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Biomedical subjects

W P Morgan

Publications and source records attributed to W P Morgan.

At least 19 recordsLinked to original sources
PubMed1992

The effect of imagery perspectives on the psychophysiological responses to imagined exercise.

The effect of imagery perspectives, i.e. internal imagery vs. external imagery, on the psychophysiological responses to imagined exercise was investigated in the present study. Thirty male and female college students were randomly assigned to perform either internal imagery, external imagery or simple rest in addition to actual exercise. Metabolic, cardiovascular and perceptual responses were recorded before, during and after imagined exercise, actual exercise and rest. The results indicated that internal imagery resulted in a significant increase in ventilation and this response differed from the control condition. Effort sense was higher with internal imagery compared with external imagery. However, both internal and external imagery produced significant elevations in systolic blood pressure (SBP) from pre- to post-imagery, and these values were identical to those observed with actual exercise. Therefore, some responses to imagery were like those seen during actual exercise. Oxygen consumption (VO2), respiratory rate (RR), respiratory exchange ratio (RER), heart rate (HR) and diastolic blood pressure (DBP) were similar between internal and external imagery. It is concluded that the psychophysiological responses to internal imagery resemble actual exercise more than external imagery.

Adolescent↗
PubMed1992

Efficacy of perceptual versus heart rate monitoring in the development of endurance.

The purpose of this investigation was to compare the effectiveness of using ratings of perceived exertion (RPE) with heart rate in the monitoring of exercise intensity during aerobic dance instruction. Thirty-eight students who enrolled in aerobic dance classes used heart rate to monitor exercise intensity while 38 additional students used RPE to monitor exercise intensity during a 14-week course. Classes met twice a week for 50 min and all outside workouts were recorded. The groups did not differ with respect to the number of outside workouts. The dependent variable was endurance performance as measured by the distance run in 15 min. Data were analysed with a repeated measures analysis of variance (ANOVA) for multifactor experiments. There were significant trials (P less than 0.0001) and interaction (P less than 0.05) effects, and both groups improved significantly in endurance performance during 14 weeks of training. However, the group using RPE to monitor exercise intensity had a significantly greater gain in endurance. The heart rate group had a mean increase of 6% (166 m) whereas the RPE group increased 11% (274 m). It is concluded that during aerobic dance the monitoring of exercise intensity with RPE is associated with greater improvement in endurance than is heart rate monitoring.

Adult↗
PubMed1991

Elective laparoscopic cholecystectomy for "all-comers".

Laparoscopic cholecystectomy is a safe and effective procedure in specialist centres, but its wider application will depend on the ability of general surgeons to become skilled in this technique. 180 patients underwent elective laparoscopic cholecystectomy during a nine-month period at a single district general hospital. All patients who would have been eligible for elective open cholecystectomy were offered the laparoscopic alternative. Laparoscopic cholecystectomy was abandoned in favour of an open procedure in 10 (6%) patients. Median operating time was 55 min. 2 patients had serious morbidity (right hepatic duct injury and a duodenal fistula) and there were no deaths. 3 patients required subsequent treatment for retained common duct stones. 90% of patients were discharged within 48 h of the operation and the median time to resume full activity after discharge was 12 days. Laparoscopic cholecystectomy is a safe and cost-effective technique in a district general hospital.

Adult↗
PubMed1991

Perception of effort in female and male competitive swimmers.

The primary purpose of this investigation was to compare 31 competitive female swimmers with 31 competitive male swimmers on their perceptual responses to submaximal swimming. A secondary purpose was to evaluate the relationship between heart rate (HR) and perceived exertion (RPE) in swimming. Each swimmer completed a 200-yd swim in his/her specialty stroke at 90% of the swimmer's current best time. Underwater and overhead pace lights were used to achieve an even pace during the swims, and HR was monitored by means of radiotelemetry. Ratings of overall and local perceived exertion were assessed immediately following each swim with Borg's 6-20 scale. ANOVA revealed no RPE differences across stroke classifications for the female or male swimmers, but local and overall RPE were lower (p less than 0.01) in the females. Mean HR, however, was significantly higher (p less than 0.05) for the female swimmers. Unlike research with other exercise modes, correlational analyses revealed that overall and local RPE were unrelated to HR (p greater than 0.05). Based on these findings, it is concluded that 1) female swimmers judged a paced swim to be less effortful than did male swimmers despite a greater objective strain in the females, and 2) HR was not correlated with perception of effort.

Adolescent↗
PubMed1991

Changes in mood states during training in female and male college swimmers.

