing position @(1,6) = 12.5, P < 0.01). It should be noted that, unlike with SBP, there were no significant differences be- tween control plasma NE concentration recorded as baseline, and NE concentration measured in the sitting position, neither during the video nor during the exercise session. Further anaiy~ indi- cated that pIasma NE concentration were higher in aii periods @ignificant effects are shown in Fii. 3) of the experimental session kxcept the 5 mhr exercise) than in the video control session (Pig. 3).

AnaIyses of the plasma EPI dynamb reveaied a significant condition main effect W(1,6) = 50.8, P< O.OOl), a significant period main effect (1;(8,48) k 75, G-G P < O.oa3) and a signi&nt condition by period interaction W(8,4S)- 7.5, G-G P < 0.002). Further anaiyses of these fhrd- ings reveakd that during the video session plasma EPI concentrations increased above baseline vaI- ues in the standing position (F(1,6) F 7.7, P <

1200 )I

1000 -

C

F 800 - g

4 2 600 -

8 5 400 - ‘0 2

200 -

$mmpllng Pwlod

Fig 3. Plasm norepinepbrine levels awing the various cqsr- imentalperkKk.mlediffmmsbctwccn cxmAc MI and vidmse&m(0)wcresignificmtinallimtmaqexceptin thefinai5minofdynRmiCcyciiqtcmriac: control (P < Om, WeatQmlt kyc4ing w. video) w < O.OlX supine rest (P < 0.01x standing w < o.OsI# sittiug (P c 0.01x ha&pip (P c O.OlA melltal al%mctk (P<O.OOl) ad stroop tack (P<O.Ol).

Sampling Pukd

Fig. 4. Plasma epinephrinc levels durinp the various experi- mental periods. The diEelwMx# bctwcul excrcisc (01 and videu acssion (o)wcre stati&auy sigoi6cant in the fokving periods: treatment (W vs. vidd (P < O.atl~, supine Est (P < 0.011, silt& (P < aOl), hand-grip (P < 0.05) and during

the 5 mill dynamic uen5se (P < 0.05).

0.05), during hand-grip exercise (F(1,6) = 8.8, P c 0.0!5), durhrg mentai arithmetic M1,6) = 16.5, P < 0.00, during the Stroop task Ml,61 = 19.0, P c 0.01) and during the 5 mhr exercise (F(1,6) = 13.9, P< 0.01). The actual video watching re- sulted in lower than baseline kontrol) plasma EPI concentration (F(l,d) = 12.4, P < 0.01). Simi- lar to pIa8ma NE, higher than control plasma EPI concentrations in the experhnental session were seen only during the 30 mhr (F(1,6) = 19.5, P c 0.01) and the 5 ruin exercise (F(1,6) = 8.3, P c O&i), and unlike NE, plasma EPI concentrations were significantiy greater during the Stroop task (F(1,6) - 26.7, P < 0.01) in comparison to base- Iine IeveIs. Further analyses of the interaction reveakd that plaxna EPI concentrations in the exercise session were greater than in the video 8essicm in the foIIowing periods: treatment (ex- ercise vs. video; (F(1,6) = 43.3, P < O.OOl), supine position (F(1,6) - 14.9, P < 0.00, sitkg (F(1,6) - 19.8, P < O.Ol), hand-grip exercise (F(l,6) = 7.7, P ~0.05) and the 5 min dynamic exercise (F(1,6) = 9.4, P < 0.05) (Pig. 41.

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Higher plasma NE concentrations during exer- cise recovery than following control, video watch- ing, do not replicate the results of Peronnet et al. (1989). These findings reveal that plasma NE concentrations in response to a series of chal- lenges encountered during recovery from a 30 min bout of exercise are higher than NE concen- trations in response to the same series of chal- lenges following a 30 min neutral video watching session. Paralleling the results obtained with plasma NE concentrations, and in contrast to the

results of Peronnet et al. (19891, plasma EPI concentrations were also higher in the exercise recovery than control period during most stimuli, except during standing and mental challenge, in which periods no significant differences were re- vealed. The discrepancy between the present and the study by Peronnet et al. (1989) may require further clarification, but it may be related to differences in the exercise duration in the two studies.

