Comparison of high- and low-intensity exercise training early after acute myocardial infarction

Effects of high-intensity interval training on health-related quality of life in chronic lymphocytic leukemia: A pilot study

INTRODUCTION

Chronic lymphocytic leukemia (CLL) is the most common incurable leukemia/lymphoma in the United States. Individuals with CLL are at risk for disability, frailty, and cancer-specific complications that negatively affect health-related quality of life (HRQOL). High-intensity interval training (HIIT) and resistance training (RT) are safe and feasible for individuals with chronic diseases and when combined, they may be beneficial for reducing cancer-related fatigue, symptom burden, and global quality of life. However, no studies have examined the impact of HIIT or RT on HRQOL in CLL. The purpose of this study was to investigate the effects of a 12-week HIIT and RT (HIIT+RT) intervention on HRQOL in adults with treatment naïve CLL.

MATERIALS AND METHODS

Changes in HRQOL was a secondary outcome in this pilot study. Individuals with CLL (63.9 ± 8.5 yrs) were non-randomly assigned to 12 weeks of HIIT+RT or a control group. The HIIT+RT protocol consisted of three 30-min sessions/week of HIIT and two sessions/week of RT. The control group maintained usual daily activities. We assessed pre and post HRQOL using the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) questionnaire with domains of physical (PWB), social (SWB), emotional (EWB), functional (FWB), and general (FACT-G) well-being as well as a lymphoma-specific subscale (LymS). We used a two-way mixed analysis of variance to assess changes in HRQOL. We calculated effect size (ES) using Cohen's d.

RESULTS

Fifteen participants (HIIT+RT: n = 9; Control: n = 6) completed the study and questionnaire. Scores for FWB improved following HIIT+RT (21.7 ± 3.4 to 23.9 ± 3.2; ES = 1.38) compared to controls (25.7 ± 2.2 to 25.7 ± 2.3). The HIIT+RT group experienced clinically meaningful improvements in total FACT-Lym, FWB, FACT-G, and LymS. The control group had clinically meaningful changes only in LymS.

DISCUSSION

The large effect sizes and clinically meaningful improvements associated with 12 weeks of HIIT+RT support the potential benefits of this type of exercise program for FWB, lymphoma-specific symptoms, and general well-being in CLL. A future randomized trial with an adequately powered sample size is needed to evaluate these findings.

TRIAL REGISTRATION

NCT04950452.

Cerebrovascular Function, Vascular Risk, and Lifestyle Patterns in Resistant Hypertension

BACKGROUND

Impaired cerebrovascular reactivity (CVR) and blunted cerebral hemodynamic recruitment are thought to be important mechanisms linking hypertension to cerebrovascular and cognitive outcomes. Few studies have examined cardiovascular or dietary correlates of CVR among hypertensives.

OBJECTIVE

To delineate associations between cardiometabolic risk, diet, and cerebrovascular functioning among individuals with resistant hypertension from the TRIUMPH trial (n = 140).

METHODS

CVR was assessed by examining changes in tissue oxygenation (tissue oxygenation index [TOI] and oxygenated hemoglobin [HBO2]) using functional near-infrared spectroscopy (fNIRS) during a breath holding test, a standardized CVR assessment to elicit a hypercapnic response. Participants also underwent fNIRS during three cognitive challenge tasks. Vascular function was assessed by measurement of brachial artery flow mediated dilation and hyperemic flow response. Cardiometabolic fitness was assessed from peak VO2 on an exercise treadmill test and body mass index. Dietary patterns were quantified using the DASH eating score. Cognitive function was assessed using a 45-minute test battery assessing Executive Function, Processing Speed, and Memory.

RESULTS

Greater levels fitness (B = 0.30, p = 0.011), DASH compliance (B = 0.19, p = 0.045), and lower obesity (B = -0.30, p = 0.004), associated with greater changes in TOI, whereas greater flow-mediated dilation (B = 0.19, p = 0.031) and lower stroke risk (B = -0.19, p = 0.049) associated with greater HBO2. Similar associations were found for cerebral hemodynamic recruitment, and associations between CVR and cognition were moderated by duration of hypertension.

CONCLUSION

Impaired CVR elevated cardiometabolic risk, obesity, vascular function, and fitness among hypertensives.

Effect of Exercise, Escitalopram, or Placebo on Anxiety in Patients With Coronary Heart Disease: The Understanding the Benefits of Exercise and Escitalopram in Anxious Patients With Coronary Heart Disease (UNWIND) Randomized Clinical Trial

IMPORTANCE

Anxiety is common among patients with coronary heart disease (CHD) and is associated with worse health outcomes; however, effective treatment for anxiety in patients with CHD is uncertain.

OBJECTIVE

To determine whether exercise and escitalopram are better than placebo in reducing symptoms of anxiety as measured by the Hospital Anxiety and Depression-Anxiety Subscale (HADS-A) and in improving CHD risk biomarkers.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted between January 2016 and May 2020 in a tertiary care teaching hospital in the US and included 128 outpatients with stable CHD and a diagnosed anxiety disorder or a HADS-A score of 8 or higher who were older than 40 years, sedentary, and not currently receiving mental health treatment.

INTERVENTIONS

Twelve weeks of aerobic exercise 3 times per week at an intensity of 70% to 85% heart rate reserve, escitalopram (up to 20 mg per day), or placebo pill equivalent.

MAIN OUTCOMES AND MEASURES

The primary outcome was HADS-A score. CHD biomarkers included heart rate variability, baroreflex sensitivity, and flow-mediated dilation, along with 24-hour urinary catecholamines.

RESULTS

The study included 128 participants. The mean (SD) age was 64.6 (9.6) years, and 37 participants (29%) were women. Participants randomized to the exercise group and escitalopram group reported greater reductions in HADS-A (exercise, -4.0; 95% CI, -4.7 to -3.2; escitalopram, -5.7; 95% CI, -6.4 to -5.0) compared with those randomized to placebo (-3.5; 95% CI, -4.5 to -2.4; P = .03); participants randomized to escitalopram reported less anxiety compared with those randomized to exercise (-1.67; 95% CI, -2.68 to -0.66; P = .002). Significant postintervention group differences in 24-hour urinary catecholamines were found (exercise z score = 0.05; 95% CI, -0.2 to 0.3; escitalopram z score = -0.24; 95% CI, -0.4 to 0; placebo z score = 0.36; 95% CI, 0 to 0.7), with greater reductions in the exercise group and escitalopram group compared with the placebo group (F1,127 = 4.93; P = .01) and greater reductions in the escitalopram group compared with the exercise group (F1,127 = 4.37; P = .04). All groups achieved comparable but small changes in CHD biomarkers, with no differences between treatment groups.

CONCLUSIONS AND RELEVANCE

Treatment of anxiety with escitalopram was safe and effective for reducing anxiety in patients with CHD. However, the beneficial effects of exercise on anxiety symptoms were less consistent. Exercise and escitalopram did not improve CHD biomarkers of risk, which should prompt further investigation of these interventions on clinical outcomes in patients with anxiety and CHD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02516332.

Ratings of perceived exertion at the ventilatory anaerobic threshold in people with coronary heart disease: A CARE CR study

BACKGROUND

Exercise prescription guidelines for individuals undergoing cardiovascular rehabilitation (CR) are often based on heart rate training zones and rating of perceived exertion (RPE). United Kingdom guidelines indicate that patients should exercise at an intensity of RPE 11 to 14.

OBJECTIVES

We aimed to determine the accuracy of this approach by comparing this RPE range with an objectively measured marker of exercise intensity, the ventilatory anaerobic threshold (VAT), and examine whether baseline directly determined cardiorespiratory fitness (CRF) affects the association between VAT and RPE.

METHODS

Participants underwent a maximal cardiopulmonary exercise test before an 8-week community-based CR programme. Peak oxygen uptake (V̇O_2peak) and VAT were recorded, and RPE at the workload at which VAT was identified was recorded. Data were then split into tertiles, based on VO_2peak, to determine whether RPE at the VAT differed in participants with low, moderate or higher CRF.

RESULTS

We included 70 individuals [mean (SD) age 63.1 (10.0) years; body mass index 29.4 (4.0) kg/m²; 86% male]. At baseline, the mean RPE at the VAT (RPE@VAT) was 11.8 (95% confidence interval 11.0-12.6) and significantly differed between low and high CRF groups (P<0.001). The mean RPE@VAT was 10.1 (8.7-11.5), 11.8 (10.5-13.0), and 13.7 (12.5-14.9) for low, moderate and high CRF groups, respectively.

CONCLUSIONS

When using RPE to guide exercise intensity in CR populations, one must consider the effect of baseline CRF. Mean RPEs of ∼10, 12 and 14 correspond to the VAT in low, moderate and higher-fit patients, respectively.

