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PubMed2000

Chronic exercise training improves ACh-induced vasorelaxation in pulmonary arteries of pigs.

We hypothesized that exercise training would lead to enhanced endothelium-dependent vasodilation in porcine pulmonary arteries. Pulmonary artery rings (2- to 3-mm OD) were obtained from female Yucatan miniature swine with surgically induced coronary artery occlusion (ameroid occluder). Exercise training was performed for 16 wk, and vasomotor responses were studied by using standard isometric techniques. Contractile responses to 80 mM KCl, isosmotic KCl (10-100 mM), and norepinephrine (10(-8) to 10(-4) M) did not differ between sedentary (Sed) and exercise-trained (Ex) pigs. Relaxation was assessed to endothelium-dependent and endothelium-independent vasodilators after norepinephrine contraction. Pulmonary arteries of Ex pigs exhibited greater maximal relaxation to ACh (61.9 +/- 3.5%) than did those of Sed pigs (52.3 +/- 3.9%; P < 0.05). Endothelium-independent relaxation to sodium nitroprusside did not differ. Inhibition of nitric oxide synthase significantly decreased acetylcholine-induced relaxation, with greater inhibition in arteries from Ex pigs (P < 0.05). Inhibition of cyclooxygenase enhanced relaxation to acetylcholine in arteries from Sed pigs. We conclude that exercise training enhances endothelium-dependent (ACh-mediated) vasorelaxation in pulmonary arteries by mechanisms of increased reliance on nitric oxide and reduced production of a prostanoid constrictor.

Acetylcholine↗

PubMed1990

Skeletal muscle oxidative capacity, antioxidant enzymes, and exercise training.

The purposes of this study were to determine whether exercise training induces increases in skeletal muscle antioxidant enzymes and to further characterize the relationship between oxidative capacity and antioxidant enzyme levels in skeletal muscle. Male Sprague-Dawley rats were exercise trained (ET) on a treadmill 2 h/day at 32 m/min (8% incline) 5 days/wk or were cage confined (sedentary control, S) for 12 wk. In both S and ET rats, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) activities were directly correlated with the percentages of oxidative fibers in the six skeletal muscle samples studied. Muscles of ET rats had increased oxidative capacity and increased GPX activity compared with the same muscles of S rats. However, SOD activities were not different between ET and S rats, but CAT activities were lower in skeletal muscles of ET rats than in S rats. Exposure to 60 min of ischemia and 60 min of reperfusion (I/R) resulted in decreased GPX and increased CAT activities but had little or no effect on SOD activities in muscles from both S and ET rats. The I/R-induced increase in CAT activity was greater in muscles of ET than in muscles of S rats. Xanthine oxidase (XO), xanthine dehydrogenase (XD), and XO + XD activities after I/R were not related to muscle oxidative capacity and were similar in muscles of ET and S rats. It is concluded that although antioxidant enzyme activities are related to skeletal muscle oxidative capacity, the effects of exercise training on antioxidant enzymes in skeletal muscle cannot be predicted by measured changes in oxidative capacity.

Animals↗

PubMed2000

Cardiovascular exercise and wellness. Exercise training for cardiac rehabilitation patients: meeting the challenges of the millennium.

Exercise training for cardiac rehabilitation has evolved over the past decades in response to a growing knowledge base in exercise physiology, an expanding understanding to the knowledge base of coronary disease, and a change in the patients presenting for cardiac rehabilitation. The patient population has changed from a post myocardial infarction patient group, to patients who have had coronary artery revascularization (coronary artery bypass surgery or percutaneous transluminal coronary angioplasty) with the implantation of intraarterial stents. Program goals have evolved from enhancing endurance fitness in deconditioned patients to initiating the long-term adoption of an active exercising lifestyle with the use of strength training to complement endurance training. An increased understanding of behavioral issues in the adoption of an active lifestyle will influence the evolution of cardiac rehabilitation exercise training. During the next several years, it is anticipated that the patient population will change to include patients with significant left ventricular systolic dysfunction and congestive heart failure. The exercise training programs will then further evolve to reflect the successful exercise training formats utilized in the multicenter trials of exercise training for patients with congestive heart failure. (c) 2000 by CHF, Inc.

