Influence of psychogenic factors during a prolonged maximal run.

Beaudoin, Christina M. ; Crews, Debra J. ; Morgan, Don W. 等

Several researchers (Benson, Dryer, & Hartley, 1978; Hatfield, Spalding, Mahon, Slater, Brody, & Vaccaro, 1992; Morgan, 1985; Williams, Krahenbuhl, & Morgan, 1991) have demonstrated that psychogenic factors (e.g., hypnosis, meditation, mental strategies, mood) can influence cardiorespiratory responses to an exercise stimulus. One area that has received considerable attention in sport psychology is the use of cognitive strategies or the manipulation of attentional focus (e.g., association, dissociation) to improve performance or exercise efficiency.

An associative attentional focus concentrates one's awareness on bodily states, self-perceptions, and pacing or rhythm related to an activity. Conversely, a dissociative attentional focus or distraction diverts attention away from bodily self-awareness and self-perceptions and towards external stimuli or factors not related to an activity (e.g., words of a song, other people exercising). Studies have found conflicting results as to whether association or dissociation is a more effective strategy for improving performance (Fillingim & Fine, 1986; Goode & Roth, 1993; Morgan & Pollock, 1977; Pennebaker & Lightner, 1980; Weinberg, Jackson, & Gould, 1984). Conflicting results may be due to varying activity modes, differences in individual fitness levels, and exercise experience. Crews (1992) summarized literature examining the relationship between cognitive strategies and exercise performance and concluded that experienced performers benefit from associative strategies while less experienced performers benefit from dissociative strategies.

It is already known that elite male and female distance runners possess unique psychological characteristics (e.g., less anxiety, less depression, use of associative strategies) (Morgan, O'Connor, Sparling, & Pate; 1987; Morgan & Pollock, 1977) that may influence their [TABULAR DATA FOR TABLE 1 OMITTED] running performance. Elite and well-trained runners may also possess similar physiological attributes (e.g. aerobic capacity); thus for elite and well-trained athletes possessing similar physiological attributes, psychological factors may influence performance to a greater extent than physiological factors. Therefore, the purpose of this study was to examine the influence of psychological factors (i.e., thoughts, feelings, and perceptions of exertion) upon physiological responses during a prolonged maximal run at 90% [Mathematical Expression Omitted] max in well-trained runners. Physiologically, well-trained runners should be capable of completing a run of this intensity and duration (Daniels & Gilbert, 1979; Leger, Mercier, & Gauvin, 1986). Psychologic responses to a run of this intensity and duration have not yet been examined.

Methods and Procedures

Participants

Eleven male distance runners volunteered to participate in the study. Physical characteristics, running experience, and 10-km performance times of the participants are displayed in Table 1. based upon training experience, [Mathematical Expression Omitted] max, and performance times, these runners were classified as well-trained, with the physiological capacity to complete a 30-min run at 90% [Mathematical Expression Omitted] max.

An Institutional Review Board for the protection and welfare of human subjects approved the experimental protocol and participants were acquainted with all aspects of the study before consenting to participate. After written informed consent was obtained, participants completed a series of sessions. Procedures employed during each session are described in the following section.

Session 1 (Maximal Oxygen Uptake Test)

In the first session, purposes and procedures of the study were explained to the subject and written informed consent obtained. Maximal oxygen uptake was determined using a modified version of the Bransford and Howley (1977) protocol. Subjects completed a 1.5 min level treadmill warm-up at 230 m [center dot] [min.sup.-1] followed by 1.5 min at 242 m [center dot] [min.sup.-1] at 0% grade. Treadmill velocity remained at 242 m [center dot] [min.sup.-1] for the remainder of the test and treadmill elevation was increased 2.5% every 2 min until the runner reached volitional exhaustion. Heart rate was monitored continuously with a 3-lead ECG and expired air was collected in meteorological balloons for 1-min periods after a heart rate of 160 b [center dot] [min.sup.-1] was reached. Gas collections continued until the graded exercise test was terminated.

Meteorological balloons were analyzed for oxygen ([O.sub.2]) and carbon dioxide (C[O.sub.2]) concentrations using Ametek Applied Electrochemistry [O.sub.2](S-3A/I) and C[O.sub.2] (CD-3A) analyzers. Analyzers were calibrated before and after each run using gases of known concentrations. Gas volumes were determined by evacuating expired air samples from the meteorological balloons into a Rayfield gas meter calibrated against a Collins Tissot. Oxygen consumption was computed using standard equations for open-circuit collection methods. Standard leveling criteria (Taylor, Buskirk, & Henschel, 1955) were used to determine attainment of [Mathematical Expression Omitted] max. In cases in which a plateau in [Mathematical Expression Omitted] was not achieved, the highest [Mathematical Expression Omitted] obtained was designated as [Mathematical Expression Omitted] max.

