The Borg Scale as an Important Tool of Self-Monitoring and Self-Regulation of Exercise Prescription in Heart Failure Patients During Hydrotherapy - A Randomized Blinded Controlled Trial

Background: The Borg Scale may be a useful tool for heart failure patients to self-monitor and self-regulate exercise on land or in water (hydrotherapy) by maintaining the heart rate (HR) between the anaerobic threshold and respiratory compensation point. Methods and Results: Patients performed a cardiopulmonary exercise test to determine their anaerobic threshold/respiratory compensation points. The percentage of the mean HR during the exercise session in relation to the anaerobic threshold HR (%EHR-AT), in relation to the respiratory compensation point (%EHR-RCP), in relation to the peak HR by the exercise test (%EHR-Peak) and in relation to the maximum predicted HR (%EHR-Predicted) was calculated. Next, patients were randomized into the land or water exercise group. One blinded investigator instructed the patients in each group to exercise at a level between ""relatively easy and slightly tiring"". The mean HR throughout the 30-min exercise session was recorded. The %EHR-AT and %EHR-Predicted did not differ between the land and water exercisegroups, but they differed in the %EHR-RCP (95 +/- 7 to 86 +/- 7. P<0.001) and in the %EHR-Peak (85 +/- 8 to 78 +/- 9, P=0.007). Conclusions: Exercise guided by the Borg scale maintains the patient's HR between the anaerobic threshold and respiratory compensation point (ie, in the exercise training zone). (Circ J 2009; 73: 1871-1876)

Exercise training associated with diet improves heart rate recovery and cardiac autonomic nervous system activity in obese children

The purpose of this study was to test the hypotheses that in obese children: 1) hypocaloric diet (D) improves both heart rate recovery at 1 min (Delta HRR1) cfter an exercise test, and cardiac autonomic nervous system activity (CANSA) in obese children; 2) Diet and exercise training (DET) combined leads to greater improvement in both Delta HRR1 after an exercise test and in CANSA, than D alone. Moreover, we examined the relationships among Delta HRR1, CANSA, cardiorespiratory fitness and anthropometric variables (AV) in obese children submitted to D and to DET. 33 obese children (10 +/- 0.2 years; body mass index (BMI) >95(th) percentile) were divided into 2 groups: D (n = 15; BMI = 31 +/- 1 kg/m(2)) and DET (n = 18; 29 +/- 1 kg/m(2)). All children performed a maximal cardiopulmonary exercise test on a treadmill. The Delta HRR1 was defined as the difference between heart rate at peak and at 1-min post-exercise. CANSA was assessed using power spectral analysis of heart rate variability at rest. The sympathovagal balance (low frequency and high frequency ratio, LF/HF) was measured. After interventions, all obese children showed reduced body weight (P < 0.05). The D group did not improve in terms of peak VO(2), Delta HRR1 or LF/HF ratio (P > 0.05). In contrast, the DET group showed increased peak VO(2) (P = 0.01) and improved Delta HRR1 (Delta HRR1 = 37.3 +/- 2.6; P = 0.01) and LF/HF ratio (P = 0.001). The DET group demonstrated significant relationships among Delta HRR1, peak VO(2) and CANSA (P < 0.05). In conclusion, DET, in contrast to D, promoted improved Delta HRR1 and CANSA in obese children, suggesting a positive influence of increased levels of cardiorespiratory fitness by exercise training on cardiac autonomic activity.

Influence of angiotensinogen and angiotensin-converting enzyme polymorphisms on cardiac hypertrophy and improvement on maximal aerobic capacity caused by exercise training