Effects of Lifestyle Modification on Patients With Resistant Hypertension: Results of the TRIUMPH Randomized Clinical Trial

BACKGROUND

Although lifestyle modifications generally are effective in lowering blood pressure (BP) among patients with unmedicated hypertension and in those treated with 1 or 2 antihypertensive agents, the value of exercise and diet for lowering BP in patients with resistant hypertension is unknown.

METHODS

One hundred forty patients with resistant hypertension (mean age, 63 years; 48% female; 59% Black; 31% with diabetes; 21% with chronic kidney disease) were randomly assigned to a 4-month program of lifestyle modification (C-LIFE [Center-Based Lifestyle Intervention]) including dietary counseling, behavioral weight management, and exercise, or a single counseling session providing SEPA (Standardized Education and Physician Advice). The primary end point was clinic systolic BP; secondary end points included 24-hour ambulatory BP and select cardiovascular disease biomarkers including baroreflex sensitivity to quantify the influence of the baroreflex on heart rate, high-frequency heart rate variability to assess vagally mediated modulation of heart rate, flow-mediated dilation to evaluate endothelial function, pulse wave velocity to assess arterial stiffness, and left ventricular mass to characterize left ventricular structure.

RESULTS

Between-group comparisons revealed that the reduction in clinic systolic BP was greater in C-LIFE (-12.5 [95% CI, -14.9 to -10.2] mm Hg) compared with SEPA(-7.1 [-95% CI, 10.4 to -3.7] mm Hg) (P=0.005); 24-hour ambulatory systolic BP also was reduced in C-LIFE (-7.0 [95% CI, -8.5 to -4.0] mm Hg), with no change in SEPA (-0.3 [95% CI, -4.0 to 3.4] mm Hg) (P=0.001). Compared with SEPA, C-LIFE resulted in greater improvements in resting baroreflex sensitivity (2.3 ms/mm Hg [95% CI, 1.3 to 3.3] versus -1.1 ms/mm Hg [95% CI, -2.5 to 0.3]; P<0.001), high-frequency heart rate variability (0.4 ln ms² [95% CI, 0.2 to 0.6] versus -0.2 ln ms² [95% CI, -0.5 to 0.1]; P<0.001), and flow-mediated dilation (0.3% [95% CI, -0.3 to 1.0] versus -1.4% [95% CI, -2.5 to -0.3]; P=0.022). There were no between-group differences in pulse wave velocity (P=0.958) or left ventricular mass (P=0.596).

CONCLUSIONS

Diet and exercise can lower BP in patients with resistant hypertension. A 4-month structured program of diet and exercise as adjunctive therapy delivered in a cardiac rehabilitation setting results in significant reductions in clinic and ambulatory BP and improvement in selected cardiovascular disease biomarkers. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02342808.

Effects of Acute Exercise on Anxiety Ratings in Patients With Coronary Heart Disease and Elevated Anxiety

PURPOSE

To explore individual differences in state anxiety following a single, acute bout of aerobic exercise among anxious patients with diagnosed coronary heart disease (CHD).

METHODS

One hundred eighteen CHD patients with elevated symptoms of anxiety enrolled in the UNderstanding the Benefits of Exercise and Escitalopram in Anxious Patients WIth coroNary Heart Disease (UNWIND) clinical trial rated their level of anxiety using a 100-mm visual analog scale before and after a symptom-limited exercise treadmill test. A number of exercise (eg, peak oxygen uptake, exercise duration, maximum heart rate, anaerobic threshold) and psychological variables were examined as potential predictors of exercise response. Changes in anxiety and their association with psychological variables were examined using general linear models.

RESULTS

Fifty patients (42%) rated a reduction in anxiety relative to their pre-exercise ratings following the exercise treadmill test. While a number of factors were examined, the only factor that distinguished those individuals who reported a reduction in anxiety symptoms compared with those who either remained the same or actually reported an increase in anxiety was a higher pre-exercise visual analog scale anxiety rating. No differences were observed as a function of sex, severity of trait anxiety, the presence of an anxiety disorder, exercise test duration, or age.

CONCLUSIONS

Although many variables were examined, only higher baseline anxiety distinguished those who showed a reduction in their visual analog scale ratings from those whose anxiety remained the same or got worse. The extent to which the response to acute exercise predicts the anxiolytic effects of chronic exercise needs further study.

Metabolic and Neurocognitive Changes Following Lifestyle Modification: Examination of Biomarkers from the ENLIGHTEN Randomized Clinical Trial

BACKGROUND

Previous studies have demonstrated that aerobic exercise (AE) and the Dietary Approaches to Stop Hypertension (DASH) diet can improve neurocognition. However, the mechanisms by which lifestyle improves neurocognition have not been widely studied. We examined the associations between changes in metabolic, neurotrophic, and inflammatory biomarkers with executive functioning among participants from the Exercise and Nutritional Interventions for Neurocognitive Health Enhancement (ENLIGHTEN) trial.

OBJECTIVE

To examine the association between changes in metabolic function and neurocognition among older adults with cognitive impairment, but without dementia (CIND) participating in a comprehensive lifestyle intervention.

METHODS

ENLIGHTEN participants were randomized using a 2×2 factorial design to receive AE, DASH, both AE+DASH, or a health education control condition (HE) for six months. Metabolic biomarkers included insulin resistance (homeostatic model assessment [HOMA-IR]), leptin, and insulin-like growth factor (IGF-1); neurotrophic biomarkers included brain derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF); and inflammatory biomarkers included interleukin-6 (IL-6) and C-Reactive Protein (CRP).

RESULTS

Participants included 132 sedentary older adults (mean age = 65 [SD = 7]) with CIND. Results demonstrated that both AE (d = 0.48, p = 0.015) and DASH improved metabolic function (d = 0.37, p = 0.039), without comparable improvements in neurotrophic or inflammatory biomarkers. Greater improvements in metabolic function, including reduced HOMA-IR (B = -2.3 [-4.3, -0.2], p = 0.033) and increased IGF-1 (B = 3.4 [1.2, 5.7], p = 0.004), associated with increases in Executive Function.

CONCLUSION

Changes in neurocognition after lifestyle modification are associated with improved metabolic function.

Comparison of Treadmill and Cycle Ergometer Exercise During Cardiac Rehabilitation: A Meta-analysis

OBJECTIVE

To compare treadmill versus cycling-based exercise in cardiac rehabilitation (CR) on functional capacity (FC) outcomes.

DATA SOURCE

Databases were searched for randomized studies using single modality continuous exercise.

STUDY SELECTION

Studies implemented a continuous cycling or treadmill protocol for patients with either coronary artery disease (CAD) or chronic heart failure (CHF). The effect of single modality exercise on FC (VO₂peak) was analyzed. Differences in the effect of CR on FC was assessed between the mode subgroup (cycling vs treadmill) and disease state subgroup (CAD vs CHF) within both the cycling and treadmill groups.

DATA EXTRACTION

Data were extracted from 23 studies including 600 patients (mean age 60y, 86% men).

DATA SYNTHESIS

There was a significant difference in effect size between studies that used cycling, Hedges' g=0.85 (95% confidence interval [95% CI], 0.52-1.17; k=13) and studies that used treadmill exercise, Hedges' g=0.46 (95% CI, 0.22-0.70; k=8). Within cycling studies (n=14), FC was higher among CAD patients, Hedges' g=1.03 (95% CI, 0.65-1.42; k=9) compared to those with CHF, Hedges' g=0.40 (95% CI, 0.09-0.71; k=4, P<.001). Conversely, among treadmill studies (n=9), FC was higher among CHF patients, Hedges' g=0.94 (95% CI, 0.23-1.65; k=2) compared to CAD, Hedges' g=0.33 (95% CI, 0.19-0.47; k=5; P<.01).

CONCLUSIONS

According to identified studies, when cycling was the primary mode of exercise in CR, there was larger change in FC compared to treadmill exercise. In addition, CAD patients experienced greater gains in FC when cycling was the primary mode of exercise in CR, while CHF patients benefited more from treadmill-based exercise programs.

Trends in cardiorespiratory fitness: The evolution of exercise treadmill testing at a single Academic Medical Center from 1970 to 2012

OBJECTIVE

To identify temporal trends in the use of exercise treadmill testing (ETT) and cardiorespiratory fitness (CRF) estimated by ETT in metabolic equivalents (METs).

PATIENTS AND METHODS

We compiled an ETT database of all available treadmill tests-including those with concomitant stress echocardiography and nuclear perfusion imaging studies-performed at Duke University Hospital from January 1, 1970- December 31, 2012. Six different ramp protocols were used in these combined modalities. CRF at maximal exertion was estimated using established metrics. Eligible patients were required to have no missing data on maximal treadmill speed, grade, and protocol.