TABLE I

State and Trait Anxiety (STAI) and Profile of Mood States (POMS) scores before and after an exercise session and before and after a video session

The values represent means f S.E. (n = 9)

Exercise

Pre Post

Video

Pre Post

STAI

State Anxiety

Raw score

T-score

Trait Anxiety

Raw score

T-score

37.9 (3.8) 34.3 (3.1) 41.1 (2.1) 38.9 (2.3)

51.1(4.0) 48.0 (3.5) 55.7 (2.0) 53.4 (2.2)

42.8 (2.6) 43.2 (3.3) 44.0 (3.3) 44.9 (4.1)

55.7 (2.3) 55.7 (2.7) 56.2 (3.0) 57.1 (3.8)

POMS Tension-Anxiety

Raw score

T-score

Depression/Dejection Raw score

T-score

Anger-Hostility Raw score T-score

Vigour Raw score

T score

Fatigue Raw score T-score

Confusion Raw score

T-score

4.6 (1.8) 3.6 (2.0) 7.2 (2.5) 6.7 (2.3)

37.6 (2.6) 33.9 (4.1) 40.2 (4.0) 39.3 (3.8)

7.7 (3.7) 7.1 (4.4) 14.3 (5.0) 13.6 (5.7)

44.2 (3.4) 43.7 (4.0) 50.1 (4.5) 49.3 (5.2)

7.7 (2.7) 4.1(1.9) 9.4 (3.5) 7.1 (3.1) 47.3 (3.7) 43.3 (2.4) 49.6 (4.6) 46.6 (4.1)

15.2 (1.5) 14.8 (1.3) 12.7 (0.8) 10.7 (1.6)

49.6 (2.4) 48.8 (2.1) 45.3 (1.2) 4.23 (2.5)

5.3 (1.3) 7.7 (1.9) 9.7 (2.2) 9.0 (2.8) 41.9 (2.0) 45.6 (2.9) 48.7 (3.4) 47.7 (4.3)

1.0 (1.0) 2.3 (1.4) 3.4 (1.8) 4.2 (1.9)

29.9 (2.7) 33.0 (3.1) 34.3 (4.1) 35.9 (4.4)

291

To account for possible uniqueness of the sub- jects * and to allow comparison with population norms, the effects of exposure to a series of stressors on anxiety and affect after exercise and video control condition, were analyzed using both the raw and the T-scores of the STAI. The two scores yielded the same results, unless otherwise mentioned. A period main effect @X1,8) = 5.23, P < 0.05) indicated that state anxiety was lower in post- than pre-sessions, regardless of treatment conditions (Table I). However, if these data were analyzed in terms of T-scores (norms), they only approached statistical significance (F(1,8) = 4.23, P < 0.07). As expected, no significant differences were found in trait anxiety neither between exer- cise and video conditions, nor between pre- and post-scores (Table I).

The POMS is subdivided into six subscales and they were analyzed accordingly, using two by two repeated measures ANOVAs. A significant de- crease in anger-hostility after both, exercise and video, sessions was revealed by an overall period main effect @X1,8) = 5.13, P < 0.05).

Both lower state-anxiety and anger-hostility in the post- than pre-experimental period may be related to a methodological concern. In pre-ex- perimental conditions subjects may have been more anxious because of the approaching discom- forts associated with the experimental protocol, such as the insertion of the catheter in the fore- arm for blood sampling. This anxiety may have been decreased in the post-experimental period because the subjects had completed all the re- quirements involved in the experimental protocol. The subjective knowledge of no longer being faced with (instead of approaching) discomforts may have had an impact on anxiety and/or anger/ hostility profile of the subjects. In fact, these expectancy effects may have been more powerful than any treatment effects.

* The psychological profile of the subjects who are willing to volunteer for studies that may involve painful procedures,

such as blood sampling, and who also report a healthy, physi- cally active lifestyle, may or may not be comparable with

population norms whose development did not involve screen-

ing for similar characteristics.

A condition main effect on the vigour scale (F&8) = 5.08, P < 0.05) indicated higher scores during the exercise than the video session, which may reveal an anticipatory effect associated with exercising. Initially greater plasma NE (baseline) concentrations during the exercise session seem to parallel these findings and may be associated with exercise anticipation. However, subjects also knew that during video watching they would be sitting for 30 min, which may be related to less vigorous, or even lethargic states. Thus, the higher vigour observed in the exercise session could re- flect either an anticipation of the arousal-induc- ing properties of exercise or the sedentary nature of the video watching activity. The role of these two processes should be tested experimentally in the future.

No significant differences were found on the tension-anxiety, depression-dejection, fatigue and confusion scales. A total mood disturbance score (TMD) was derived from the addition of all sub- scales minus the vigour subscale as suggested by McNair et al. (1981). The analyses of these in- dices also yielded non-significant effects.

No evidence was found for the contention that exposure to a series of physical and mental chal- lenges in laboratory settings result in different anxiety levels and affective states between an exercise-recovery and video control session. These findings suggest that 30 min of moderate aerobic exercise, followed by a series of challenges, does not influence psychological states any more or any less than 30 min of video watching followed by an identical series of challenges. Therefore, the hypothesized ‘buffering’ capacity of a single bout of aerobic exercise could not be demon- strated in the present study.

This study was supported in part by grants from the FCAR, NSERC and Canadian Fitness and Lifestyle Research Institute to Dr. Franqois Peronnet. Gratitude is extended to the fonds FCAR for supporting A. Szabo.

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