Journal Article↗

PubMed2002

Exercise training increases arterial compliance in patients with congestive heart failure.

Systemic arterial compliance (SAC) makes an important contribution to cardiac afterload, and thus is a significant determinant of left ventricular work. Previous studies have suggested that arterial compliance may be reduced in patients with congestive heart failure (CHF), and that SAC is increased after a 4-week exercise training programme in healthy, sedentary individuals. The present study aimed to investigate the effects of an 8-week exercise training programme on arterial mechanical properties, left ventricular performance and quality of life in CHF patients. A total of 21 patients with NYHA class II or III CHF (mean+/-S.D. age 55+/-13 years) were randomly allocated to either an 8-week exercise training group or a "usual lifestyle" control group. SAC, as determined non-invasively using applanation tonometry and Doppler aortic velocimetry, increased from 0.57+/-0.11 to 0.77+/-0.14 arbitrary compliance units (mean+/-S.E.M.; P=0.01) in the exercise group, while no change occurred in the control group. Left ventricular structure and function was assessed by echocardiography, and these parameters were unchanged over the 8-week study period. Exercise training significantly increased exercise capacity, measured by a 6-min walking test (474+/-27 to 547+/-34 m; P=0.008). Quality of life, as assessed using the Minnesota Living with Heart Failure Evaluation, demonstrated a decrease in heart failure symptoms from 46+/-7 to 24+/-5 units (P=0.01) following the exercise training programme. These data show that exercise training improves SAC in patients with CHF. The accompanying improvement in exercise capacity may be due, in part, to an improvement in arterial function.

Adolescent↗

PubMed2004

Effects of exercise training and detraining on oxidized low-density lipoprotein-potentiated platelet function in men.

OBJECTIVE: To investigate how exercise training and detraining affect oxidized low-density lipoprotein (Ox-LDL)-potentiated platelet function in men. DESIGN: Cohort study. SETTING: Department of physical medicine and rehabilitation. PARTICIPANTS: Ten sedentary men (mean age +/- standard error of the mean, 21.6+/-0.2 y) who did not engage in any regular physical activity for at least 1 year before the study. INTERVENTIONS: Subjects cycled on an ergometer at about 50% of maximal oxygen consumption for 30 minutes daily, 5 days a week, for 8 weeks, then detrained for 12 weeks. MAIN OUTCOME MEASURES: During the experimental period, blood samples from the subjects were collected before and immediately after a progressive exercise test (ie, strenuous, acute exercise) every 4 weeks. The following measurements were taken when the subjects were at rest and immediately after exercise: plasma lipid profile, plasma Ox-LDL level, and platelet aggregation and intracellular calcium concentration ([Ca2+]i) elevation induced by adenosine disphosphate (ADP) alone or simultaneous ADP and Ox-LDL addition. RESULTS: Analytical results indicated that: (1) plasma total cholesterol and LDL levels were reduced after exercise training from 151+/-7 mg/dL and 58+/-2 mg/dL to 133+/-6 mg/dL and 46+/-2 mg/dL (P<.05), respectively, whereas the plasma Ox-LDL level remained unchanged; (2) platelet aggregation and [Ca2+]i elevation promoted by 100 microg/mL of Ox-LDL were significantly increased from 70%+/-5% and 91%+/-7% of resting level to 108%+/-4% and 125%+/-3% after strenuous, acute exercise (P<.05); (3) exercise training decreased resting and postexercise 100 microg/mL Ox-LDL-potentiated platelet aggregation (ie, 31%+/-4% and 82%+/-4%, respectively; P<.05) and [Ca2+]i elevation (ie, 35%+/-6% and 71%+/-4%, respectively; P<.05); (4) detraining reversed the training effects on lipid profile and platelet function; and (5) treating the platelet with L-arginine-inhibited Ox-LDL-potentiated platelet activation during the experimental period. CONCLUSIONS: Our results suggest that 8 weeks of exercise training decreased the plasma LDL level, but failed to influence production of plasma Ox-LDL. Importantly, resting and exercise-induced Ox-LDL-potentiated platelet activation was decreased by exercise training. However, this was reversed by detraining to the pretraining level.

