Purpose: To determine the effect of submaximal steady-state exercise on cognitive performance in patients with chronic fatigue syndrome (CFS) alone, CFS with comorbid fibromyalgia FM (CFS+FM), and sedentary healthy controls (CON). Methods: Twenty CFS-only patients, 19 CFS+FM, and 26 CON completed a battery of cognitive tests designed to assess speed of information processing, variability, and efficiency. Tests were performed at baseline, immediately before, and twice following 25 min of either cycle ergometry set at 40% of peak oxygen capacity or quiet rest. Results: There were no group differences in average percentage of peak oxygen consumption during exercise (CFS = 45%; CFS+FM = 47%; Control = 43%: P = 0.2). There were no significant effects of acute exercise on cognitive performance for any group. At baseline, one-way ANOVA indicated that CFS patients displayed deficits in speed of processing, performance variability, and task efficiency during several cognitive tests compared with healthy controls. However, the CFS+FM patients were not different than controls. Repeated measures ANOVA indicated that across all tests (pre- and postexercise) CFS, but not CFS+FM, were significantly less consistent (F2,59 = 3.7,P = 0.03) and less efficient (F2,59 = 4.6,P = 0.01) than controls. Conclusion: CFS patients without comorbid FM exhibit subtle cognitive deficits in terms of speed, consistency, and efficiency that are not improved or exacerbated by light exercise. Importantly, our data suggest that CFS+FM patients do not exhibit cognitive deficits either pre- or postexercise. These results highlight the importance of disease heterogeneity in studies determining acute exercise and cognitive function in CFS.

1876 Patients with Chronic Fatigue Syndrome (CFS) exhibit subtle impairment in concentration, attention and short-term memory, referred to as neurocognitive symptoms. These symptoms are reported to be exacerbated following physical exertion. However, recent reports suggest that CFS patients can perform a short, maximal bout of exercise without significant deficits in cognitive performance. The main limitations of these studies are the use of variable duration maximal exercise, failure to include a no-exercise control condition and no control for co-morbid unexplained illness, specifically the presence of Fibromyalgia (FM). Therefore, the effect of exercise on neurocognitive function in CFS has not been adequately determined. PURPOSE: To determine the effect of longer duration submaximal exercise on neurocognitive performance in patients with CFS, CFS with co-morbid FM (CFS+FM) and sedentary healthy controls (CON). METHODS: Twenty CFS patients (n = 9 exercise; n = 11 no exercise), 19 CFS+FM (n = 12 exercise; n = 7 no exercise) and 26 CON (n = 14 exercise; n = 12 no exercise) completed a battery of neurocognitive tests designed to assess speed of information processing, variability and efficiency. Tests were performed at baseline, immediately prior to and twice following 25 min of either cycle ergometry set at 40% of peak oxygen capacity or quiet rest. RESULTS: There were no group differences in average oxygen consumption during exercise (CFS = 45%; CFS+FM = 47%; Control = 43%: p = 0.2). Repeated measures ANOVA revealed a main effect for time for all groups across most cognitive measures, demonstrating improved cognitive performance. There were no significant effects of exercise on cognitive performance for any group or cognitive measure. At baseline, one-way ANOVAs indicated that CFS patients displayed impairments in speed of processing, performance variability and task efficiency during several cognitive tests. However, the CFS+FM patients were not different than controls. Repeated measures ANOVA indicated that across all tests (pre and post exercise) CFS, but not CFS+FM, were significantly more variable (F2,59 = 3.7, p = 0.03) and less efficient (F2,59 = 4.6, p = 0.01) than controls. CONCLUSION: CFS patients without co-morbid FM exhibit subtle cognitive impairment in terms of speed, consistency and efficiency that is not improved or exacerbated by light exercise. Importantly, our data suggest that CFS+FM patients do not exhibit cognitive impairment either pre or post exercise. This highlights the importance of disease heterogeneity in unexplained illness. Supported by NIH AI-32247