Sessions 2 and 3

Two days after the maximal oxygen uptake test, participants completed two sessions, each consisting of level treadmill runs at three submaximal running speeds to determine the aerobic demand of running (e.g., running economy). Each session was performed on a different day and sessions were one day apart.

During each session, participants completed economy rims at 241.2 m [center dot] [min.sup.-1], 268.0 m [center dot] [min.sup.-1], and 295.0 m [center dot] [min.sup.-1]. After a self-selected warm-up, participants completed a 3-min warm-up at 241.2 m. min followed by the 6-min economy run. Five-min rest periods separated each 6-min economy run.

Session 4

Using data collected in Sessions 1, 2, and 3, the running speed associated with a relative intensity of 90% [Mathematical Expression Omitted] max was predicted using linear regression. Following a short warmup, participants completed 3, 10-min level treadmill runs at 90% [Mathematical Expression Omitted] max and expired air samples were collected from min 6-8. If the [Mathematical Expression Omitted] obtained was markedly different from the desired 90% [Mathematical Expression Omitted] max, changes in treadmill belt velocity were made to achieve the desired exercise intensity. Runners were allowed a 10-min rest between each bout of exercise.

Sessions 5-7

Two days following session 4, participants completed a 30-min level treadmill run at 70% [Mathematical Expression Omitted] max. Air samples were collected during min 13-15 and 28-30. Participants completed this 30-min run for 3 consecutive days. The purpose of these sessions was to simulate a pre-race taper. No outside running was performed during this phase of the study.

Sessions 8 and 9

On the two consecutive days following the 30-min run at 70% [Mathematical Expression Omitted] max runners completed 10-min level treadmill runs at 90% [Mathematical Expression Omitted] max. Expired air was sampled from min 6-8. Data collected in these sessions, while not germane to the purpose of the current investigation, were used to determine the short-term effects of prolonged maximal running at 90% [Mathematical Expression Omitted] max on running economy and running mechanics. Data collected during sessions 8 and 9 was compared to data collected during sessions completed after the fatigue run. These sessions also familiarized runners with the pace they would be running during the 30-min run at 90% [Mathematical Expression Omitted] max.

Session 10 (Fatigue Run)

Three days after completing the 10-min run at 90% [Mathematical Expression Omitted] max, runners completed a 30-min level treadmill run at 90% [Mathematical Expression Omitted] max. Expired air was sampled for 1-min after min 9 of the run using standard open-circuit methods. A second air sample was collected after min 20, if runners allowed.

Rating of Perceived Exertion (RPE) (Borg, 1985) and Feeling Scale (Hardy & Rejeski, 1989) responses were collected during rains 9, 19, and 30 (or immediately before stopping). The RPE scale requires participants to rate the total amount of exertion they feel during a particular work bout. The scale ranges from 6 to 20 with verbal anchors at each odd integer (e.g., 7 = very, very light; 19 = very, very bard). The Feeling Scale is used to measure affect during exercise. The 11-item scale ranges from +5 to -5 with verbal anchors at 0 and odd integers (e.g., +5 = very good; -5 = very bad). Participants were asked to verbally report their thoughts and feelings during rains 5, 9, 14, 19, and 30 (or immediately before stopping). After completing the run, runners completed a postrun structured interview. The postrun interview contained questions related to the attentional focus of the runner during the run.

Results

Physiological Data

All subjects completed a total of 30 min of running at 90% [Mathematical Expression Omitted] max, however, only 4 subjects (finishers) completed the 30-min run without stopping. The remaining runners (nonfinishers) ran an average of 21.75 + 3.19 min (M [+ or -] SD) before stopping. Nonfinishers were allotted 1 (n = 5) or 2 (n = 1) rest periods in order to complete a total of 30-min at 90% [Mathematical Expression Omitted] max. Physiological data collected during the run are presented in Table 2. Results of independent t-tests revealed no significant differences in [Mathematical Expression Omitted] max, [Mathematical Expression Omitted] (ml[center dot][kg.sup.-1][center dot][min.sup.-1]), % [Mathematical Expression Omitted] max, or [Mathematical Expression Omitted], during the run between finishers and nonfinishers. Results revealed that heart rate for finishers (M [+ or -] SD = 173.25 + 9.50 b[center dot][min.sup.-1]) was significantly lower than nonfinishers (M [+ or -] SD = 188.00 + 4.64 b [center dot] [min.sup.-1], t(7) = 3.08, p [less than] .05) at 9 min.