Adenosine Diphosphate↗

PubMed2006

Effect of endurance exercise training on heart rate onset and heart rate recovery responses to submaximal exercise in animals susceptible to ventricular fibrillation.

Both a large heart rate (HR) increase at exercise onset and a slow heart rate (HR) recovery following the termination of exercise have been linked to an increased risk for ventricular fibrillation (VF) in patients with coronary artery disease. Endurance exercise training can alter cardiac autonomic regulation. Therefore, it is possible that this intervention could restore a more normal HR regulation in high-risk individuals. To test this hypothesis, HR and HR variability (HRV, 0.24- to 1.04-Hz frequency component; an index of cardiac vagal activity) responses to submaximal exercise were measured 30, 60, and 120 s after exercise onset and 30, 60, and 120 s following the termination of exercise in dogs with healed myocardial infarctions known to be susceptible (n = 19) to VF (induced by a 2-min coronary occlusion during the last minute of a submaximal exercise test). These studies were then repeated after either a 10-wk exercise program (treadmill running, n = 10) or an equivalent sedentary period (n = 9). After 10 wk, the response to exercise was not altered in the sedentary animals. In contrast, endurance exercise increased indexes of cardiac vagal activity such that HR at exercise onset was reduced (30 s after exercise onset: HR pretraining 179 +/- 8.4 vs. posttraining 151.4 +/- 6.6 beats/min; HRV pretraining 4.0 +/- 0.4 vs. posttraining 5.8 +/- 0.4 ln ms(2)), whereas HR recovery 30 s after the termination of exercise increased (HR pretraining 186 +/- 7.8 vs. posttraining 159.4 +/- 7.7 beats/min; HRV pretraining 2.4 +/- 0.3 vs. posttraining 4.0 +/- 0.6 ln ms(2)). Thus endurance exercise training restored a more normal HR regulation in dogs susceptible to VF.

Animals↗

PubMed1983

Pancreatic insulin response in relation to exercise training.

The present study was undertaken to measure the effects of exercise training on pancreatic insulin secretion in response to glucose and nonglucose stimuli. Wistar female rats with an initial body weight of approximately 180 g were divided into trained and sedentary groups. After a period of 10 weeks of training, glucose-, tolbutamide-, and arginine-tolerance tests were performed in vivo in both trained and untrained animals. The tests were done in nonanesthetized animals 40 h after the last exercise bout. It was found that exercise training leads to a diminution of plasma insulin levels after either glucose, tolbutamide, or arginine administration. These results present direct evidence that exercise training reduces plasma insulin response not only to glucose but also to nonglucidic secretagogues.

Animals↗

PubMedDate not supplied

Effect of prolonged intermittent hypoxia and exercise training on glucose tolerance and muscle GLUT4 protein expression in rats.