RESULTS

The most commonly used ETT protocol was the Bruce (n = 28,877), followed by manual test (n = 7390). Since the 1980's, the use of ETT for clinical purposes declined substantially; there was a decreased trend in utilization of 9.4% over the decades 1990-1999 and 2000-2009. When standard protocol (Bruce) was assessed in isolation, trends in CRF decreased progressively from 1970 to 2012 (mean METs (standard deviation): 11.7 (4.3) to 10.5 (3.5)). After adjusting for baseline comorbidities, the trend was reduced to a lesser degree.

CONCLUSIONS

The use of ETT at our institution has declined over time, perhaps due to changes in clinical practice. In patients undergoing ETT using the standard Bruce protocol, CRF decreased progressively over the last five decades. Future studies are needed to clarify the etiology of the decrease in use of such a powerful predictor of clinical outcomes in our medical care environment.

Lifestyle and neurocognition in older adults with cognitive impairments: A randomized trial

OBJECTIVE

To determine the independent and additive effects of aerobic exercise (AE) and the Dietary Approaches to Stop Hypertension (DASH) diet on executive functioning in adults with cognitive impairments with no dementia (CIND) and risk factors for cardiovascular disease (CVD).

METHODS

A 2-by-2 factorial (exercise/no exercise and DASH diet/no DASH diet) randomized clinical trial was conducted in 160 sedentary men and women (age >55 years) with CIND and CVD risk factors. Participants were randomly assigned to 6 months of AE, DASH diet nutritional counseling, a combination of both AE and DASH, or health education (HE). The primary endpoint was a prespecified composite measure of executive function; secondary outcomes included measures of language/verbal fluency, memory, and ratings on the modified Clinical Dementia Rating Scale.

RESULTS

Participants who engaged in AE (d = 0.32, p = 0.046) but not those who consumed the DASH diet (d = 0.30, p = 0.059) demonstrated significant improvements in the executive function domain. The largest improvements were observed for participants randomized to the combined AE and DASH diet group (d = 0.40, p = 0.012) compared to those receiving HE. Greater aerobic fitness (b = 2.3, p = 0.049), reduced CVD risk (b = 2.6, p = 0.042), and reduced sodium intake (b = 0.18, p = 0.024) were associated with improvements in executive function. There were no significant improvements in the memory or language/verbal fluency domains.

CONCLUSIONS

These preliminary findings show that AE promotes improved executive functioning in adults at risk for cognitive decline.

CLINICALTRIALSGOV IDENTIFIER

NCT01573546.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for adults with CIND, AE but not the DASH diet significantly improves executive functioning.

What is the effect of aerobic exercise intensity on cardiorespiratory fitness in those undergoing cardiac rehabilitation? A systematic review with meta-analysis

OBJECTIVE

Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science.

ELIGIBILITY CRITERIA FOR SELECTION

Studies assessing change in CRF (reported as peak oxygen uptake; V̇O_2peak) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O_2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction <40% were excluded.

RESULTS

128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O_2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absoluteV̇O_2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF.

CONCLUSION

Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O_2peak. Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O_2peak, differences in pooled effects between intensities could not be considered clinically meaningful.

REGISTRATION

Prospero CRD42016035638.

Influence of Kidney Function on Blood Pressure Response to Lifestyle Modifications: Secondary Analysis From the Exercise and Nutritional Interventions for Cardiovascular Health (ENCORE) Trial

The kidney is an important regulator of blood pressure (BP). To determine whether BP response to lifestyle modification varies across normal ranges of kidney function, the authors examined the moderating role of estimated glomerular filtration rate (eGFR) on clinic and ambulatory systolic BP (SBP) response in overweight and obese adults with unmedicated high BP. Among 144 participants of the Exercise and Nutritional Interventions for Cardiovascular Health (ENCORE) trial, mean age was 52.0±9.6 years and median eGFR was 89.1 (53-146) mL/min/1.73m2 . After multivariable regression, the interaction between eGFR and weight loss was significant for clinic (P=.023) and ambulatory SBP (P=.041). Similarly, the interaction between eGFR and improved fitness was significant for clinic (P=.041) and ambulatory SBP (P=.044). The relationship between reduced dietary sodium and SBP was not moderated by eGFR. SBP findings were inconsistent for adherence to the Dietary Approaches to Stop Hypertension (DASH) diet. These findings suggest that the effects of lifestyle modifications on SBP may be influenced by eGFR, even when kidney function is preserved.

Cardiac rehabilitation programmes: predictors of non-attendance and drop-out

BACKGROUND

Despite evidence of its benefits, attendance at cardiac rehabilitation (CR) programmes is poor. Past studies to identify predictors of non-attendance have been limited by their small sample size, particularly for female patients. The present study was designed to identify socio-demographic and clinical predictors of non-attendance and drop-out separately for men and women automatically referred to CR programmes.

METHOD AND SUBJECTS

Prospective study of CR programme attendance amongst 808 patients consecutively admitted over an 11-month period to one of two hospitals in Melbourne, Australia, after acute myocardial infarction (AMI), or to undergo coronary artery bypass graft surgery (CABGS) or percutaneous coronary intervention (PCI).

RESULTS

Of the 652 eligible patients, 573 (88%) were successfully tracked at 4 months. Of these, 284 (49.6%) had attended a CR programme, while 272 (47.5%) had not. Using logistic regression, the significant predictors of programme non-attendance among men were having had a PCI, being a non-driver, and being aged 70 or more. The only factor predictive of non-attendance for women was being aged 70 or more. Amongst attenders, 67 (23.6%) patients discontinued the programme. Being a smoker, having diabetes and being unemployed at the time of hospital admission were predictive of programme drop-out by men. Being physically inactive at admission was predictive of programme drop-out by women.

CONCLUSIONS

The present study demonstrated a relatively high rate of CR programme attendance. Special attention needs to be directed towards males who are older, PCI patients, smokers, unemployed or non-drivers, and females who are older or inactive.

New Vision for Health Promotion within Sports Medicine

Providing medical care for the treatment and prevention of injuries and health problems for competitive or recreational athletes is the most widely recognized role of sports medicine. However, the field is much broader and includes clinical practice and research in many areas related to physical activity in the prevention and treatment of chronic disease. Sports medicine and exercise science involve not only physicians and other licensed health care practitioners but also physiologists, social scientists, epidemiologists, kinesiologists, and other public health and medical professionals. There is overwhelming scientific evidence that a physically active lifestyle is important for optimal health. A key role of sports medicine is to focus the attention of a wide variety of health professionals, educators, and policy makers on developing and implementing strategies to help more individuals enjoy the many health-promoting benefits of regular physical activity.

A review of guidelines for cardiac rehabilitation exercise programmes: Is there an international consensus?

BACKGROUND

Cardiac rehabilitation is an important component in the continuum of care for individuals with cardiovascular disease, providing a multidisciplinary education and exercise programme to improve morbidity and mortality risk. Internationally, cardiac rehabilitation programmes are implemented through various models. This review compared cardiac rehabilitation guidelines in order to identify any differences and/or consensus in exercise testing, prescription and monitoring.

METHODS

Guidelines, position statements and policy documents for cardiac rehabilitation, available internationally in the English language, were identified through a search of electronic databases and government and cardiology society websites. Information about programme delivery, exercise testing, prescription and monitoring were extracted and compared.

RESULTS

Leading cardiac rehabilitation societies in North America and Europe recommend that patients progress from moderate- to vigorous-intensity aerobic endurance exercise over the course of the programme, with resistance training included as an important adjunct, for maintaining independence and quality of life. North American and European guidelines also recommend electrocardiograph-monitored exercise stress tests. Guidelines for South America and individual European nations typically include similar recommendations; however, those in the United Kingdom, Australia and New Zealand specify lower-intensity exercise and less technical assessment of functional capacity.

CONCLUSION

Higher-intensity aerobic training programmes, supplemented by resistance training, have been recommended and deemed safe for cardiac rehabilitation patients by many authorities. Based on research evidence, this may also provide superior outcomes for patients and should therefore be considered when developing an international consensus for exercise prescription in cardiac rehabilitation.

Effects of Exercise and Sertraline on Measures of Coronary Heart Disease Risk in Patients With Major Depression: Results From the SMILE-II Randomized Clinical Trial

OBJECTIVE

To assess the effects of supervised and home-based aerobic exercise training, and antidepressant pharmacotherapy (sertraline) on coronary heart disease (CHD) risk factors in a sample of participants with major depressive disorder (MDD).

METHODS

The Standard Medical Intervention versus Long-term Exercise (SMILE)-II study randomized 202 adults (153 women, 49 men) diagnosed as having MDD to one of four interventions, each of 4-month duration: supervised exercise, home-based exercise, antidepressant medication (sertraline, 50-200 mg daily), or placebo pill. Patients underwent a structured clinical interview for depression and completed the Hamilton Depression Rating Scale. CHD risk factors included brachial artery flow-mediated dilation, carotid intima-media thickness, serum lipids, and 10-year atherosclerotic cardiovascular disease (ASCVD) risk.