Background The allele threonine (T) of the angiotensinogen has been associated with ventricular hypertrophy in hypertensive patients and soccer players. However, the long-term effect of physical exercise in healthy athletes carrying the T allele remains unknown. We investigated the influence of methionine M or T allele of the angiotensinogen and D or I allele of the angiotensin-converting enzyme on left-ventricular mass index (LVMI) and maximal aerobic capacity in young healthy individuals after long-term physical exercise training. Design Prospective clinical trial. Methods Eighty-three policemen aged between 20 and 35 years (mean +/- SD 26 +/- 4.5 years) were genotyped for the M235T gene angiotensinogen polymorphism (TT, n=25; MM/MT, n=58) and angiotensin-converting enzyme gene insertion/deletion (I/D) polymorphism (11, n=18; DD/DI, n=65). Left-ventricular morphology was evaluated by echocardiography and maximal aerobic capacity (VO(2peak)) by cardiopulmonary exercise test before and after 17 weeks of exercise training (50-80% VO(2peak)). Results Baseline VO(2peak) and LVMI were similar between TT and MM/MT groups, and II and DD/DI groups. Exercise training increased significantly and similarly VO(2peak) in homozygous TT and MM/MT individuals, and homozygous II and DD/DI individuals. In addition, exercise training increased significantly LVMI in TT and MM/MT individuals (76.5 +/- 3 vs. 86.7 +/- 4, P=0.00001 and 76.2 +/- 2 vs. 81.4 +/- 2, P=0.00001, respectively), and II and DD/DI individuals (777 +/- 4 vs. 81.5 +/- 4, P=0.0001 and 76 +/- 2 vs. 83.5 +/- 2, P=0.0001, respectively). However, LVMI I in TT individuals was significantly greater than in MM/MT individuals (P=0.04). LVMI was not different between 11 and DD/DI individuals. Conclusion Left-ventricular hypertrophy caused by exercise training is exacerbated in homozygous TT individuals with angiotensinogen polymorphism. Eur J Cardiovasc Prev Rehabil 16:487-492 (C) 2009 The European Society of Cardiology

The Carvedilol`s Beta-Blockade in Heart Failure and Exercise Training`s Sympathetic Blockade in Healthy Athletes during the Rest and Peak Effort

In recent years, beta-blocker therapy has become a primary pharmacologic intervention in patients with heart failure by blocking the sympathetic activity. To compare the exercise training`s sympathetic blockade in healthy subjects (athletes) and the carvedilol`s sympathetic blockade in sedentary heart failure patients by the evaluation of the heart rate dynamic during an exercise test. A total of 26 optimized and 49 nonoptimized heart failure patients in a stable condition (for, at least, 3 months), 15 healthy athletes and 17 sedentary healthy subjects were recruited to perform a cardiopulmonary exercise test. The heart rate dynamic (rest, reserve, peak and the peak heart rate in relation to the maximum predicted for age) was analyzed and compared between the four groups. The heart rate reserve was the same between optimized (48 +/- 15) and nonoptimized (49 +/- 18) heart failure patients (P < 0.0001). The athletes (188 +/- 9) showed a larger heart rate reserve compared to sedentary healthy subjects (92 +/- 10, P < 0.0001). Athletes and healthy sedentary reached the maximum age-predicted heart ratefor their age, but none of the heart failure patients did. The carvedilol`s sympathetic blockade occurred during the rest and during the peak effort in the same proportion, but the exercise training`s sympathetic blockade in healthy subjects occurred mainly in the rest.

Correlation between CD34(+) and exercise capacity, functional class, quality of life and norepinephrine in heart failure patients

Background: A previous study associated CD34(+) levels with NYHA functional class in heart failure patients. The aim of this study was to correlate CD34(+) levels to exercise capacity, functional class, quality of life and norepinephrine in heart failure patients. Methods: Twenty three sedentary patients (52 +/- 7 years, 78% male) answered the Minnesota Living with Heart Failure Questionnaire and rested for 20 minutes before an investigator collect a blood sample. After this, patients performed a cardiopulmonary exercise test to determine the heart rate at anaerobic and ventilatory threshold and oxygen consumption at peak effort, at anaerobic and ventilatory threshold. One other blood sample was collected during the peak effort to investigate the norepinephrine and CD34(+) levels. Results: Rest percentage of CD34(+) did not show correlation with: left ventricle ejection fraction (r = 0.03, p = 0.888), peakVO(2) (r = 0.32, p = 0.13), VO(2) at anaerobic threshold (VO(2)AT) (r = 0.03, p = 0.86), VO(2) at ventilatory threshold (VO(2)VT) (r = 0.36, p = 0.08), NYHA functional class (r = -0.2, p = 0.35), quality of life (Minnesota) (r = -0.17, p = 0.42). CD34(+) did not show correlation, either, with: peak VO(2) (r = 0.38, p = 0.06), VO(2)AT (r = 0.09, p = 0.65), VO(2)VT (r = 0.43, p = 0.4), NYHA functional class (r = -0.13, p = 0.54), quality of life (r = 0.00, p = 0.99). Conclusions: CD34(+) levels did not correlate with exercise capacity, functional class, quality of life and norepinephrine. Percentage of CD34(+) levels did not increase during the cardiopulmonary exercise test in heart failure patients. (Cardiol J 2009; 16, 5: 426-431)