We compared the chronic effect of intermittent hypoxia and endurance training on the glucose tolerance and GLUT4 protein expression in rat skeletal muscle. Thirty-two Sprague-Dawley rats were matched for weight and assigned to one of the following four groups: control, endurance training, hypoxia, or hypoxia followed by endurance training. Hypoxic treatment consisted of breathing 14% O2 for 12 h/day under normobaric conditions, and the training protocol consisted of making animals swim 2 times for 3 h/day. At the end of the 3rd week, an oral glucose tolerance test (OGTT) was performed 16 h after treatments. At the end of the 4th week, GLUT4 protein, mRNA, and glycogen storage in skeletal muscle were determined. Endurance training significantly improved OGTT results. Glycogen content and GLUT4 protein expression in the plantaris and red gastrocnemius, but not in the soleus or white gastrocnemius muscles, were also elevated. Chronic intermittent hypoxia also improved OGTT results, but did not alter GLUT4 protein expression. Additionally, hypoxia followed by exercise training produced significant increases in GLUT4 protein and mRNA in a greater number of muscles compared to endurance training alone. Both exercise training and hypoxia significantly reduced body mass, and an additive effect of both treatments was found. In conclusion, chronic intermittent hypoxia improved glucose tolerance in the absence of increased GLUT4 protein expression. This treatment facilitated the exercise training effect on muscle GLUT4 expression and glycogen storage. These new findings open the possibility of utilizing intermittent hypoxia, with or without exercise training, for the prevention and clinical treatment of type 2 diabetes or insulin resistance.

Analysis of Variance↗

PubMed1990

Enhanced calcium uptake of cardiac sarcoplasmic reticulum in exercise-trained old rats.

To determine whether endurance exercise training initiated during senescence improves the slower calcium transport of cardiac sarcoplasmic reticulum in senescent rats, three groups of male Fischer 344 rats were used: sedentary mature (SM), 11-12 mo of age; sedentary old (SO), 23-24 mo of age; and exercised old (EO), 23-24 mo of age. The EO rats ran on a motor-driven treadmill 5 days/wk for 8-10 wk while two other groups remained sedentary. The contraction duration of isometrically contracting papillary muscle was prolonged in the SO rats compared with the SM group, resulting from both a longer time-to-peak tension and a longer half-relaxation time. Chronic exercise improved the papillary muscle contractile function of the EO group to that observed in the younger SM rats. More importantly, the exercise regime ameliorated the slower oxalate-supported, ATP-dependent calcium transport observed in the SO group so that the EO and SM groups were the same. In contrast, the calcium-activated myosin adenosinetriphosphatase activity, which was slower in the SO group, was not altered after exercise training, so that both senescent groups were slower than the SM rats. Thus the increased calcium transport by the cardiac sarcoplasmic reticulum may be one of the potential mechanisms underlying the improvement of myocardial performance with chronic exercise initiated during senescence.

Aging↗

PubMed1997

Exercise training enhances cardiac function in response to an afterload stress in older men.

This study was designed to characterize cardiac adaptations to endurance exercise training in older healthy men by evaluation of changes in left ventricular function in response to an afterload stress in the presence of cardiac muscarinic receptor blockade. Eight men 65 +/- 2 (SE) yr old underwent 9 mo of endurance exercise training. Maximal O2 uptake (V(O2 max)) was determined during treadmill exercise. Left ventricular function was assessed with two-dimensional echocardiography and pulsed Doppler transmitral flow velocity profile at baseline, after an intravenous bolus of atropine and during infusion of graded doses of phenylephrine. V(O2 max) was increased by 29% in response to training (28.9 +/- 1 to 37.3 +/- 1 ml x kg(-1) x min(-1)). Baseline end-diastolic diameter (EDD) was increased, with no change in left ventricular wall thickness-to-radius ratio, after training, suggestive of eccentric left ventricular hypertrophy. EDD, end-systolic dimension, and end-systolic wall stress (sigma(es)) increased similarly in response to phenylephrine before and after training. Fractional shortening (FS) decreased in response to phenylephrine before but not after training. When the changes in FS (delta FS) during phenylephrine infusion were plotted as a function of changes in sigma(es), delta FS were significantly higher after than before training (P = 0.003) at comparable increases in sigma(es), indicative of improved contractile function. This adaptive response was preload independent, because EDD did not differ between the trained and untrained states during phenylephrine infusion. Heart rate responses to phenylephrine were similar before and after training. Exercise training resulted in a higher (P = 0.028) early-to-late transmitral diastolic flow velocity ratio at virtually identical heart rates, suggestive of improved diastolic filling. The results suggest that endurance exercise training induces an enhancement of left ventricular systolic function in response to an afterload stress in older healthy men.