RESULTS

Compared with placebo, active treatment of depression (supervised exercise, home-based exercise, sertraline therapy) was associated with an improvement in CHD risk factors (improved flow-mediated dilation [p = .032], reduced progression of intima-media thickness [p = .037], and a reduction in 10-year ASCVD [p = .049]). The active treatments did not differ from each other in their effects on the CHD risk outcomes.

CONCLUSIONS

Both exercise and antidepressant medication improved CHD risk factors and lowered ASCVD risk in patients with MDD. Because MDD is associated with increased risk for CHD events, treatment of depression with exercise or sertraline may reduce the risk of developing CHD in patients with MDD.

TRIAL REGISTRATION

Clinical Trials Government Identifier: NCT-00331305.

Increased first and second pulse harmonics in Tai Chi Chuan practitioners

Background

Tai Chi Chuan (TCC) is known to be a good calisthenics for people. This study examined the relationship between pulse harmonics and autonomic nervous modulation in TCC practitioners.

Methods

Power spectral measures of right pulse wave and heart rate variability (HRV) measures were compared between TCC practitioners and control subjects. Correlation analyses between pulse harmonics and HRV measures were performed using linear regression analysis.

Results

At baseline, the total power of pulse (TPp), powers of all individual pulse harmonics, normalized power of the 1^st harmonics (nPh1) of TCC practitioners were greater, while the normalized power of the 4^th pulse harmonics (nPh4) of TCC practitioners was smaller, than those of the controls. Similarly, the baseline standard deviation (SD_RR), coefficient of variation (CV_RR), and normalized high-frequency power (nHFP) of RR intervals were smaller, while the normalized very low-frequency power (nVLFP) and low-/high- frequency power ratio (LHR) were larger in the TCC practitioners. The TCC age correlated significantly and negatively with nPh1, and nearly significantly and negatively with nPh2 in the TCC practitioners. Thirty min after TCC exercise, the percentage changes in mRRI, SD_RR, TP, VLFP were decreased, while the percentage changes in HR, ULFP, nLFP, and Ph2 were increased, relative to the controls. Correlation analysis shows that the %Ph2 correlates significantly and negatively with %mRRI and significantly and positively with %HR.

Conclusion

The TCC practitioners had increased baseline total power of pulse and the 1^st and 2^nd pulse harmonics, and decreased power of the 4^th pulse harmonics, along with decreased vagal modulation and increased sympathetic modulation. After TCC exercise, the power of the 2^nd harmonics of TCC practitioners was increased which might be related to the increase in HR due to decreased vascular resistance after TCC exercise.

Aerobic training enhances muscle deoxygenation in early post-myocardial infarction

Purpose

Exercise-induced skeletal muscle deoxygenation is startling by its absence in early post-myocardial infarction (MI) patients. Exercise training early post-MI is associated with reduced cardiovascular risk and increased aerobic capacity. We therefore investigated whether aerobic training could enhance the muscle deoxygenation in early post-MI patients.

Methods

21 ± 8 days after the first MI patients (n = 16) were divided into 12-week aerobic training (TR, n = 10) or non-training (CON, n = 6) groups. Before and after intervention, patients performed ramp bicycle exercise until exhaustion. Muscle deoxygenation was measured at vastus lateralis by near-infrared spectroscopy during exercise.

Results

Aerobic training significantly increased peak oxygen uptake (VO₂) (18.1 ± 3.0 vs. 22.9 ± 2.8 mL/kg/min), decreased the change in muscle oxygen saturation from rest to submaximal and peak exercise (∆SmO₂; 2.4 ± 5.7 vs. −7.0 ± 3.4 %), and increased the relative change in deoxygenated hemoglobin/myoglobin concentration from rest to submaximal (−1.5 ± 2.3 vs. 3.0 ± 3.6 μmol/L) and peak exercise (1.1 ± 4.5 vs. 8.2 ± 3.5 μmol/L). Change in total hemoglobin/myoglobin concentration in muscle was not significantly affected by training. In CON, no significant alterations were found after 12 weeks in either muscle deoxygenation or peak VO₂ (18.6 ± 3.8 vs. 18.9 ± 4.6 mL/kg/min). An increase in peak VO₂ was significantly negatively correlated with change in ∆SmO₂ (r = −0.65) and positively associated with change in ∆deoxy-Hb/Mb at peak exercise (r = 0.64) in TR.

Conclusions

In early post-MI patients, aerobic training enhanced skeletal muscle deoxygenation, and the enhancement was related to increased aerobic capacity.

Lifestyle modification for resistant hypertension: The TRIUMPH randomized clinical trial

BACKGROUND

Resistant hypertension (RH) is a growing health burden in this country affecting as many as 1 in 5 adults being treated for hypertension. Resistant hypertension is associated with increased risk of adverse cardiovascular disease (CVD) events and all-cause mortality. Strategies to reduce blood pressure (BP) in this high-risk population are a national priority.

METHODS

TRIUMPH is a single-site, prospective, randomized clinical trial to evaluate the efficacy of a center-based lifestyle intervention consisting of exercise training, reduced sodium and calorie Dietary Approaches to Stop Hypertension eating plan, and weight management compared to standardized education and physician advice in treating patients with RH. Patients (n = 150) will be randomized in a 2:1 ratio to receive either a 4-month supervised lifestyle intervention delivered in the setting of a cardiac rehabilitation center or to a standardized behavioral counseling session to simulate real-world medical practice. The primary end point is clinic BP; secondary end points include ambulatory BP and an array of CVD biomarkers including left ventricular hypertrophy, arterial stiffness, baroreceptor reflex sensitivity, insulin resistance, lipids, sympathetic nervous system activity, and inflammatory markers. Lifestyle habits, BP, and CVD risk factors also will be measured at 1-year follow-up.

CONCLUSIONS

The TRIUMPH randomized clinical trial (ClinicalTrials.gov NCT02342808) is designed to test the efficacy of an intensive, center-based lifestyle intervention compared to a standardized education and physician advice counseling session on BP and CVD biomarkers in patients with RH after 4 months of treatment and will determine whether lifestyle changes can be maintained for a year.

OARSI Clinical Trials Recommendations: Design and conduct of clinical trials of lifestyle diet and exercise interventions for osteoarthritis

The objective was to develop a set of "best practices" for use as a primer for those interested in entering the clinical trials field for lifestyle diet and/or exercise interventions in osteoarthritis (OA), and as a set of recommendations for experienced clinical trials investigators. A subcommittee of the non-pharmacologic therapies committee of the OARSI Clinical Trials Working Group was selected by the Steering Committee to develop a set of recommended principles for non-pharmacologic diet/exercise OA randomized clinical trials. Topics were identified for inclusion by co-authors and reviewed by the subcommittee. Resources included authors' expert opinions, traditional search methods including MEDLINE (via PubMed), and previously published guidelines. Suggested steps and considerations for study methods (e.g., recruitment and enrollment of participants, study design, intervention and assessment methods) were recommended. The recommendations set forth in this paper provide a guide from which a research group can design a lifestyle diet/exercise randomized clinical trial in patients with OA.

Supervised exercise for acute coronary patients in primary care: a randomized clinical trial

BACKGROUND

Functional capacity is a prognostic factor for coronary patients; accordingly, they are recommended to walk.

OBJECTIVE

To assess whether an exercise program supervised in primary care increases their functional capacity more than unsupervised walking.

METHODS

A randomized clinical trial was carried out at eight primary care centres of the Spanish Health Service and involving 97 incident cases of low-risk acute coronary patients, <80 years old, randomly assigned to either an unsupervised walking program (UW group; n = 51) or a 6-month cycle ergometer exercise program with gradually increasing frequency and workload intensity supervised by primary care nurses (SE group; n = 46). The two groups received the same common components of secondary prevention care. Changes in functional capacity were assessed in terms of peak oxygen consumption (VO2peak) during exercise testing measured at baseline and at 7 months by cardiologists blinded to group assignment.

RESULTS

Overall, 76% of participants completed the study, 30 in the SE and 44 in the UW. Both groups increased baseline-adjusted VO2peak: 5.56ml/kg per minute in the SE (95% confidence interval [CI] 3.38-7.74) and 1.64ml/kg per minute in the UW (95% CI -0.15 to 3.45). The multivariate-adjusted difference between groups was 4.30ml/kg per minute (95% CI 1.82-6.79; P = 0.001) when analyzing completers and 2.83ml/kg per minute (95% CI 0.61-5.05; P = 0.01) in the intention-to-treat analysis, including all participants with baseline values carried forward for those lost to follow-up.

CONCLUSIONS

A cycle ergometer exercise program supervised by primary care nurses increased the functional capacity of coronary patients more than unsupervised walking with a clinically relevant difference.