PURPOSE:It has been reported that ratings of perceived exertion (RPE) are elevated in chronic fatigue syndrome (CFS). We have challenged this notion by examining perceived exertion in civilian females with CFS and expressing the data relative to exercise capacity (%[OV0312]O(2max)). The purpose of the present investigation was to further examine RPE during exercise in a unique population of CFS patients, Gulf veterans (GV).METHODS:Thirty-four GV (N = 15 CFS, 42 +/- 8 yr; N = 19 healthy, 43 +/- 5 yr) performed a maximal exercise test on a cycle ergometer. After a 3-min warm-up, exercise intensity increased by 30 W every minute until exhaustion. RPE were obtained during the last 15 s of each minute using Borg's CR-10 scale.RESULTS:With the exception of peak [OV0312]E, there were no significant differences in any peak exercise variables. Repeated measures ANOVA revealed significantly higher RPE at each power output examined (F(1,32) = 16.4, P < 0.001). Group differences in RPE remained significant when analyzed relative to peak [OV0312]O(2) (F(1,32) = 7.2, P = 0.01). Both group main effects and the interaction were eliminated when self-reported fatigue symptoms were controlled for in the analyses. Power functions for RPE as a function of relative oxygen consumption were not different between groups and were significantly greater than a linear value of 1.0 (1.6 +/- 0.3 for both groups, P < 0.02).CONCLUSIONS:Our results show that RPE are greater in GV with CFS regardless of whether the data were expressed in terms of absolute or relative exercise intensity. However, self-reported fatigue associated with CFS eliminated the group differences. These results suggest that GV with CFS were unique compared with their civilian counterparts. Future research aimed at determining the influence of preexisting fatigue on RPE during exercise is warranted.

Background: Findings indicative of a problem with circulation have been reported in patients with chronic fatigue syndrome (CFS). We examined this possibility by measuring the patient's cardiac output and assessing its relation to presenting symptoms. Methods: Impedance cardiography and symptom data were collected from 38 patients with CFS grouped into cases with severe (n = 18) and less severe (n = 20) illness and compared with those from 27 matched, sedentary control subjects. Results: The patients with severe CFS had significantly lower stroke volume and cardiac output than the controls and less ill patients. Postexertional fatigue and flu-like symptoms of infection differentiated the patients with severe CFS from those with less severe CFS (88.5% concordance) and were predictive (R-2 = 0.46, P < 0.0002) of lower cardiac output. In contrast neuropsychiatric symptoms showed no specific association with cardiac output. Conclusions: These results provide a preliminary indication of reduced circulation in patients with severe CFS. Further research is needed to confirm this finding and to define its clinical implications and pathogenetic mechanisms.

A large overlap exists between the diagnosis of chronic fatigue syndrome (CFS) and the unexplained symptoms reported by many Gulf War veterans (GV). Previous investigations have reported reduced aerobic capacity in civilians with CFS. The present investigation examined metabolic responses to maximal exercise in GVs with CFS compared with healthy GVs. Cardiorespiratory and metabolic responses were recorded during a maximal exercise test on a cycle ergometer. The groups were not different in any demographic category (p > 0.05) or self-reported physical activity (p > 0.05). No differences were observed between groups for maximal oxygen uptake (28.9 +/- 6.7 mL/kg/min for CFS vs. 30.8 +/- 7.1 mL/kg/min for controls; p = 0.39), heart rate (155.8 +/- 16.1 bpm for CFS vs. 163.3 +/- 14.9 bpm for controls; p = 0.17), exercise time (9.6 +/- 1.5 minutes for CFS vs. 10.2 +/- 1.4 minutes for controls; p = 0.26), or workload achieved (208 +/- 36.7 W for CFS vs. 224 +/- 42.9 W for controls; p = 0.25). Likewise, no differences were observed at submaximal intensities (p > 0.05). Compared with healthy controls, GVs who report multiple medically unexplained symptoms and meet criteria for CFS do not show a decreased exercise capacity. Thus, it does not appear that the pathology of the GVs with CFS includes a deficiency with mobilizing the cardiopulmonary system for strenuous physical effort.

OBJECTIVE:Altered cardiovascular responses to mental and postural stressors have been reported in chronic fatigue syndrome (CFS). This study examined whether those findings may involve changes in baroreceptor reflex functioning. METHODS:Chronotropic baroreceptor reflex (by sequential analysis) and cardiovascular stress responses were recorded during postural (5-minute of active standing) and cognitive (speech task) stress testing in patients with CFS grouped into cases with severe (N = 21) or less severe (N = 22) illness, and in 29 matched control subjects. RESULTS:Patients with CFS had a greater decline in baroreceptor reflex sensitivity (BRS) during standing, although only those with severe CFS were significantly different from the controls. Systolic blood pressure declined during standing in the control group but was maintained in the CFS patients. In contrast, the patients with less severe CFS had blunted increases in blood pressure during the speech task, which could not, however, be explained by inadequate inhibition of the baroreceptor reflex, with all groups showing an appropriate reduction in BRS during the task. CONCLUSIONS:These results indicate that in CFS, deficiencies in orthostatic regulation, but not in centrally mediated stress responses, may involve the baroreceptor reflex. This study also suggests that classifying patients with CFS on illness severity may discriminate between patients with abnormalities in peripheral vs. central mechanisms of cardiovascular stress responses.