Aged↗

PubMed1998

Changes in core temperature and thermoeffector thresholds in exercise-trained rats.

Spontaneous running in a running wheel has emerged as an alternative method of exercise in small animals. The present study investigated how exercise training with a running wheel affects core temperature level and thermoeffector thresholds in rats. Female rats were allowed to run freely in the wheel for 6 months. Sedentary controls did not exercise during the same period. After the exercise training period, they were loosely restrained and their threshold core temperatures for tail skin vasodilation and cold-induced thermogenesis were determined by warming or cooling the animals by use of a chronically implanted intravenous thermode. Resting and threshold core temperatures of the exercise-trained rats were higher than those of the sedentary controls. The results suggest that in rat, exercise training with a running wheel shifts threshold temperatures for heat loss and heat production to high levels, which may result in a rise in core temperature level.

Animals↗

PubMed1991

The effects of moderate exercise training on psychological well-being and mood state in women.

The relationship between moderate exercise training (five 45 min sessions/week, brisk walking at 62 beta +/- 2% VO2max for 15 weeks, psychological well-being and mood state was investigated in a group of 35 sedentary, mildly obese women. A 2 (exercise (EX) (N = 18), and nonexercise (NEX) (N = 17) groups) x 3 (baseline, 6-week, 15-week testing sessions) factorial design was used with data analyzed using repeated measures ANOVA. Four psychological tests were administered: Daily Hassles Scale (DHS), General Well-being Schedule (GWB), Spielberger State Anxiety Inventory (S-Anxiety), and Profile of Mood States (POMS). The EX and NEX groups had significantly different patterns of change over time for GWB total scores [F(2,66) = 5.72, p = 0.005] and the GWB subscales 'energy level' and 'freedom from health concern or worry'. Scores for the EX group were elevated at both 6 and 15 weeks. General well-being total scores and subscale 'energy level' scores were significantly correlated with improvement in submaximal cardiorespiratory fitness (r = -0.41, p = 0.014; r = -0.40, p = 0.017, respectively). Exercise training also had a significant effect on frequency but not intensity of DHS scores, and S-Anxiety, with a significant decrease seen in the EX group at 6 weeks but not 15 weeks. Profile of Mood States scores were not significantly related to exercise training. These data support the results of other studies that have reported improvement in general psychological well-being with exercise training.

Adaptation, Psychological↗

PubMed1992

Exercise training increases glucose transporter content in skeletal muscles more efficiently from aged obese rats than young lean rats.

Glucose uptake in rat skeletal muscles decreases with age and obesity, but increases with chronic exercise training. The purpose of our study was to determine whether the GLUT4 content in several skeletal muscles from 1-mo-old young, lean rats and 12-mo-old aged, obese rats alters with exercise training. For exercise, a treadmill run of approximately 1 km/day was made for 4 wk by both groups of rats. The concentration of GLUT4 per protein in membrane fraction from several skeletal muscles was measured by immunoblotting. The amount of GLUT4 in the gastrocnemius and white quadriceps from aged rats slightly but significantly decreased to 73% and 78% of that from young rats, respectively. However, no significant difference in GLUT4 amount in the soleus, plantaris, and red quadriceps was observed between young and aged rats. The exercise training resulted in a larger increase in the amount of GLUT4 in each muscle from aged rats than in muscles from young rats. In aged rats, GLUT4 amount increased significantly with exercise training by 30, 33, 41, and 27% in the soleus, plantaris, gastrocnemius, and red quadriceps, respectively, compared with the sedentary controls. However, in young rats, exercise-induced increase of GLUT4 amount was significant only in the plantaris, and the increase was 17%. In exercised aged, obese rats, decreases of body weight, plasma triglyceride levels, and plasma free fatty acid were also observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

PubMed1998

Effects of exercise training on limb blood flow in patients with reduced ventricular function.