VALIDATION OF THE LONDON CHEST ACTIVITY OF DAILY LIVING SCALE IN PATIENTS WITH HEART FAILURE

Background: The Minnesota Living with Heart Failure Questionnaire (MLHFQ) is a well-validated, commonly-used tool to assess quality of life in patients with heart failure. However, it lacks specific information concerning breathlessness during daily activities. Objective: To determine the validity of the London Chest Activity of Daily Living (LCADL) scale for use in patients with heart failure. Methods: Forty-seven patients with heart failure (57% males, mean age 50 years (standard deviation 9), mean left ventricle ejection fraction 29% (SD 6), New York Heart Association (NYHA) functional class I-III) were included. All subjects first performed a cardiopulmonary exercise test and then responded to the LCADL and the MLHFQ, with guidance from the same investigator. The re-test for the LCADL was applied one week later. Results: LCADL was correlated with MLHFQ (r=0.88; p < 0.0001). LCADL and MLHFQ were also correlated with exercise capacity (r=-0.75 and r=-0.73, respectively; both p < 0.0001). The LCADL was shown to be reproducible (r(i)=0.98). There was a significant difference (p < 0.05) in the LCADL scores between NYHA functional classes I and II, as well as classes I and III, hut not between classes II and III. Conclusion: The LCADL was shown to be a valid measurement of dyspnoea during daily activities in patients with heart failure. This scale could be an additional useful tool for the assessment of patients` dyspnoea during activities of daily living.

Physical activity profile in heart failure patients from a Brazilian tertiary cardiology hospital

Background: Physical activity (PA) has proven benefits in the primary prevention of heart diseases such as heart failure (HF). Although it is well known, HF PA habits and physicians` advice have been poorly described. The aim of this study was to investigate if physicians were advising HF patients to exercise and to quantify patients` exercise profiles in a complex cardiology hospital. Methods: All 131 HF patients (80 male, average age 53 +/- 10 years, NYHA class I-V, left ventricular ejection fraction 35 +/- 11%, 35 ischemic, 35 idiopatic , 32 hypertensive and 29 with Chagas disease) went to the hospital for a HF routine check-up. On this occasion, after seeing the physician, we asked the patients if the physician had advised them about PA. Then, we asked them to fill in the international physical activity questionnaire (IPQA) Short Form to classify their PA level. Results: Our data showed a significant difference between patients who had received any kind of PA advice from physicians (36%) and those who had not (64%, p<0.0001). Using the IPAQ criteria, of the 36% of patients who had received advice, 12.4% were classified as low and 23.6% as moderate. Of the 64% of patients who did not receive advice, 26.8% were classified as lowand 37.2% as moderate. Etiology (except Chagas), functional class, ejection fraction, sex and age did not influence the PA profile. Conclusions: Physicians at a tertiary cardiology hospital were not giving patients satisfactory advice as to PA. Our data supports the need to strengthen exercise encouragement by physicians and for complementary studies on this area. (Cardiol J 2010; 17, 2: 143-148)

Aerobic training abolishes ambulatory blood pressure increase induced by estrogen therapy: A double blind randomized clinical trial