Abnormal cardiovascular stress responses have been reported in Gulf War veterans with chronic fatigue. However, many of these veterans also suffer from posttraumatic stress disorder (PTSD), which could potentially explain the reported abnormalities. To test this hypothesis, 55 Gulf veterans (GVs) with chronic fatigue syndrome (CFS) or idiopathic chronic fatigue (ICF) were stratified into groups with (N=16) and without (N=39) comorbid PTSD, and were compared to healthy Gulf veterans (N=47) on cardiovascular responses to a series of stressors. The CFS/ICF with PTSD group had lower blood pressure responses to speech and arithmetic tasks, and more precipitous declines and slower recoveries in blood pressure after standing up than the controls. Similar trends in the CF/ICF group without PTSD were not significant, however. Both CFS/ICF groups had blunted increases in peripheral vascular resistance during mental tasks. However, only the veterans with comorbid PTSD had diminished cardiac output responses to the mental stressors and excessive vasodilatory responses to standing. Symptoms of posttraumatic stress were significant predictors of hypotensive postural responses, but only in veterans reporting a significant exposure to wartime stress. We conclude that comorbid PTSD contributes to dysregulation of cardiovascular responses to mental and postural stressors in Gulf veterans with medically unexplained fatiguing illness, and may provide a physiological basis for increased somatic complaints in Gulf veterans with symptoms of posttraumatic stress.

CFS is a serious disabling illness, characterized by severe and chronic fatigue, with rheumatological, infectious, and neuropsychiatric symptoms. In the absence of any specific organ or system to treat, therapy for CFS is experimental and often includes mild physical exercise. However, many patients complain that exercise exacerbates their symptoms. PURPOSE To determine the effects of a monitored aerobic exercise program on CFS symptoms. METHODS Twenty-three CFS patients (CFS-TR) and 18 healthy, sedentary subjects (CON-TR) participated in a three day per week treadmill walking program for 10 weeks. Training intensity progressed to 50% peak oxygen uptake during the last six weeks. Twelve CFS and seven CON were used for nontraining groups. All subjects performed a graded cardiopulmonary treadmill exercise test (CPX) pre and post 10 weeks. On each training day feelings of well-being and ratings of muscle soreness were ascertained. Pre and post 10 weeks, symptoms of CFS were assessed utilizing a packet of questionnaires that included the following: Multi-Fatigue Index, Medical Outcomes Study SF36, Profile of Mood States, and Beck Depression Inventory (BDI). RESULTS Two CFS-TR patients withdrew for reasons not attributed to symptom exacerbation. None of the metabolic variables measured during the CPX significantly changed for any group (all p > .05). Total CPX exercise time increased for the training groups (p < .04). The ratings of perceived exertion at absolute and relative workloads decreased for the CFS-TR (p < .05). Feelings of well-being and ratings of muscle soreness did not change for the CFS-TR (all p > .05). BDI scores for all CFS patients decreased over time (p < .05) but no significant changes were seen for any of the additional variables measured with the symptom questionnaires (all p > .05). CONCLUSION CFS patients can tolerate mild to moderate aerobic exercise; training improved exercise tolerance but did not improve or exacerbate CFS symptoms. Supported by NIH Center Grant U01 AI-32247.

OBJECTIVE:The purpose of this study was to compare the cardiovascular responses of patients with chronic fatigue syndrome (CFS) to healthy control subjects when performing stressful cognitive tasks before and after strenuous exercise.METHOD:Beat-by-beat blood pressure and electrocardiogram were recorded on 19 women with CFS and 20 healthy nonexercising (ie, sedentary) women while they performed cognitive tests before, immediately after, and 24 hours after incremental exercise to exhaustion.RESULTS:Diminished heart rate (p <.01) and systolic (p <.01) and diastolic (p <.01) blood pressure responses to stressful cognitive testing were seen in patients with CFS when compared with healthy, sedentary controls. This diminished stress response was seen consistently in patients with CFS across three separate cognitive testing sessions. Also, significant negative correlations between self-ratings of CFS symptom severity and cardiovascular responses were seen (r = -0.62, p <.01).CONCLUSIONS:Women with CFS have a diminished cardiovascular response to cognitive stress; however, exercise did not magnify this effect. Also, the data showed that the patients with the lowest cardiovascular reactivity had the highest ratings of CFS symptom severity, which suggests that the individual response of the patient with CFS to stress plays a role in the common complaint of symptoms worsening after stress.