Low-intensity walking activity is associated with better health

Recommended levels of physical activity may represent challenging targets for many older adults at risk for disability, leading to the importance of evaluating whether low-intensity activity is associated with health benefits. We examined the cross-sectional association between low-intensity walking activity (<100 steps/min) and health and physical function in a group of older adults. Participants (N = 187; age = 66.8; 91.4% African American; 76.5% female) wore a StepWatch Activity Monitor to measure components of low-intensity walking activity. Only 7% of participants met physical activity guidelines and moderate-intensity activity (≥100 steps/min) contributed only 10% of the total steps/day and 2% of the total min/day. Greater amount, frequency, and duration of low-intensity activity were associated with better self-report and performance-based measures of physical function, better quality of life, and fewer depressive symptoms (ps < .05). The cross-sectional relationship between low-intensity activity and health outcomes important to independent function suggests that we further explore the longitudinal benefits of low-intensity activity.

Individualised aerobic and resistance exercise training improves cardiorespiratory fitness and reduces cardiovascular risk in patients with rheumatoid arthritis

BACKGROUND AND OBJECTIVES

Low cardiorespiratory fitness (CRF) is a significant predictor of cardiovascular disease (CVD), and interventions aiming at increasing CRF are known to reduce CVD risk. The effects of such interventions on CVD risk have not been studied in patients with rheumatoid arthritis (RA).

METHODS

40 age, gender, body mass index (BMI) and disease duration matched RA patients were allocated to either an exercise (receiving 6 months individualised aerobic and resistance high intensity exercise intervention, three times per week), or control (receiving advice on exercise benefits and lifestyle changes) arm. Participants were assessed at baseline, 3 and 6 months for aerobic capacity (VO2max), individual CVD risk factors (blood pressure, lipids, insulin resistance, body composition), 10-year CVD event probability and RA characteristics (C-reactive protein (CRP), Disease Activity Score 28 (DAS28) and Health Assessment Questionnaire (HAQ)).

RESULTS

There were no differences between groups at baseline in any of the assessed variables. VO2max (p=0.001), blood pressure (systolic: p<0.001; diastolic: p=0.003), triglycerides (p=0.030), high density lipoprotein (HDL; p=0.042), total cholesterol:HDL ratio (p=0.005), BMI (p=0.001), body fat (p=0.026), 10-year CVD event probability (p=0.012), CRP (p=0.042), DAS28 (p=0.008) and HAQ (p=0.003) were all significantly improved in the exercise versus the control group. The change in VO2max was the strongest predictor for the observed improvements in all of the assessed CVD risk factors and disease characteristics.

CONCLUSIONS

Individualised aerobic and resistance exercise intervention can lead to significantly improved CRF, individual CVD risk factors, composite CVD risk, and disease activity and severity in RA patients.

High-intensity interval training in patients with lifestyle-induced cardiometabolic disease: a systematic review and meta-analysis

BACKGROUND/AIM

Cardiorespiratory fitness (CRF) is a strong determinant of morbidity and mortality. In athletes and the general population, it is established that high-intensity interval training (HIIT) is superior to moderate-intensity continuous training (MICT) in improving CRF. This is a systematic review and meta-analysis to quantify the efficacy and safety of HIIT compared to MICT in individuals with chronic cardiometabolic lifestyle diseases.

METHODS

The included studies were required to have a population sample of chronic disease, where poor lifestyle is considered as a main contributor to the disease. The procedural quality of the studies was assessed by use of a modified Physiotherapy Evidence Base Database (PEDro) scale. A meta-analysis compared the mean difference (MD) of preintervention versus postintervention CRF (VO2peak) between HIIT and MICT.

RESULTS

10 studies with 273 patients were included in the meta-analysis. Participants had coronary artery disease, heart failure, hypertension, metabolic syndrome and obesity. There was a significantly higher increase in the VO2peak after HIIT compared to MICT (MD 3.03 mL/kg/min, 95% CI 2.00 to 4.07), equivalent to 9.1%.

CONCLUSIONS

HIIT significantly increases CRF by almost double that of MICT in patients with lifestyle-induced chronic diseases.

Effects of Short-term Exercise Training on Cardiorespiratory Fitness of Male Adults with Myocardial Infarction

[Purpose] The purpose of this study was to determine the effects of short-term exercise training on the cardiorespiratory fitness (CRF) of individuals suffering from myocardial infarction. [Subjects] A total of 60 participants were divided into experimental (EXP; n=30, mean age 56.7 ± 2.8 years, body mass 80.7 ± 10.7 kg, body height 171.9 ± 7.2 cm) and control (CON; n=30, mean age 56.5 ± 3.1 years, body mass 84.4 ± 12.4 kg, body height 171.5 ± 12.4 cm) groups. [Methods] The members of the EXP group took part in an organized daily physical exercise program (Monday through Sunday), for a period of 3 weeks. The exercise program consisted of 60 min daily specialized fitness exercises with an intensity ranging from 55-70% of the maximum heart rate, which was determined by test on a bicycle ergometer. The effects of the exercise were monitored by means of the following parameters: maximum oxygen uptake (VO2peak), resting heart rate, systolic blood pressure and diastolic blood pressure. [Results] The results indicate statistically significant post-exercise improvements in heart rate, relative oxygen uptake and systolic blood pressure, among the members of the EXP group. The results indicate that at the initial measurement of cardiorespiratory fitness no statistically significant differences were found between the groups at the multivariate level (Wilk's λ=0.83), while statistically significant differences in the cardiorespiratory fitness were found at the final measurement (Wil's λ=0.430). [Conclusion] The obtained results indicate that the exercise program, which lasted for a period of 21 days, though shorter in duration than other programs still led to statistically significant changes in the CRF of individuals suffering from MI.

Intensive weight loss intervention in older individuals: results from the Action for Health in Diabetes Type 2 diabetes mellitus trial

OBJECTIVES

To compare the effects of 4 years of intensive lifestyle intervention on weight, fitness, and cardiovascular disease risk factors in older and younger individuals.

DESIGN

Randomized controlled clinical trial.

SETTING

Sixteen U.S. clinical sites.

PARTICIPANTS

Individuals with type 2 diabetes mellitus: 1,053 aged 65 to 76 and 4,092 aged 45 to 64.

INTERVENTIONS

An intensive behavioral intervention designed to promote and maintain weight loss through caloric restriction and increased physical activity was compared with diabetes mellitus support and education.

MEASUREMENTS

Standardized assessments of weight, fitness (based on graded exercise testing), and cardiovascular disease risk factors.

RESULTS

Over 4 years, older individuals had greater intervention-related mean weight losses (6.2%) than younger participants (5.1%; interaction P = .006) and comparable relative mean increases in fitness (0.56 vs 0.53 metabolic equivalents; interaction P = .72). These benefits were seen consistently across subgroups of older adults formed according to many demographic and health factors. Of a panel of age-related health conditions, only self-reported worsening vision was associated with poorer intervention-related weight loss in older individuals. The intensive lifestyle intervention produced mean increases in high-density lipoprotein cholesterol (2.03 mg/dL; P < .001) and decreases in glycated hemoglobin (0.21%; P < .001) and waist circumference (3.52 cm; P < .001) over 4 years that were at least as large in older as in younger individuals.

CONCLUSION

Intensive lifestyle intervention targeting weight loss and increased physical activity is effective in overweight and obese older individuals to produce sustained weight loss and improvements in fitness and cardiovascular risk factors.

Determinants and consequences of adherence to the dietary approaches to stop hypertension diet in African-American and white adults with high blood pressure: results from the ENCORE trial

BACKGROUND

Although the Dietary Approaches to Stop Hypertension (DASH) diet is an accepted nonpharmacologic treatment for hypertension, little is known about what patient characteristics affect dietary adherence and what level of adherence is needed to reduce blood pressure (BP).

OBJECTIVE

Our aim was to determine what factors predict dietary adherence and the extent to which dietary adherence is necessary to produce clinically meaningful BP reductions.

DESIGN

Ancillary study of the ENCORE (Exercise and Nutrition Interventions for Cardiovascular Health) trial--a 16-week randomized clinical trial of diet and exercise.

PARTICIPANTS/SETTING

Participants included 144 sedentary, overweight, or obese adults (body mass index 25 to 39.9) with high BP (systolic 130 to 159 mm Hg and/or diastolic 85 to 99 mm Hg).

INTERVENTION

Patients were randomized to one of three groups: DASH diet alone, DASH diet plus weight management, and Usual Diet Controls.

MAIN OUTCOMES MEASURES

Our primary outcomes were a composite index of adherence to the DASH diet and clinic BP.

STATISTICAL ANALYSES PERFORMED

General linear models were used to compare treatment groups on post-treatment adherence to the DASH diet. Linear regression was used to examine potential predictors of post-treatment DASH adherence. Analysis of covariance was used to examine the relation of adherence to the DASH diet and BP.