BACKGROUND: Among the factors that contribute to limiting exercise tolerance in chronic heart failure are reduced peripheral blood flow and impaired vasodilatory capacity. Exercise training improves vasodilatory capacity in normal subjects, but controlled studies of exercise training evaluating upper and lower limb blood flow rates have not been performed in patients with reduced ventricular function. Improved vasodilatory capacity could help explain how training increases exercise capacity in these patients. METHODS: Twenty patients (mean age 55 +/- 6 years) with reduced left ventricular function (mean ejection fraction 32% +/- 6%) after a myocardial infarction were randomized to a 2-month high-intensity residential rehabilitation program or to a control group and were monitored over the subsequent year. Both groups were treated according to current practice with angiotensin-converting enzyme inhibition therapy. Training began 1 month after myocardial infarction. Baseline and postischemic flow rates were measured by plethysmography in both the upper and lower limbs 1 month, 3 months, and 1 year after the infarction. Peak oxygen uptake (VO2) and cardiac output were measured before and after training, and peak VO2 was determined again after 1 year. RESULTS: After 2 months of training peak VO2 increased 25%, VO2 at the lactate threshold increased 40%, and maximal cardiac output increased from 12.1 +/- 1.6 L/min to 13.9 +/- 2.4 L/min in the exercise group (all p < 0.05), whereas no differences were observed in the control group. At the 1-year follow-up no further increases in peak VO2 were noted in either group, but the higher value persisted in the trained group. However, changes in limb flow rates were poorly related to changes in both peak VO2 and maximal cardiac output. Improvements in baseline and postischemic flow rates occurred mainly in the lower limbs and were observed in the two groups to a similar degree. CONCLUSION: Exercise training is highly effective in improving exercise capacity in patients with reduced ventricular function after myocardial infarction. These improvements parallel an increase in maximal cardiac output, but they are unrelated to vasodilatory capacity. In patients with reduced ventricular function after myocardial infarction, lower limb vasodilatory capacity improves gradually over the subsequent year, and these improvements occur irrespective of exercise training.

Adult↗

PubMed1998

Comparison of left ventricular function during interval versus steady-state exercise training in patients with chronic congestive heart failure.

This study sought to assess the safety of interval exercise training in patients with chronic congestive heart failure (CHF) with respect to left ventricular (LV) function. For effective rehabilitation in CHF, both aerobic capacity and muscle strength need to be improved. We have previously demonstrated in both coronary artery bypass surgery and patients with CHF that interval exercise training (IET) offers advantages over steady-state exercise training (SSET). However, because LV function during IET has not yet been studied, the safety of this method in CHF remains unclear. To assess LV function during IET and SSET, at the same average power output, 11 patients with stable CHF were compared with 9 stable coronary patients with minimal LV dysfunction (control group). Using first-pass radionuclide ventriculography, changes in LV function were assessed during work versus recovery phases, at temporally matched times between the fifth and sixteenth minute of IET and SSET. In CHF during IET, there were no significant variations in the parameters measured during work and/or recovery phases. During the course of both IET and SSET, there was a significant increase in LV ejection fraction (5 vs 4 U; p <0.05 each), accompanied by increased heart rate (6 vs 8 beats/min; p <0.05 each) and cardiac output (2.4 vs 1.8 L/min; p <0.01 and p <0.05). In CHF, the magnitude of change in LV ejection fraction during IET was similar to that seen in controls. Both LV ejection fraction and the clinical status in patients with CHF remained stable during IET. Because IET appears to be as safe as SSET with respect to LV function, IET can be recommended for exercise training in CHF to apply higher peripheral exercise stimuli and with no greater LV stress than during SSET.

Exercise Therapy↗

PubMed1984

Influence of exercise training on tissue chromium concentrations in the rat.