The changes occurring in specific mood states in response to alterations in physical training were assessed in college varsity swimmers. The Profile of Mood States (POMS) was administered at regular intervals during training seasons over a four-year period to 84 female and 102 male swimmers. It was found that female and male swimmers displayed similar mood responses during training in total mood as well as the specific moods of depression, anger, vigor, fatigue, and confusion. Each of these mood states fluctuated correspondingly with alterations in training yardage, with the exception of tension, which remained elevated while training was being reduced. Tension also was higher (p less than 0.05) in the female swimmers in each of the seasons. It is concluded that: 1) changes in specific mood states during training are similar between female and male swimmers, with the exception of tension, and 2) specific mood factors increase and decrease in accordance with alterations in training distance, with the exception of tension, which does not decrease in response to reductions in training.

Adult↗
PubMed1991

Air travel across four time zones in college swimmers.

Eighteen female and 22 male college swimmers were flown across four time zones in east-to-west (E-W) and west-to-east (W-E) directions. A pre- and postflight paced swim of 182.9 m at an intensity equal to 90% of the swimmers' maximal velocity was completed, and salivary cortisol, heart rate (HR), and rated perceived exertion were measured. Blood pressure, HR, muscle soreness, and mood were also assessed at rest on the day before and on the day after travel. Because training volumes for both females and males were greater (P less than 0.001) in the week before W-E than E-W travel, the W-E and E-W data were analyzed separately. Two-way repeated-measures analyses of variance revealed that pre- and postexercise cortisol decreased after E-W travel and increased after W-E travel in comparison to preflight values. Resting and exercise HR responses to air travel were small in magnitude, and their significance depended on the direction of travel. Effort sense was not altered by air travel, but significant (P less than 0.001) improvements in mood and reductions in muscle soreness were observed after E-W and W-E travel for both genders. It was concluded that 1) female and male college swimmers have similar responses to air travel and 2) air travel across four time zones during heavy swim training does not have negative physiological, perceptual, or affective consequences.

Adolescent↗
PubMed1991

Psychobiologic effects of 3 d of increased training in female and male swimmers.

Eighteen female and 22 male college swimmers completed a paced 182.9 m swim before and after a 72 h period of increased training. Training volume was increased from 6,800 to 11,200 m.d-1 for the females and from 8,800 to 12,950 m.d-1 for the males. Salivary cortisol, heart rate, stroke mechanics, as well as overall and local ratings of perceived exertion (RPE) were measured in conjunction with the two swim tests. Mood states, as measured by the Profile of Mood States, and ratings of perceived muscle soreness were assessed daily. Significant (P less than 0.005) elevations in stroke frequency, overall and local RPE, fatigue, overall mood, and muscle soreness levels occurred in association with the increased training. Significant (P less than 0.005) reductions in vigor and stroke length were also observed as a consequence of the greater training load. The main effects for gender and the gender by trial interactions were not significant for each variable tested. It was concluded that: 1) affective, biomechanical, and perceptual variables are sensitive to a 3 d increase in the volume of swim training, 2) heart rate and cortisol levels are not influenced by the type of increased training employed in this study, and 3) female and male college swimmers do not differ in their psychological or physiological responses to a rapid increase in training volume.

Adolescent↗
PubMed1990

Pre-competition anxiety and performance in female high school swimmers: a test of optimal function theory.

This investigation attempted to test Hanin's theory of optimal function in 15 female high school swimmers. Each swimmer completed the State Anxiety Inventory (STAI) and the Body Awareness Scale (BAS) under the following conditions: I) baseline; II) retrospective recall of "best", "usual", and "worst" performances; III) 24 h prior to an easy and difficult dual meet with instructions to respond as to "how you think you will feel 1 h before the meet"; and IV) 1 h before the meets utilizing the standard ("right now") instructional set. Success was determined in each meet by two methods: 1) objective ratings based on comparisons with the average of times from previous meets; and 2) subjective ratings of performance made by the coach. In the difficult meet significant (P less than 0.01) increases in precompetition anxiety and body awareness occurred, and the correlations between predicted and actual pre-competition were .95 (P less than 0.001) for both anxiety and body awareness. In the difficult meet swimmers subjectively classified as successful were more accurate (P less than 0.05) in predicting precompetition anxiety, and possessed pre-competition anxiety values that were closer to their recall of optimal pre-competition anxiety compared to the unsuccessful swimmers. No comparisons based on the objective classifications were significant, nor were any of the comparisons in the easy meet. The present findings support Hanin's optimal function theory.

Adolescent↗
PubMed1990

Mood and self-motivation in successful and unsuccessful female rowers.