Independent t-tests conducted on economy runs(241.2 m [center dot] [min.sup.-1], 268.0 m [center dot] [min.sup.-1], 295.0 m [center dot] [min.sup.-1]) revealed no significant differences in running economy between finishers and nonfinishers.

[TABULAR DATA FOR TABLE 2 OMITTED]

[TABULAR DATA FOR TABLE 3 OMITTED]

Psychological Data

Psychological data collected during the run are presented in Table 3. Results of independent t-tests revealed that RPE at 19 min was significantly higher for nonfinishers than finishers, t(9) = -3.48, p [less than] .01. FS responses were also more negative for nonfinishers than Finishers at 19 min, t(8) = 3.33, p [less than] 01.

Runners were asked to verbally report their thoughts and feelings at 5, 9, 14, 19, and 30 mins (or immediately before stopping). Runners' responses were recorded and later analyzed by two authors. Responses revealed that finishers generally reported positive thoughts and feelings such as being confident, in control, smooth, and relaxed. Compared to finishers, nonfinishers reported more negative thoughts and feelings and expressed doubt and concern about their ability to complete the 30-min run.

Postrun structured interviews were analyzed and revealed that Finishers reported an internal rather than external focus and focused more on their body and rhythm rather than cognitions unrelated to the run.

Experiential Data

Independent t-tests were conducted to examine potential differences in running experience (yrs), best 10-km time, and recent 10-km time between finishers and nonfinishers. Results revealed no significant differences in experiential variables between finishers and nonfinishers.

Discussion

A 30-min run at 90% maximal aerobic capacity represents a difficult and challenging task for well-trained runners because they rarely run at this pace continuously for this length of time. The purpose of this study therefore, was to examine the influence of psychological and physiological response to a run of this intensity and duration. It was thought that psychological factors (e.g., thoughts, feelings, attentional focus) might influence performance during a run of this intensity and duration among a group of well-trained runners.

Of the 11 runners participating in the study, only 4 runners were able to complete the 30-min run at 90% [Mathematical Expression Omitted] without stopping. Results of the study revealed no significant differences in [Mathematical Expression Omitted], [Mathematical Expression Omitted], ventilation, or respiratory exchange ratios between finishers and nonfinishers during the run. Heart rate for finishers was significantly lower at 9 rain than nonfinishers. Because [Mathematical Expression Omitted] was similar for finishers and nonfinishers, the additional cardiac activity (i.e, heart rate) of nonfinishers may have indicated that they perceived the task as more psychologically challenging than finishers. This finding is consistent with studies reporting associations between mental stress and augmented sympathetic activity (Sims & Carroll, 1990; Turner, Carroll, Hanson, & Sims, 1988). Experientially, finishers and nonfinishers were similar in terms of years of experience, and 10-km performance times. Thus, although physiologically and experientially these runners appeared to have the capacity to complete the 30-min run, they did not all do so; therefore, psychological factors may have influenced running performance.

Psychologically, RPE and FS responses differed for finishers and nonfinishers at 19 min. Results revealed that RPE was greater and FS responses more negative for nonfinishers than finishers. Finishers also reported more positive thoughts and feelings than nonfinishers during the run. Nonfinishers reported more negative thoughts and feelings and expressed doubt and concern about completing the 30-min run. Thus, from responses collected during the run, nonfinishers appeared to have been employing more negative self-talk and experiencing more negative thoughts and feelings and greater perceptions of exertion than finishers. Psychologically the nonfinishers appeared to have been stressed by the exercise task to a greater extent than finishers were. The association between negative affect and impaired performance is consistent with research reported by Jones and Hardy (1990).

In terms of psychological strategies employed during the run, postrun interviews revealed that finishers reported an internal focus of bodily awareness and monitoring of rhythm, thus an associative attentional focus. Nonfinishers reported an external focus (e.g., words of a song, lab assistant's actions) and focused on cognitions unrelated to the run, thus a dissociative attentional focus. Thus, the attentional focus as well as thoughts and feelings of the runner may have influenced running performance. The results of the present study are consistent with results of previous studies examining associations between cognitive techniques and performance (Crews, 1992; Morgan & Pollock, 1977); that is well-trained, experienced, elite performers benefit from an associative attentional focus. Practical implications from this particular study suggest that well-trained runners may benefit from an internal associative attentional focus for races that may be comparable to the task employed in this study (i.e., 10-km).