The present study examined whether alterations in the cardiac baroreceptor reflex in hypertension may be a function of constitutional differences associated with gender and age. These hypotheses were tested using a cross-sectional design that compared 20 normotensive and 21 hypertensive men and women of varying age for differences in baroreceptor reflex sensitivity and response latency for heart rate, obtained using a modified bolus phenylephrine (Oxford) method. Relative to their respective normotensive controls, baroreceptor reflex sensitivity was reduced in hypertensive men, but not in hypertensive women. Among normotensive subjects, men had greater baroreceptor reflex sensitivity than women. Independent from the effects associated with differences in blood pressure, age was not a significant predictor of reduction in baroreceptor reflex sensitivity. However, a combination of high blood pressure and older age was associated with a significant increase in baroreceptor reflex response time. In summary, gender and aging interacted with hypertension to alter two different aspects of the baroreceptor reflex. These results provide a preliminary indication that a decline in arterial baroreflex sensitivity may be more specific to hypertension in men than in women. Prolongation in baroreflex response latency in older hypertensive subjects also suggested that aging and hypertension may have a synergistic effect on cardiac parasympathetic function.

An important question for researchers interested in long-term consequences of military service is the health outcome of symptomatic Persian Gulf War Veterans. From an original group of 76 Gulf War Veterans who received the diagnosis of severe fatiguing illness, we attempted to get 58 veterans to return to our center for a second evaluation. Thirteen returned. Two had recovered by the time of revisit, but the rest remained ill; however, only one was so ill as to be unable to work. The data suggest that the medical consequences of serving in the Persian Gulf are not transient. The difficulty in getting veterans to return to our center suggests potential problems in the proposed nation-wide longitudinal health outcome study of Persian Gulf War Veterans.

INTRODUCTION: It has been reported that ratings of perceived exertion (RPE) are elevated in chronic fatigue syndrome (CFS). However, methodological limitations have rendered this conclusion suspect. Additionally, it is unknown whether all fatiguing illness is associated with altered perceptions of exertion. Here we report on the RPE in 2 very different groups of individuals (female civilians and male Gulf Veterans (GVs)) with CFS. The primary purpose of the present investigation was to compare RPE in CFS among GVs and non-veterans. A second purpose was to provide recommendations for future research based on limitations in this and previous work. METHODS: 32 GVs (n = 18 healthy; n = 14 CFS) performed a maximal exercise test on a cycle ergometer. Following a 3-min warm-up, exercise intensity increased 30 watts/min until exhaustion. RPE (0–10) was obtained in the last 15 sec of each min. A second sample of 39 non-veterans (n = 20 healthy; n = 19 CFS) underwent max testing on a treadmill. Exercise began with a 3-min warm-up at 2.5 mph/0% incline. After the initial stage, treadmill speed was increased to 3.5 mph for 3 min and then incline was increased by 2% every 3 min until exhaustion. RPE (6–20) was obtained during the last 30 seconds of each 3-min stage. For both samples, HR, VO2, and VCO2 were measured continuously. RESULTS: For GVs, there were no significant differences in any peak exercise variable. GVs with CFS reported higher RPE at each absolute power output examined (F1,24 = 13, p = 0.001). Group differences in RPE remained significant when analyzed relative to peak VO2 (F1,30 = 6.2, p = 0.02). For the non-vets, there were no differences in peak VO2, RER, or RPE. Non-vet controls exercised 4 min longer (p = 0.037) and had higher peak HR (p = 0.03). Non-vets with CFS reported higher RPE at each exercise stage compared to controls (F1,33 = 5.4, p = 0.026). When RPE was expressed relative to peak VO2 there were no group differences (F1,35 = 2.4, p = 0.13). CONCLUSIONS: Our results show that RPE is greater in both GVs and non-vets with CFS in terms of absolute exercise intensity. However, when RPE is expressed relative to a common maximum the non-vets did not differ from controls. This finding is consistent with one other published study from our group. Contrary to our hypothesis, RPE in GVs with CFS remained higher than controls when expressed relative to peak VO2. These results suggest that GVs with CFS are unique compared to their civilian counterparts. Unfortunately, as is the problem with previous work with RPE in this population, different methodologies limit our ability to directly compare these groups. It is recommended that future research in fatiguing illness use standard scales and instructions, common modes of exercise, express data relative to a common max, and examine physiological correlates of RPE. Support: DVA NJ Ctr Environ Hazards Res 561-003; NIH u01 AI-32246