Emerging data reveal that oral estrogen therapy can increase clinic blood pressure (BP) in postmenopausal women; however, it is important to establish its effects on ambulatory BP, which is a better predictor for target-organ damage. Besides estrogen therapy, aerobic training is widely recommended for post-menopausal women, and it can decrease ambulatory BP levels. This study was designed to evaluate the effect of aerobic training and estrogen therapy on the ambulatory BP of post-menopausal women. Forty seven healthy hysterectomized women were randomly divided (in a double-blind manner) into 4 groups: placebo-control (PLA-CO = 12), estrogen therapy-control (ET-CO = 14), placebo-aerobic training (PLA-AT = 12), and estrogen therapy-aerobic training (ET-AT = 09). The ET groups received estradiol valerate (1 mg/day) and the AT groups performed cycle ergometer, 3x/week at moderate intensity. Hormonal status (blood analysis), maximal cardiopulmonary exercise test (VO(2) peak) and ambulatory BP (24-h, daytime and nighttime) was evaluated before and 6 months after interventions. A significant increase in VO(2) peak was observed only in women who participated in aerobic training groups (+4.6 +/- 1.0 ml kg(-1) min(-1), P=0.00). Follicle-stimulating hormone was a significant decreased in the ET groups (-18.65 +/- 5.19 pg/ml, P=0.00), and it was accompanied by an increase in circulating estrogen (56.1 +/- 6.6 pg/ml). A significant increase was observed in the ET groups for daytime (P=0.01) and nighttime systolic BP (P=0.01), as well as nighttime diastolic BP (P = 0.02). However, daytime diastolic BP was increased only in the ET-CO group (+3.4 +/- 1.2 mmHg, P=0.04), and did not change in any other groups. No significant effect was found in ambulatory heart rate. In conclusion, aerobic training abolished the increase of daytime ambulatory BP induced by estrogen therapy in hysterectomized, healthy, normotensive and postmenopausal women. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Effects of proportional assisted ventilation on exercise performance in idiopathic pulmonary fibrosis patients

Background: Patients with idiopathic pulmonary fibrosis (IPF) present an important ventilatory (imitation reducing their exercise capacity. Non-invasive ventilatory support has been shown to improve exercise capacity in patients with obstructive diseases; however, its effect on IPF patients remains unknown. Objective: The present study assessed the effect of ventilatory support using proportional, assist ventilation (PAV) on exercise capacity in patients with IPF. Methods: Ten patients (61.2 +/- 9.2 year-old) were submitted to a cardiopulmonary exercise testing, plethysmography and three submaximal. exercise tests (60% of maximum load): without ventilatory support, with continuous positive airway pressure (CPAP) and PAV. Submaximal tests were performed randomly and exercise capacity, cardiovascular and ventilatory response as well as breathlessness subjective perception were evaluated. Lactate plasmatic levels were obtained before and after submaximal. exercise. Results: Our data show that patients presented a limited exercise capacity (9.7 +/- 3.8 mL O(2)/kg/min). Submaximal. test was increased in patients with PAV compared with CPAP and without ventilatory support (respectively, 11.1 +/- 8.8 min, 5.6 +/- 4.7 and 4.5 +/- 3.8 min; p < 0.05). An improved arterial oxygenation and lower subjective perception to effort was also observed in patients with IPF when exercise was performed with PAV (p < 0.05). IPF patients performing submaximal exercise with PAV also presented a lower heart rate during exercise, although systolic and diastolic pressures were not different among submaximal tests. Our results suggest that PAV can increase exercise tolerance and decrease dyspnoea and cardiac effort in patients with idiopathic pulmonary fibrosis. (C) 2009 Elsevier Ltd. All rights reserved.

Creatine supplementation spares muscle glycogen during high intensity intermittent exercise in rats

Background: The effects of creatine (CR) supplementation on glycogen content are still debatable. Thus, due to the current lack of clarity, we investigated the effects of CR supplementation on muscle glycogen content after high intensity intermittent exercise in rats. Methods: First, the animals were submitted to a high intensity intermittent maximal swimming exercise protocol to ensure that CR-supplementation was able to delay fatigue ( experiment 1). Then, the CR-mediated glycogen sparing effect was examined using a high intensity intermittent sub-maximal exercise test ( fixed number of bouts; six bouts of 30-second duration interspersed by two-minute rest interval) ( experiment 2). For both experiments, male Wistar rats were given either CR supplementation or placebo (Pl) for 5 days. Results: As expected, CR-supplemented animals were able to exercise for a significant higher number of bouts than Pl. Experiment 2 revealed a higher gastrocnemius glycogen content for the CR vs. the Pl group (33.59%). Additionally, CR animals presented lower blood lactate concentrations throughout the intermittent exercise bouts compared to Pl. No difference was found between groups in soleus glycogen content. Conclusion: The major finding of this study is that CR supplementation was able to spare muscle glycogen during a high intensity intermittent exercise in rats.