RESULTS

Participants in the DASH diet plus weight management (16.1 systolic BP [SBP]; 95% CI 13.0 to 19.2 mm Hg and 9.9 diastolic BP [DBP]; 95% CI 8.1 to 11.6 mm Hg) and DASH diet alone (11.2 SBP; 95% CI 8.1 to 14.3 mm Hg and 7.5 DBP; 95% CI 5.8 to 9.3 mm Hg) groups showed significant reductions in BP in comparison with Usual Diet Controls participants (3.4 SBP; 95% CI 0.4 to 6.4 mm Hg and DBP 3.8; 95% CI 2.2 to 5.5 mm Hg). Greater post-treatment consumption of DASH foods was noted in both the DASH diet alone (mean = 6.20; 95% CI 5.83 to 6.57) and DASH diet plus weight management groups (mean = 6.23; 95% CI 5.88 to 6.59) compared with Usual Diet Controls (mean = 3.66; 95% CI 3.30 to 4.01; P<0.0001), and greater adherence to the DASH diet was associated with larger reductions in clinic SBP and DBP (P ≤ 0.01). Only ethnicity predicted dietary adherence, with African Americans less adherent to the DASH diet compared with whites (4.68; 95% CI 4.34 to 5.03 vs 5.83; 95% CI 5.50 to 6.11; P<0.001).

CONCLUSIONS

Greater adherence to the DASH diet was associated with larger BP reductions independent of weight loss. African Americans were less likely to be adherent to the DASH dietary eating plan compared with whites, suggesting that culturally sensitive dietary strategies might be needed to improve adherence to the DASH diet.

The influence of endothelial function and myocardial ischemia on peak oxygen consumption in patients with coronary artery disease

Impaired endothelial function has been shown to limit exercise in coronary artery disease (CAD) patients and has been implicated in myocardial ischemia. However, the association of endothelial function and ischemia on peak exercise oxygen consumption (VO₂) has not been previously reported. A total of 116 CAD patients underwent standard exercise stress testing, during which VO₂ was measured. On a separate day, endothelial-dependent and -independent function were assessed by ultrasound using flow-mediated arterial vasodilation (FMD) and sublingual glyceryl trinitrate administration (GTNMD) of the brachial artery. Patients with exercise-induced myocardial ischemia had lower FMD than nonischemic patients (3.64 ± 0.57 versus 4.98 ± 0.36, P = .050), but there was no difference in GTNMD (14.11 ± 0.99 versus 15.47 ± 0.63, P = .249). Analyses revealed that both FMD (P = .006) and GTNMD (P = .019) were related to peak VO₂. However, neither the presence of ischemia (P = .860) nor the interaction of ischemia with FMD (P = .382) and GTNMD (P = .151) was related to peak VO₂. These data suggest that poor endothelial function, potentially via impaired NO production and smooth muscle dysfunction, may be an important determinant of exercise capacity in patients with CAD, independent of myocardial ischemia.

Exercise and pharmacological treatment of depressive symptoms in patients with coronary heart disease: results from the UPBEAT (Understanding the Prognostic Benefits of Exercise and Antidepressant Therapy) study

OBJECTIVES

The aim of this study was to assess the efficacy of exercise and antidepressant medication in reducing depressive symptoms and improving cardiovascular biomarkers in depressed patients with coronary heart disease.

BACKGROUND

Although there is good evidence that clinical depression is associated with poor prognosis, optimal therapeutic strategies are currently not well defined.

METHODS

One hundred one outpatients with coronary heart disease and elevated depressive symptoms underwent assessment of depression, including a psychiatric interview and the Hamilton Rating Scale for Depression. Participants were randomized to 4 months of aerobic exercise (3 times/week), sertraline (50-200 mg/day), or placebo. Additional assessments of cardiovascular biomarkers included measures of heart rate variability, endothelial function, baroreflex sensitivity, inflammation, and platelet function.

RESULTS

After 16 weeks, all groups showed improvement on Hamilton Rating Scale for Depression scores. Participants in both the aerobic exercise (mean -7.5; 95% confidence interval: -9.8 to -5.0) and sertraline (mean -6.1; 95% confidence interval: -8.4 to -3.9) groups achieved larger reductions in depressive symptoms compared with those receiving placebo (mean -4.5; 95% confidence interval: -7.6 to -1.5; p = 0.034); exercise and sertraline were equally effective at reducing depressive symptoms (p = 0.607). Exercise and medication tended to result in greater improvements in heart rate variability compared with placebo (p = 0.052); exercise tended to result in greater improvements in heart rate variability compared with sertraline (p = 0.093).

CONCLUSIONS

Both exercise and sertraline resulted in greater reductions in depressive symptoms compared to placebo in patients with coronary heart disease. Evidence that active treatments may also improve cardiovascular biomarkers suggests that they may have a beneficial effect on clinical outcomes as well as on quality of life. (Exercise to Treat Depression in Individuals With Coronary Heart Disease; NCT00302068).

Endurance exercise intensity determination in the rehabilitation of coronary artery disease patients: a critical re-appraisal of current evidence

In the care of coronary artery disease (CAD) patients, the benefits of exercise therapy are generally established. Even though the selected endurance exercise intensity might affect medical safety, therapy adherence and effectiveness in the rehabilitation of CAD patients in how to determine endurance exercise intensity properly remains difficult. The aim of this review is to describe the available methods for endurance exercise intensity determination in the rehabilitation of CAD patients, accompanied with their (dis)advantages, validity and reproducibility. In general, endurance exercise intensity can objectively be determined in CAD patients by calculating a fraction of maximal exercise tolerance and/or determining ventilatory threshold after execution of a cardiopulmonary exercise test with ergospirometry. This can be translated to a corresponding training heart rate (HR) or workload. In the absence of ergospirometry equipment, target exercise HR can be calculated directly by different ways (fraction of maximal HR and/or Karvonen formula), and/or anaerobic threshold can be determined. However, the use of HR for determining exercise intensity during training sessions seems complicated, because many factors/conditions affect the HR. In this regard, proper standardization of the exercise sessions, as well as exercise testing, might be required to improve the accuracy of exercise intensity determination. Alternatively, subjective methods for the determination of endurance exercise intensity in CAD patients, such as the Borg ratings of perceived exertion and the talk test, have been developed. However, these methods lack proper validity and reliability to determine endurance exercise intensity in CAD patients. In conclusion, a practical and systematic approach for the determination of endurance exercise intensity in CAD patients is presented in this article.

Changes in cardiorespiratory fitness in cardiac rehabilitation patients: a meta-analysis

BACKGROUND/OBJECTIVES

Improving patients' cardiorespiratory fitness is an important therapeutic outcome in cardiac rehabilitation. The ability of cardiac rehabilitation to reduce mortality and morbidity has been evidenced through several meta-analyses. Whether cardiac rehabilitation can increase cardiorespiratory fitness and which factors may influence such gains are less well quantified.

METHODS

We performed detailed literature searches of electronic databases and manually searched papers concerning changes in cardiorespiratory fitness in cardiac rehabilitation patients. We performed random-effects meta-analysis of mean improvements in cardiorespiratory fitness and subgroup analyses to determine potential sources of heterogeneity.

RESULTS

Data from 31 studies produced 48 groups (n=3827) with a mean improvement of 1.55 (95% CI 1.21-1.89) METs, (p<0.001); equivalent to standardised effect size of ES=0.97 (95% CI 0.80-1.13). As this value was highly heterogeneous (Q=852, p<0.001) we performed subgroup analyses on the effect size data. Gains in fitness were highest in patients receiving >36 exercise sessions in studies where fitness was assessed using the Naughton Protocol. Patient characteristics associated with the highest fitness gains were age (being young) and sex (being male training in a male-only exercise group). Changes in fitness were unrelated to programme type (comprehensive or exercise-only), duration or study design. There was no association with patient's baseline fitness levels.

CONCLUSION

This is the first meta-analysis of changes in cardiovascular fitness in cardiac rehabilitation patients and shows clinically significant improvements in a large sample of patients from a variety of rehabilitation programmes. This analysis helps describe the characteristics of cardiac rehabilitation programmes which can increase patients' cardiorespiratory fitness.

The impact of training modalities on the clinical benefits of exercise intervention in patients with cardiovascular disease risk or type 2 diabetes mellitus

Exercise training intervention represents an effective means to reduce adipose tissue mass, improve glycaemic control and increase whole-body oxygen uptake capacity (VO(2peak)) in obesity, metabolic syndrome, type 2 diabetes mellitus (T2DM) and heart disease patients. In this manuscript, we review the impact of different exercise training modalities on clinical benefits of prolonged exercise intervention in these patient (sub)populations. By changing training modalities, significantly greater clinical benefits can be obtained. Greater training frequency and longer programme duration is associated with greater reduction in adipose tissue mass in obesity patients. A greater training frequency (up to 2 days/week) and a longer programme duration (up to 38 weeks) seems to be associated with greater improvements in VO(2peak) in heart disease patients. Longer programme duration and addition of resistance-type exercise further improve glycaemic control in T2DM patients. The first line of evidence seems to indicate that high-intensity interval exercise training has a greater impact on VO(2peak) in heart disease patients and insulin sensitivity in subjects with metabolic syndrome, but not on adipose tissue mass in obese subjects. However, it remains unclear whether addition of resistance-type exercise and continuous higher-intensity endurance-type exercise training are accompanied by greater improvements in VO(2peak) in heart disease patients. Furthermore, the impact of training session duration/volume on adipose tissue mass loss and glycaemic control in obesity and T2DM patients, respectively, is currently unknown. The impact of training frequency on glycaemic control remains to be investigated in T2DM patients.