Mood state (POMS) and self-motivation (SMI) were assessed in 84 women vying for a position on a collegiate freshman rowing team. Forty-four of these rowers also completed a standardized rowing ergometer task. Mood state was assessed three additional times during the season with 22 rowers who adhered to training throughout the entire season. No differences (P greater than 0.05) in baseline mood state were observed between the dropouts (N = 62) and those who adhered to the training (N = 22). However, the dropouts possessed significantly lower self-motivation (P less than 0.05) and took longer to complete the rowing task than did the adherers (P less than 0.05). Near the end of the season, rowers were chosen by the coaching staff to compete in regional competition (i.e., successful adherers). Initial self-motivation and ergometer performance did not differ significantly (P greater than 0.05) between the successful and unsuccessful adherers. Repeated measures ANOVA revealed that global mood disturbance (P less than 0.05) increased during the training season in both groups. At the end of the training season, the unsuccessful adherers still possessed significantly (P less than 0.05) elevated mood disturbance, whereas the mood of the successful group had returned to baseline. It is concluded that female rowers who adhere to a season of competitive training have higher self-motivation and superior ergometer performances at the outset than do the eventual dropouts.

Affect↗
PubMed1990

Athletic performance following rapid traversal of multiple time zones. A review.

Athletes travel across multiple time zones in order to engage in national or international competition. It has often been assumed that rapid transmeridian translocation has a negative impact on athletic performance. However, the available studies are characterised by major methodological problems. Consequently, no compelling evidence exists demonstrating that air travel adversely influences athletic performance. Evidence suggests that distance and sprint running performance, as well as dynamic muscular strength and endurance of the elbow flexors, is impaired following west-east travel across 6 times zones in untrained individuals. However, there is no evidence that these findings for untrained subjects generalise to athletes. Both physiological and psychological mechanisms might account for potential effects of travel on athletic performance, but little is known about these potential mechanisms with regards to athletic performance. Systematic research is needed if the relationship between air travel and athletic performance is to be elucidated.

Aircraft↗
PubMed1989

Mood state and salivary cortisol levels following overtraining in female swimmers.

Mood, as measured by the Profile of Mood States questionnaire, and resting salivary cortisol levels were examined in 14 female college swimmers during progressive increases and decreases in training volume, and were compared to the same measures in eight active college women who served as controls. Training volume increased from 2,000 yards/day in September (baseline) to a peak of 12,000 yards/day in January (overtraining), followed by a reduction in training (taper) to 4,500 yards/day by February. The swimmers experienced significant (p less than 0.01) alterations in tension, depression, anger, vigor, fatigue and global mood across the training season compared to the controls. Salivary cortisol was significantly (p less than 0.01) greater in the swimmers compared to the controls during baseline and overtraining, but was not different between the groups following the taper. Salivary cortisol was significantly correlated with depressed mood during overtraining (r = .50; p less than 0.05) but not at baseline or taper. Global mood, depression, and salivary cortisol were significantly (p less than 0.05) higher during the overtraining phase in those swimmers classified as stale, compared to those swimmers who did not exhibit large performance decrements.

Affect↗
PubMed1989

Effects of pressure-demand respirator wear on physiological and perceptual variables during progressive exercise to maximal levels.

Current regulations governing the certification of respiratory protective devices are based on data published in the early 1950s. The limited data base of this early work and documented increases in the average height of the population underscore the need for additional information concerning the parameters of certification. In the present study, a protocol using an inclined treadmill (0.5% grade every 12 sec) was used to test a heterogeneous population (n = 38). Through submaximal up to and including maximal exercise levels with and without respirator wear, maximal oxygen uptake (VO2max) was significantly greater (p less than 0.01) with the respirator (44.11 +/- 1.3 mL/kg.min) than without the respirator (42.18 +/- 1.4 mL/kg.min) while maximal ventilation volumes (VEmax) were not significantly different (with = 118.7 +/- 4 L/min; without 119.6 +/- 5 L/min). While peak inspired flows (PFI) with the respirator (268 +/- 7 L/min) were less than without the respirator (281 +/- 9 L/min), p greater than 0.05, the lower peak expired flow (PFE) with the respirator (289 +/- 12 L/min) than without the respirator (324 +/- 13 L/min), p less than 0.01, indicated a significant blunting effect of the respiratory flows by the expired resistance during exercise to maximal levels. Peak inspired pressures (PPi) with and without the respirator were not significantly different (p greater than 0.05). The negative values obtained within the facepiece of the respirator (-7.65 +/- 0.8 cmH2O), however, indicate that the positive pressure within the facepiece was lost, and respiratory protection may be compromised. Peak expired pressure with the respirator (13.05 +/- 0.7 cmH2O) was significantly greater than without the respirator (10.7 +/- 0.5 cmH2O) indicating that, despite a lower PFE, greater force was required to overcome the resistances of the respirator on expiration. The dyspnea index, an index of physiological effort; suggests that the subjects were working at a higher percentage of their respiratory reserve with the respirator (p less than 0.05) than without. Perceptually, subjects also felt that breathing with the respirator was more difficult (p less than 0.05). The maximum heart rate and the ratings of perceived exertion were not significantly different between the two tests at maximal exercise levels. Maximum oxygen uptake was considered reached when subjects attained a respiratory exchange ratio of at least 1.15, when a heart rate response at or greater than age-predicted maximum was achieved, when ratings of perceived exertion indicated exhaustion, and/or when the measure of VO2 had plateaued during the final minute of exercise.(ABSTRACT TRUNCATED AT 400 WORDS)

Equipment Design↗
PubMed1989

Alterations in physiological and perceptual variables during exhaustive endurance work while wearing a pressure-demand respirator.