Objective The objective of this study was to examine whether inappropriate cardiovascular responses to stressors may underlie symptoms in Gulf War veterans with chronic fatigue. Methods Psychophysiological stress testing was performed on 51 Gulf War veterans with chronic fatigue (using the 1994 case definition of the Centers for Disease Control and Prevention) and 42 healthy veterans. Hemodynamic responses to cold pressor, speech, and arithmetic stressors were evaluated using impedance cardiography. Results Veterans with chronic fatigue had diminished blood pressure responses during cognitive (speech and arithmetic) stress tests due to unusually small increases in total peripheral resistance. The cold pressor test, however, evoked similar blood pressure responses in the chronic fatigue and control groups. Low reactivity to cognitive stressors was associated with greater fatigue ratings among ill veterans, whereas an opposite relation was observed among healthy veterans. Self-reported neurocognitive decline was associated with low reactivity to the arithmetic task. Conclusions These results suggest a physiological basis for some Gulf War veterans’ reports of severe chronic fatigue. A greater deficit with responses processed through cerebral centers, as compared with a sensory stimulus (cold pressor), suggests a defect in cortical control of cardiovascular function. More research is needed to determine the specific mechanisms through which the dissociation between behavioral and cardiovascular activities identified in this study may be contributing to symptoms in Gulf War veterans.

This study examined the cardiovascular response to orthostatic challenge, and incidence and mechanisms of neurally mediated hypotension in chronic fatigue syndrome (CFS) during a head-up tilt test. Stoke volume was obtained by a thoracic impedance cardiograph, and continuous heart rate and blood pressure were recorded during a 45-min 70 degrees head-up tilt test. Thirty-nine CFS patients and 31 healthy physically inactive control subjects were studied. A positive tilt, i.e. a drop in systolic blood pressure of > 25 mmHg, no concurrent increase in heart rate and/or development of presyncopal symptoms, was seen in 11 CFS patients and 12 control subjects (P > 0.05). During baseline and the first 5 min of head-up tilt, CFS patients had higher heart rate and smaller pulsatile-systolic area than control subjects (P < 0.05). Among subjects who completed the test, those with CFS had higher heart rate and smaller stroke volume (P < 0.05) than corresponding control subjects. When comparing those who had a positive test outcome in each group, CFS patients had higher heart rates and lower pulse pressure and pulsatile-systolic areas during the last 4 min before being returned to supine (P < 0.05). These data show that there are baseline differences in the cardiovascular profiles of CFS patients when compared with control subjects and that this profile is maintained during head-up tilt. However, the frequency of positive tilts and the haemodynamic adjustments made to this orthostatic challenge are not different between groups.

The study assessed peripheral sensory function and its relation to self-reported wartime exposures to potentially neurotoxic substances in Gulf War veterans with chronic fatigue syndrome (CFS). Male Gulf veterans fulfilling the 1994 CDC diagnostic criteria for CFS were compared with matched controls. Quantitative sensory testing was performed to establish thresholds of perception for the sense of light touch and radiant heat. The Devens survey was used to collect data on self-reported exposures to by-products of combustion and organophosphate compounds. Gulf veterans with CFS had elevated tactile but normal thermal thresholds compared with their controls. Sick veterans had greater rates of self-reported exposures and/or noxious side effects for all assessed toxicants. Interestingly, both Gulf veteran groups, including those reporting no symptoms, had impaired perception of light touch when compared with age-matched samples of non-Gulf war veteran men. The results of this study are consistent with a hypothesis that Gulf veterans with CFS have a subtle neurological deficit that might reflect underlying peripheral neuropathy. The association between this deficit and self-report of multiple potentially neurotoxic exposures suggests that war zone pollutants may be possible contributing factors. Copyright © 1999 John Wiley & Sons, Ltd.