This study reports on the effects of exercise training on the chromium concentrations in the heart, liver, kidney, and gastrocnemius muscle of normal Sprague-Dawley rats. A pair-fed (to the trained rats' intake) and a preexperimental group were also studied in order to control food intake and to ascertain any age-related influence on tissue chromium levels, respectively. Four groups of animals were examined: exercise-trained, pair-fed, preexperimental, and sedentary control. Chromium determination was performed by flameless atomic absorption spectrophotometry. The results from this study show that exercise training increases while pair-feeding and normal aging both decrease chromium levels in tissues. It is suggested that the male Sprague-Dawley rat adapts to exercise training by enhancing tissue levels of chromium or by simply maintaining the high levels of the element found at a younger age.

Aging↗

PubMed1996

The effect of exercise training on cold tolerance in adult and old C57BL/6J mice.

In order to ascertain the effect of aging on cross-adaptation between exercise training and cold tolerance, we studied cold tolerance in adult and old C57BL/6J male mice before and after 6 weeks of an exercise regimen of moderate intensity. There were two age groups of 32 mice each, including 12-month-old (adult) and 24-month-old (aged) mice equally divided into control and exercise groups. The exercise consisted of daily runs on a treadmill (1 hr/day, 5 days/week) for 6 weeks, while the control mice spent the same time on a stationary treadmill. All mice were subjected to a cold stress test (3-hr partial restraint at 6 degrees C) prior to and following the designated regimen. The results revealed a statistically significant interaction between age and exercise training. In adult mice, exercise resulted in a reduction of cold-induced heat production and weakening of cold tolerance, while in aged mice, the opposite effect was observed; i.e., an increase in cold-induced heat production accompanied by greater cold tolerance. However, only the attenuating effect on cold tolerance of adults was statistically significant. The results of our experiments do not support the existence of cross-adaptation between exercise training and cold tolerance. They indicate, however, that exercise training affects the cold tolerance in adult and old mice through different physiological mechanisms.

Adaptation, Physiological↗

PubMed2005

Cognitive functions in severe congestive heart failure before and after an exercise training program.

BACKGROUND: Congestive heart failure is associated with cognitive impairment, particularly of attentional skills. We assessed, in a hypothesis-generating study, the effect of an exercise training program on cognitive functions among patients with severe congestive heart failure. METHODS: Patients with severe congestive heart failure (n=20; New York Heart Association functional class III; left ventricular ejection fraction < or =35%) were evaluated before and following a standardized and supervised exercise training program (x2/week for 18 weeks; exercise group), while 5 additional patients did not undergo an exercise training program (control group). A battery of cognitive tests was used to assess cognitive functions. Physical performance was assessed by the 6-min walk test and the modified Bruce exercise test, cardiac index and systemic vascular resistance using thoracic electrical bioimpedance, and cerebral vasomotor reactivity to hypercapnia by means of the breath-holding index using transcranial Doppler. RESULTS: Time of completion of the trail making A (105+/-116 to 75+/-52; p=0.02) and B (169+/-100 to 119+/-65; p=0.002) tests, and of the Stroop part A (40+/-13 to 37+/-13; p=0.04) was shorter in patients completing the exercise training program, but not in control patients, while the other neuropsychological measures remained unchanged in both groups. Cerebral vasomotor reactivity to hypercapnia remained diminished (breath-holding index 0.64+/-0.27 vs. 0.68+/-0.37) despite significant improvements in exercise capacity (6-min walk test 308+/-87 to 423+/-91 m, p<0.001; modified Bruce exercise test 5.6+/-3.8 to 9.8+/-3.4 min, p<0.001). CONCLUSIONS: Patients with severe congestive heart failure undergoing an exercise training program improve in some measures of cognitive functions that are limited to general attention and psychomotor speed. Based on these preliminary findings, further evaluations are designed within the framework of a larger controlled clinical trial.

Adult↗