The purpose of this investigation was to describe the time course of changes in physiological and perceptual variables during exhaustive endurance work with and without an air-supplied, full-facepiece, pressure-demand respirator. Thirty-eight healthy subjects (24 to 51 years of age) volunteered for this study. Treadmill speed was set at 5.5 kph (3.4 mph) and elevation was set at a level calculated to elicit 70% of a previously determined maximal aerobic capacity (VO2max). Subjects continued at this rate to exhaustion. Despite a constant work rate, VO2 and %VO2max increased during exercise and were significantly greater with the respirator (34.4 +/- 1.1 mL/kg.min; 84% VO2max) than without the respirator (31.9 +/- 1.1 mL/kg.min; 76% VO2max) at the "final" measurement point prior to termination of exercise by each subject. The final values for ventilation volume (VE) also were significantly greater with the respirator (89.2 +/- 3.4 L/min) than without (73.4 +/- 3.7 L/min). At the conclusion of the endurance walk, dyspnea index (VE/MMV.25) remained well below maximal values (with = 58.6 +/- 2%; without = 44.6 +/- 2%; p less than 0.001). Also, at the final period, no significant differences occurred in the subjects' perceptual ratings of work of breathing, yet work performance time was significantly reduced (p less than 0.0001) from 69.1 +/- 4.4 min (without) to 55.6 +/- 3.8 min (with). A significantly greater swing in peak pressure (maximum pressure measured within the facepiece of respirator), however, from inspired (PPi) to expired (PPe) occurred with the respirator (13.42 cmH2O) than without the respirator (9.25 cmH2O).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Exercise and self-esteem: rationale and model.

Positive emotional and psychological benefits are commonly believed to result from chronic physical exercise. While reviews of research have failed to substantiate this general proposition, they have identified enhanced self-esteem as an empirically supported exercise outcome. Unfortunately, research in this area has tended to be simplistic in self-esteem theory and measurement and has remained incapable of addressing how or why change may occur. This paper summarizes pertinent self-esteem theory and presents an empirically based rationale for self-esteem enhancement through exercise participation. It constructs a model for examining exercise and self-esteem interactions in which components of self-structure are hierarchically organized on a basis of generality. The self-esteem model contains dimensions of competence and self-acceptance, and it is operationally defined.

Exercise↗
PubMed1988

Mood disturbance following increased training in swimmers.

Twelve male swimmers were studied psychologically before, during, and after 10 d of increased training. Daily training distance was increased from 4,000 to 9,000 m.d-1, and intensity was maintained at 94% of VO2max. Three of the swimmers were unable to tolerate the increased training load, and they did the same distance at slower speeds. Swimmers completed the Profile of Mood States, a muscle soreness scale, and a 24-h history each morning prior to the first of two daily training sessions. Changes across days were evaluated statistically with a one-way repeated measures ANOVA. Significant (P less than 0.005) increases occurred in the ratings of exercise intensity, muscle soreness, depression, anger, fatigue, and global mood disturbance, along with a reduction in general sense of well-being. Swimmers were classified as "responders" or "non-responders" on the basis of distress patterns using separate physiological and psychological criteria, and these classifications were performed in a double-blind setting. Close agreement (89%) was achieved between the psychometric and physiological judgments, and the physiological results appear in related papers. It is concluded that significant psychometric changes occur with an intense 10-d training regimen, and these alterations resemble those observed in swimmers exposed to increased training across several months. These findings underscore the potential utility of monitoring mood states in the prevention of staleness.

Adolescent↗
PubMed1987

Psychological monitoring of overtraining and staleness.

It is widely agreed that overtraining should be employed in order to achieve peak performance but it is also recognised that overtraining can actually produce decrements in performance. The challenge appears to be one of monitoring stress indicators in the athlete in order to titrate the training stimulus and prevent the onset of staleness. The present paper summarises a ten-year research effort in which the mood states of competitive swimmers have been monitored at intervals ranging from 2-4 weeks during individual seasons for the period 1975-1986. The training cycle has always involved the indoor season which extends from September to March and the athletes who served as subjects were 200 female and 200 male competitive swimmers. The results indicate that mood state disturbances increased in a dose-response manner as the training stimulus increased and that these mood disturbances fell to baseline levels with reduction of the training load. Whilst these results have been obtained in a realistic setting devoid of experimental manipulation, it is apparent that monitoring of mood state provides a potential method of preventing staleness.

Affect↗