Exercise fails to improve neurocognition in depressed middle-aged and older adults

PURPOSE

Although cross-sectional studies have demonstrated an association between higher levels of aerobic fitness and improved neurocognitive function, there have been relatively few interventional studies investigating this relationship, and results have been inconsistent. We assessed the effects of aerobic exercise on neurocognitive function in a randomized controlled trial of patients with major depressive disorder (MDD).

METHODS

Two-hundred and two sedentary men (n = 49) and women (n = 153), aged 40 yr and over and who met diagnostic criteria for MDD, were randomly assigned to the following: a) supervised exercise, b) home-based exercise, c) sertraline, or d) placebo pill. Before and after 4 months of treatment, participants completed measures of: Executive Function (Trail Making Test B-A difference score, Stroop Color-Word, Ruff 2 & 7 Test, Digit Symbol), Verbal Memory (Logical Memory, Verbal Paired Associates), and Verbal Fluency/Working Memory (Animal Naming, Controlled Oral Word Association Test, Digit Span). Multivariate analyses of covariance were performed to test the effects of treatment on posttreatment neuropsychological test scores, with baseline neuropsychological test scores, age, education, and change in depression scores entered as covariates.

RESULTS

The performance of exercise participants was no better than participants receiving placebo across all neuropsychological tests. Exercise participants performed better than participants receiving sertraline on tests of executive function but not on tests of verbal memory or verbal fluency/working memory.

CONCLUSIONS

We found little evidence to support the benefits of an aerobic exercise intervention on neurocognitive performance in patients with MDD.

Effects of the dietary approaches to stop hypertension diet, exercise, and caloric restriction on neurocognition in overweight adults with high blood pressure

High blood pressure increases the risks of stroke, dementia, and neurocognitive dysfunction. Although aerobic exercise and dietary modifications have been shown to reduce blood pressure, no randomized trials have examined the effects of aerobic exercise combined with dietary modification on neurocognitive functioning in individuals with high blood pressure (ie, prehypertension and stage 1 hypertension). As part of a larger investigation, 124 participants with elevated blood pressure (systolic blood pressure 130 to 159 mm Hg or diastolic blood pressure 85 to 99 mm Hg) who were sedentary and overweight or obese (body mass index: 25 to 40 kg/m(2)) were randomized to the Dietary Approaches to Stop Hypertension (DASH) diet alone, DASH combined with a behavioral weight management program including exercise and caloric restriction, or a usual diet control group. Participants completed a battery of neurocognitive tests of executive function-memory-learning and psychomotor speed at baseline and again after the 4-month intervention. Participants on the DASH diet combined with a behavioral weight management program exhibited greater improvements in executive function-memory-learning (Cohen's D=0.562; P=0.008) and psychomotor speed (Cohen's D=0.480; P=0.023), and DASH diet alone participants exhibited better psychomotor speed (Cohen's D=0.440; P=0.036) compared with the usual diet control. Neurocognitive improvements appeared to be mediated by increased aerobic fitness and weight loss. Also, participants with greater intima-medial thickness and higher systolic blood pressure showed greater improvements in executive function-memory-learning in the group on the DASH diet combined with a behavioral weight management program. In conclusion, combining aerobic exercise with the DASH diet and caloric restriction improves neurocognitive function among sedentary and overweight/obese individuals with prehypertension and hypertension.

Effects of the DASH diet alone and in combination with exercise and weight loss on blood pressure and cardiovascular biomarkers in men and women with high blood pressure: the ENCORE study

BACKGROUND

Although the DASH (Dietary Approaches to Stop Hypertension) diet has been shown to lower blood pressure (BP) in short-term feeding studies, it has not been shown to lower BP among free-living individuals, nor has it been shown to alter cardiovascular biomarkers of risk.

OBJECTIVE

To compare the DASH diet alone or combined with a weight management program with usual diet controls among participants with prehypertension or stage 1 hypertension (systolic BP, 130-159 mm Hg; or diastolic BP, 85-99 mm Hg).

DESIGN AND SETTING

Randomized, controlled trial in a tertiary care medical center with assessments at baseline and 4 months. Enrollment began October 29, 2003, and ended July 28, 2008.

PARTICIPANTS

Overweight or obese, unmedicated outpatients with high BP (N = 144).

INTERVENTIONS

Usual diet controls, DASH diet alone, and DASH diet plus weight management.

OUTCOME MEASURES

The main outcome measure is BP measured in the clinic and by ambulatory BP monitoring. Secondary outcomes included pulse wave velocity, flow-mediated dilation of the brachial artery, baroreflex sensitivity, and left ventricular mass.

RESULTS

Clinic-measured BP was reduced by 16.1/9.9 mm Hg (DASH plus weight management); 11.2/7.5 mm (DASH alone); and 3.4/3.8 mm (usual diet controls) (P < .001). A similar pattern was observed for ambulatory BP (P < .05). Greater improvement was noted for DASH plus weight management compared with DASH alone for pulse wave velocity, baroreflex sensitivity, and left ventricular mass (all P < .05).

CONCLUSION

For overweight or obese persons with above-normal BP, the addition of exercise and weight loss to the DASH diet resulted in even larger BP reductions, greater improvements in vascular and autonomic function, and reduced left ventricular mass.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00571844.

[Evidence-based guidelines for physical activity of adult Canadians]

This review of the literature provides an update on the scientific biological and psychosocial bases for Canada's Physical Activity Guide for Health Active Living, with particular reference to the effect of physical activity on the health of adults aged 20-55 years. Existing physical activity guidelines for adults from around the world are summarized briefly and compared to the Canadian guidelines. The descriptive epidemiology of physical activity and inactivity in Canada is presented, and the strength of the relationship between physical activity and specific health outcomes is evaluated, with particular emphasis on minimal and optimal physical activity requirements. Finally, areas requiring further investigation are highlighted. Summarizing the findings, Canadian and most international physical activity guidelines advocate moderate-intensity physical activity on most days of the week. Physical activity appears to reduce the risk for over 25 chronic conditions, in particular coronary heart disease, stroke, hypertension, breast cancer, colon cancer, type 2 diabetes, and osteoporosis. Current literature suggests that if the entire Canadian population followed current physical activity guidelines, approximately one-third of deaths related to coronary heart disease, one quarter of deaths related to stroke and osteoporosis, 20% of deaths related to colon cancer, hypertension, and type 2 diabetes, and 14% of deaths related to breast cancer could be prevented. It also appears that the prevention of weight gain and the maintenance of weight loss require greater physical activity levels than current recommendations.

Effects of exercise and weight loss on depressive symptoms among men and women with hypertension

OBJECTIVE

This study aimed to investigate changes in depressive symptoms in hypertensive individuals participating in an exercise and weight loss intervention.

METHODS

This study involved 133 sedentary men and women with high blood pressure (BP; 130-180 mmHg systolic BP and/or 85-110 mmHg diastolic BP) who participated in a 6-month intervention consisting of three groups: aerobic exercise, aerobic exercise and weight loss, and a waiting list control.

RESULTS

Participants in both treatment groups demonstrated significant improvements in aerobic capacity and lower BP compared with participants in the control group. Participants in the active treatment groups who had mild to moderate depressive symptoms at baseline also exhibited greater reductions in depressive symptoms compared with participants in the control group.

CONCLUSION

Results from the present study suggest that exercise, alone or combined with weight management, may reduce self-reported depressive symptoms among patients with hypertension.

Evidence-informed physical activity guidelines for Canadian adultsThis article is part of a supplement entitled Advancing physical activity measurement and guidelines in Canada: a scientific review and evidence-based foundation for the future of Canadian physical activity guidelines co-published by Applied Physiology, Nutrition, and Metabolism and the Canadian Journal of Public Health. It may be cited as Appl. Physiol. Nutr. Metab. 32(Suppl. 2E) or as Can. J. Public Health 98(Suppl. 2)

This review of the literature provides an update on the scientific biological and psychosocial bases for Canada’s physical activity guide for healthy active living, with particular reference to the effect of physical activity on the health of adults aged 20–55 years. Existing physical activity guidelines for adults from around the world are summarized briefly and compared with the Canadian guidelines. The descriptive epidemiology of physical activity and inactivity in Canada is presented, and the strength of the relationship between physical activity and specific health outcomes is evaluated, with particular emphasis on minimal and optimal physical activity requirements. Finally, areas requiring further investigation are highlighted. Summarizing the findings, Canadian and most international physical activity guidelines advocate moderate-intensity physical activity on most days of the week. Physical activity appears to reduce the risk for over 25 chronic conditions, in particular coronary heart disease, stroke, hypertension, breast cancer, colon cancer, type 2 diabetes, and osteoporosis. Current literature suggests that if the entire Canadian population followed current physical activity guidelines, approximately one third of deaths related to coronary heart disease, one quarter of deaths related to stroke and osteoporosis, 20% of deaths related to colon cancer, hypertension, and type 2 diabetes, and 14% of deaths related to breast cancer could be prevented. It also appears that the prevention of weight gain and the maintenance of weight loss require greater physical activity levels than current recommendations.