In conclusion, results of the study suggest that psychological factors influence running performance. Although runners in the present study were physiologically capable of completing a 30-min run at 90% [Mathematical Expression Omitted], it appears that there are psychological factors in addition to physiological factors that influence running performance. Although all runners appeared to have been equally stressed by the workload physically, future studies might examine muscle glycogen concentrations or blood lactates as differences in these parameters might provide further insight to physiological responses to a run of this intensity and duration. Additionally, future studies may examine attentional styles or thought/feeling patterns during actual performances (e.g., 10-km) as well as examine differences between experienced and less experienced runners. Further systematic investigations examining associations between psychological factors and physiological responses to exercise are warranted as there may be implications for enhancing running performance.

References

Benson, H., Dryer, B.A., & Hartley, H.H. (1978). Decreased [Mathematical Expression Omitted] consumption during exercise with elicitation of the relaxation response. Journal of Human Stress, 4, 38-42.

Borg, G. (1985). An introduction to Borg's RPE scale. Ithaca, NY: Mouvement Press.

Bransford, D.R., & Howley, E.T. (1977). Oxygen cost of running in trained and untrained men and women. Medicine and Science in Sports and Exercise, 9, 41-44.

Crews, D.J. (1992). Psychological state and running economy. Medicine and Science in Sports and Exercise, 24, 475-482.

Daniels, J., & Gilbert, J. (1979). Oxygen power: Performance tables for distance runners. Tempe, AZ: Daniels, & Gilbert, POB 26287, Tempe, AZ 85282.

Fillingim, R.B., & Fine, M.A. (1986). The effects of internal versus external information processing on symptom perception in an exercise setting. Health Psychology, 8, 115-127.

Goode, K.T., & Roth, D.L. (1993). Factor analysis of cognitions during running: Association with mood change. Journal of Sport and Exercise Psychology, 15, 375-389.

Hardy, C.J., & Rejeski, W.J. (1989). Not what, but how one feels: The measurement of affect during exercise. Journal of Sport and Exercise Psychology, 11, 304-317.

Hatfield, B.D., Spalding, T.W., Mahon, A.D., Slater, B.A., Brody, E.B., & Vaccaro, P. (1992). The effect of psychological strategies upon cardiorespiratory and muscular activity during treadmill running. Medicine and Science in Sports and Exercise, 24, 218-225.

Jones, J.G., & Hardy, L. (1990). Stress and performance in sport. Chichester, UK: Wiley.

Leger, L., Mercier, D, & Gauvin, L. (1986). The relationship between [Mathematical Expression Omitted] and running performance time. In D.M. Landers (Ed.) The 1984 Olympic Scientific Congress proceedings, Vol. 13, Sport and elite performers (pp. 113-119). Champaign, IL: Human Kinetics.

Morgan, W.P. (1985). Psychogenic factors and exercise metabolism. Medicine and Science in Sports and Exercise, 17, 309-316.

Morgan, W.P., O'Connor, P.J., Sparling, P.B., & Pate, R.R. (1987). Psychological characterization of the elite female distance runner. International Journal of Sports Medicine, 8, 124-131.

Morgan, W.P., & Pollock, M.L. (1977). Psychological characterization of the elite distance runner. Annuals of New York Academy of Science, 301, 382-403.

Pennebaker, J.W., & Lightner, J.M. (1980). Competition of internal and external information in an exercise setting. Journal of Personality and Social Psychology, 19, 165-174.

Sims, J., & Carroll, D. (1990). Cardiovascular and metabolic activity at rest and during psychological and physical challenge in normotensives and subjects with mildly elevated blood pressure. Psychophysiology, 27, 149-156.

Taylor, H.R., Buskirk, E.R., & Henschel, A. (1955). Maximal oxygen intake as an objective measure of cardio-respiratory performance. Journal of Applied Physiology, 8, 73-80.

Turner, J.R., Carroll, D., Hanson, J., & Sims, J. (1988). A comparison of additional heart rates during active psychological challenge calculated from upper body and lower body dynamic exercise. Psychophysiology, 25, 209-216.

Weinberg, R.S., Jackson, A., & Gould, D. (1984). Effect of association, dissociation, and positive self-talk on endurance performance. Canadian Journal of Applied Sport Science, 9, 25-32.

Williams, T.J., Krahenbuhl, G.S., & Morgan, D.W. (1991). Mood state and running economy in moderately trained male runners. Medicine and Science in Sports and Exercise, 23, 727-731.