This study was conducted to evaluate the immunological response to an exhaustive treadmill exercise test in 20 female chronic fatigue syndrome patients compared to 14 matched sedentary controls. Venipuncture was performed at baseline and 4 min, 1 hr, and 24 hr postexercise. White blood cells were labeled for monoclonal antibody combinations and were quantified by FACsan. Cytokines were assayed utilizing quantitative RT/PCR. No group difference was seen in \(\dot VO_{2_{peak} } \) (28.6 ± 1.6 vs 30.9 ± 1.2 ml · kg−1 · min−1; P > 0.05). However, 24 hr after exercise the patients' fatigue levels were significantly increased (P < 0.05). The counts of WBC, CD3+CD8+ cells, CD3+CD4+ cells, T cells, B cells, natural killer cells, and IFN-γ changed across time (P's < 0.01). No group differences were seen for any of the immune variables at baseline or after exercise (P's > 0.05). The immune response of chronic fatigue syndrome patients to exhaustive exercise is not significantly different from that of healthy nonphysically active controls.

412 The purpose of this study was to identify, by utilizing NIRS, the point at which there is a rapid rate of muscle deoxygenation during a graded exercise test to exhaustion (GXT). A second purpose was to compare the VO2 at the NIRS threshold to the VO2 values obtained at the blood lactate (LT) and gas exchange (GET) thresholds. The GXT was performed on a cycle ergometer by 15 healthy subjects (5 men and 10 women) pedaling at 60 rpms while the workload was increased 30 W every 3 minutes. Gas exchange and NIRS data were collected continuously. Blood lactate concentration was determined at the end of each stage by a finger stick protocol. A V-slope method was used to determine GET. The NIRS measurements were made in the vastus lateralis and the NIRS threshold was defined by the highest VO2 attained before a rapid muscle deoxygenation occurred. Each threshold was determined by two researchers who were blinded as to subject identity and the other thresholds. During the GXT all subjects obtained a RER > 1.1 and the mean VO2peak was 33.2 ml/kg/min. The percentages of VO2peak at which the thresholds occurred were 34.5, 36.1, and 48.2 for the NIRS threshold, LT, and GET, respectively. Significant relationships (Ps<.05) were seen when the VO2 at LT (r2=0.96) or at GET (r2=0.68). We concluded that during a GXT a muscle deoxygenation threshold can be detected using NIRS which will be highly predictive of the blood lactate threshold determined by a more invasive method.

The purpose of this study was to determine whether Gulf War Illness (GWI) can be explained by the presence of psychiatric disorders as assessed by DSM-III-R. To reduce the heterogeneity amongst Persian Gulf War veterans with GWI (PGV-F), only those were studied who presented with severe fatigue as a major complaint and also fulfilled clinical case definitions for Chronic Fatigue Syndrome, Idiopathic Chronic Fatigue, and/or Multiple Chemical Sensitivity. A total of 95 Registry PGVs were examined; 53 presented with GWI and 42 did not report any post-war health problems (PGV-H). All subjects were assessed for the presence of DSM-III-R Axis I psychiatric disorders. Compared to PGV-Hs, 49% of PGV-Fs had similar post-war psychiatric profiles: either no, or only one, psychiatric disorder was diagnosed. Psychiatric profiles of the remaining 51% of PGV-Fs were significantly different from PGV-Hs in that most of these veterans suffered from multiple post-war psychiatric diagnoses. The presence of psychiatric disorders as assessed by DSM-III-R criteria cannot explain symptoms of Gulf War Illness among all Persian Gulf veterans with severe fatiguing illness.

In research involving the cold pressor test, a tacit presumption is often made that reporting pain during stimulation is not in itself reactive. This study examined whether, for the foot and forehead cold pressor tests, activities involved in reporting pain may affect (a) the evoked pattern of cardiovascular response, and (b) the magnitude of self-perceived pain. In 40 normotensive college men, increases in systolic blood pressure were greater during test sessions that included verbal ratings of pain, as compared to sessions in which pain was not reported. In contrast to its effect on physiological activation, reporting pain did not significantly alter the participant’s perception of the painfulness of the test, on recollection shortly after the test. We conclude, therefore, that reporting pain during the cold pressor test may impose significant additional demands on the cardiovascular system, but it docs not interfere significantly with the processing of nociceptive information.