The beneficial effects of exercise in rodents are preserved after detraining: a phenomenon unrelated to GLUT4 expression

Background: Although exercise training has well-known cardiorespiratory and metabolic benefits, low compliance with exercise training programs is a fact, and the harmful effects of physical detraining regarding these adaptations usually go unnoticed. We investigated the effects of exercise detraining on blood pressure, insulin sensitivity, and GLUT4 expression in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). Methods: Studied animals were randomized into sedentary, trained (treadmill running/5 days a week, 60 min/day for 10 weeks), 1 week of detraining, and 2 weeks of detraining. Blood pressure (tail-cuff system), insulin sensitivity (kITT), and GLUT4 (Western blot) in heart, gastrocnemius and white fat tissue were measured. Results: Exercise training reduced blood pressure (19%), improved insulin sensitivity (24%), and increased GLUT4 in the heart (+34%); gastrocnemius (+36%) and fat (+22%) in SHR. In WKY no change in either blood pressure or insulin sensitivity were observed, but there was an increase in GLUT4 in the heart (+25%), gastrocnemius (+45%) and fat (+36%) induced by training. Both periods of detraining did not induce any change in neither blood pressure nor insulin sensitivity in SHR and WKY. One-week detraining reduced GLUT4 in SHR (heart: -28%; fat: -23%) and WKY (heart: -19%; fat: -22%); GLUT4 in the gastrocnemius was reduced after a 2-week detraining (SHR: -35%; WKY: -25%). There was a positive correlation between GLUT4 (gastrocnemius) and the maximal velocity in the exercise test (r = 0.60, p = 0.004). Conclusions: The study findings show that in detraining, despite reversion of the enhanced GLUT4 expression, cardiorespiratory and metabolic beneficial effects of exercise are preserved.

Aerobic exercise training improves skeletal muscle function and Ca(2+) handling-related protein expression in sympathetic hyperactivity-induced heart failure

Bueno CR Jr, Ferreira JC, Pereira MG, Bacurau AV, Brum PC. Aerobic exercise training improves skeletal muscle function and Ca(2+) handling-related protein expression in sympathetic hyperactivity-induced heart failure. J Appl Physiol 109: 702-709, 2010. First published July 1, 2010; doi: 10.1152/japplphysiol.00281.2010.-The cellular mechanisms of positive effects associated with aerobic exercise training on overall intrinsic skeletal muscle changes in heart failure (HF) remain unclear. We investigated potential Ca(2+) abnormalities in skeletal muscles comprising different fiber compositions and investigated whether aerobic exercise training would improve muscle function in a genetic model of sympathetic hyperactivity-induced HF. A cohort of male 5-mo-old wild-type (WT) and congenic alpha(2A)/alpha(2C) adrenoceptor knockout (ARKO) mice in a C57BL/6J genetic background were randomly assigned into untrained and trained groups. Exercise training consisted of a 8-wk running session of 60 min, 5 days/wk (from 5 to 7 mo of age). After completion of the exercise training protocol, exercise tolerance was determined by graded treadmill exercise test, muscle function test by Rotarod, ambulation and resistance to inclination tests, cardiac function by echocardiography, and Ca(2+) handling-related protein expression by Western blot. alpha(2A)/alpha(2C)ARKO mice displayed decreased ventricular function, exercise intolerance, and muscle weakness paralleled by decreased expression of sarcoplasmic Ca(2+) release-related proteins [alpha(1)-, alpha(2)-, and beta(1)-subunits of dihydropyridine receptor (DHPR) and ryanodine receptor (RyR)] and Ca(2+) reuptake-related proteins [sarco(endo) plasmic reticulum Ca(2+)-ATPase (SERCA) 1/2 and Na(+)/Ca(2+) exchanger (NCX)] in soleus and plantaris. Aerobic exercise training significantly improved exercise tolerance and muscle function and reestablished the expression of proteins involved in sarcoplasmic Ca(2+) handling toward WT levels. We provide evidence that Ca(2+) handling-related protein expression is decreased in this HF model and that exercise training improves skeletal muscle function associated with changes in the net balance of skeletal muscle Ca(2+) handling proteins.

Predicting MAOD using only a supramaximal exhaustive test

The objective of this study was to propose an alternative method (MAOD(ALT)) to estimate the maximal accumulated oxygen deficit (MAOD) using only one supramaximal exhaustive test. Nine participants performed the following tests: (a) a maximal incremental exercise test, (b) six submaximal constant workload tests, and (c) a supramaximal constant workload test. Traditional MAOD was determined by calculating the difference between predicted O(2) demand and accumulated O(2) uptake during the supramaximal test. MAOD(ALT) was established by summing the fast component of excess post-exercise oxygen consumption and the O(2) equivalent for energy provided by blood lactate accumulation, both of which were measured during the supramaximal test. There was no significant difference between MAOD (2.82 +/- 0.45 L) and MAOD(ALT) (2.77 +/- 0.37 L) (p = 0.60). The correlation between MAOD and MAOD(ALT) was also high (r = 0.78; p = 0.014). These data indicate that the MAOD(ALT) can be used to estimate the MAOD.

Pain threshold is achieved at intensity above anaerobic threshold in patients with intermittent claudication

PURPOSE: Walking training is considered as the first treatment option for patients with peripheral arterial disease and intermittent claudication (IC). Walking exercise has been prescribed for these patients by relative intensity of peak oxygen uptake (VO(2)peak), ranging from 40% to 70% VO(2)peak, or pain threshold (PT). However, the relationship between these methods and anaerobic threshold (AT), which is considered one of the best metabolic markers for establishing training intensity, has not been analyzed. Thus, the aim of this study was to compare, in IC patients, the physiological responses at exercise intensities usually prescribed for training (% VO(2) peak or % PT) with the ones observed at AT. METHODS: Thirty-three IC patients performed maximal graded cardiopulmonary treadmill test to assess exercise tolerance. During the test, heart rate (HR), VO(2), and systolic blood pressure were measured and responses were analyzed at the following: 40% of VO(2)peak; 70% of VO(2)peak; AT; and PT. RESULTS: Heart rate and VO(2) at 40% and 70% of VO(2)peak were lower than those at AT (HR: -13 +/- 9% and -3 +/- 8%, P < .01, respectively; VO(2): -52 +/- 12% and -13 +/- 15%, P < .01, respectively). Conversely, HR and VO(2) at PT were slightly higher than those at AT (HR: +3 +/- 8%, P < .01; VO(2): + 6 +/- 15%, P = .04). None of the patients achieved the respiratory compensation point. CONCLUSION: Prescribing exercise for IC patients between 40% and 70% of VO(2)peak will induce a lower stimulus than that at AT, whereas prescribing exercise at PT will result in a stimulus above AT. Thus, prescribing exercise training for IC patients on the basis of PT will probably produce a greater metabolic stimulus, promoting better cardiovascular benefits.

Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion

Aim. It has been demonstrated that branched-chain amino acids (BCAA) transaminase activation occurs simultaneously with exercise-induced muscle glycogen reduction, suggesting that BCAA supplementation might play an energetic role in this condition. This study aimed to test whether BCAA supplementation enhances exercise capacity and lipid oxidation in glycogen-depleted subjects. Methods. Using a double-blind cross-over design, volunteers (N.=7) were randomly assigned to either the BCAA (300 mg . kg . day (-1)) or the placebo (maltodextrine) for 3 days. On the second day, subjects were submitted to an exercise-induced glycogen depletion protocol. They then performed an exhaustive exercise test on the third day, after which time to exhaustion, respiratory exchange ratio (RER), plasma glucose, free fatty acids (HA), blood ketones and lactate were determined. BCAA supplementation promoted a greater resistance to fatigue when compared to the placebo (+17.2%). Moreover, subjects supplemented with BCAA showed reduced RER and higher plasma glucose levels during the exhaustive exercise test. Results. No significant differences appeared in FFA, blood ketones and lactate concentrations. Conclusion. In conclusion, BCAA supplementation increases resistance to fatigue and enhances lipid oxidation during exercise in glycogen-depleted subjects.