Exercise and pharmacotherapy in the treatment of major depressive disorder

OBJECTIVE

To assess whether patients receiving aerobic exercise training performed either at home or in a supervised group setting achieve reductions in depression comparable to standard antidepressant medication (sertraline) and greater reductions in depression compared to placebo controls.

METHODS

Between October 2000 and November 2005, we performed a prospective, randomized controlled trial (SMILE study) with allocation concealment and blinded outcome assessment in a tertiary care teaching hospital. A total of 202 adults (153 women; 49 men) diagnosed with major depression were assigned randomly to one of four conditions: supervised exercise in a group setting; home-based exercise; antidepressant medication (sertraline, 50-200 mg daily); or placebo pill for 16 weeks. Patients underwent the structured clinical interview for depression and completed the Hamilton Depression Rating Scale (HAM-D).

RESULTS

After 4 months of treatment, 41% of the participants achieved remission, defined as no longer meeting the criteria for major depressive disorder (MDD) and a HAM-D score of <8. Patients receiving active treatments tended to have higher remission rates than the placebo controls: supervised exercise = 45%; home-based exercise = 40%; medication = 47%; placebo = 31% (p = .057). All treatment groups had lower HAM-D scores after treatment; scores for the active treatment groups were not significantly different from the placebo group (p = .23).

CONCLUSIONS

The efficacy of exercise in patients seems generally comparable with patients receiving antidepressant medication and both tend to be better than the placebo in patients with MDD. Placebo response rates were high, suggesting that a considerable portion of the therapeutic response is determined by patient expectations, ongoing symptom monitoring, attention, and other nonspecific factors.

Changes of serum beta-endorphin by programmed exercise training are correlated with improvement of clinical symptoms and quality of life in female mitral valve prolapse syndrome

BACKGROUND

Mitral valve prolapse (MVP) is a common entity in female population. Although this is a minor disease, it may cause annoying symptoms that impair quality of life (QOL), and no established therapy for this problem. The aim of this study isto examine whether programmed exercise training by treadmill in female MVP syndrome would improve clinical symptoms and QOL.

METHODS

An interventional study of 39 females with MVP syndrome with treadmill exercise endurance training for 12 weeks. Every individual received training for 30 min a day, thrice a week for 12 weeks. Baseline and post-exercise at 12 weeks serum beta-endorphins were measured. Symptom improvement was assessed by the MVP symptom checklist questionnaire and the Euro-QOL-5D was used to measure QOL improvement in these females.

RESULTS

The mean serum beta-endorphin increased from 0.5 to 1.68 ng/ml (p = 0.001) in the exercise group (n = 18) after 12 weeks exercise, whereas the control group (n = 21) did not show any significant changes (0.44 vs. 0.43 ng/ml). Major symptoms of MVP such as chest pain, palpitation, fatigue were improved significantly by the assessment of MVP symptom checklist. The QOL of the exercised females also showed significant changes.

CONCLUSIONS

Through programmed exercise training in these MVP females, the improvement of symptoms and QOL is parallel to the increase of serum beta-endorphin. This result implicates that MVP females should initiate exercise to tackle this annoying problem.

Health benefits of physical activity: the evidence

The primary purpose of this narrative review was to evaluate the current literature and to provide further insight into the role physical inactivity plays in the development of chronic disease and premature death. We confirm that there is irrefutable evidence of the effectiveness of regular physical activity in the primary and secondary prevention of several chronic diseases (e.g., cardiovascular disease, diabetes, cancer, hypertension, obesity, depression and osteoporosis) and premature death. We also reveal that the current Health Canada physical activity guidelines are sufficient to elicit health benefits, especially in previously sedentary people. There appears to be a linear relation between physical activity and health status, such that a further increase in physical activity and fitness will lead to additional improvements in health status.

Cost-effectiveness of rehabilitation after an acute coronary event: a randomised controlled trial

OBJECTIVE

To estimate the incremental effects on cost and quality of life of cardiac rehabilitation after an acute coronary syndrome.

DESIGN

Open randomised controlled trial with 1 year's follow-up. Analysis was on an intention-to-treat basis.

SETTING

Two tertiary hospitals in Sydney.

INTERVENTION

18 sessions of comprehensive exercise-based outpatient cardiac rehabilitation or conventional care as provided by the treating doctor.

PARTICIPANTS

113 patients aged 41-75 years who were self-caring and literate in English. Patients with uncompensated heart failure, uncontrolled arrhythmias, severe and symptomatic aortic stenosis or physical impairment were excluded.

MAIN OUTCOME MEASURES

Costs (hospitalisations, medication use, outpatient visits, investigations, and personal expenses); and measures of quality of life. Incremental cost per quality-adjusted life year (QALY) saved at 1 year (this estimate combines within-study utility effects with reported 1-year risk of survival and treatment effects of rehabilitation on mortality). Sensitivity analyses around a base case estimate included alternative assumptions of no treatment effect on survival, 3 years of treatment effect on survival and variations in utility.

RESULTS

The estimated incremental cost per QALY saved for rehabilitation relative to standard care was 42,535 US dollars when modelling included the reported treatment effect on survival. This increased to 70,580 US dollars per QALY saved if treatment effect on survival was not included. The results were sensitive to variations in utility and ranged from 19,685 US dollars per QALY saved to rehabilitation not being cost-effective.

CONCLUSIONS

The effects on quality of life tend to reinforce treatment advantages on survival for patients having postdischarge rehabilitation after an acute coronary syndrome. The estimated base case incremental cost per QALY saved is consistent with those historically accepted by decision making authorities such as the Pharmaceutical Benefits Advisory Committee.

Home versus center based physical activity programs in older adults

BACKGROUND

Physical inactivity is a leading cause of preventable death and morbidity in developed countries. In addition physical activity can potentially be an effective treatment for various medical conditions (e.g. cardiovascular disease, osteoarthritis). Many types of physical activity programs exist ranging from simple home exercise programs to intense highly supervised hospital (center) based programs.

OBJECTIVES

To assess the effectiveness of 'home based' versus 'center based' physical activity programs on the health of older adults.

SEARCH STRATEGY

The reviewers searched the Cochrane Central Register of Controlled Trials (CENTRAL) (1991-present), MEDLINE (1966-Sept 2002), EMBASE (1988 to Sept 2002), CINAHL (1982-Sept 2002), Health Star (1975-Sept 2002), Dissertation Abstracts (1980 to Sept 2002), Sport Discus (1975-Sept 2002) and Science Citation Index (1975-Sept 2002), reference lists of relevant articles and contacted principal authors where possible.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of different physical activity interventions in older adults (50 years or older) comparing a 'home based' to a 'center based' exercise program. Study participants had to have either a recognised cardiovascular risk factor, or existing cardiovascular disease, or chronic obstructive airways disease (COPD) or osteoarthritis. Cardiac and post-operative programs within one year of the event were excluded.

DATA COLLECTION AND ANALYSIS

Three reviewers selected and appraised the identified studies independently. Data from studies that then met the inclusion/exclusion criteria were extracted by two additional reviewers.

MAIN RESULTS

Six trials including 224 participants who received a 'home based' exercise program and 148 who received a 'center based' exercise program were included in this review. Five studies were of medium quality and one poor. A meta-analysis was not undertaken given the heterogeneity of these studies. CARDIOVASCULAR. The largest trial (accounting for approximately 60% of the participants) looked at sedentary older adults. Three trials looked at patients with peripheral vascular disease (intermittent claudication). In patients with peripheral vascular disease center based programs were superior to home at improving distance walked and time to claudication pain at up to 6 months. However the risk of a training effect may be high. There are no longer term studies in this population. Notably home based programs appeared to have a significantly higher adherence rate than center based programs. However this was based primarily on the one study (with the highest quality rating of the studies found) of sedentary older adults. This showed an adherence rate of 68% in the home based program at two year follow-up compared with a 36% adherence in the center based group. There was essentially no difference in terms of treadmill performance or cardiovascular risk factors between groups. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). Two trials looked at older adults with COPD. In patients with COPD the evidence is conflicting. One study showed similar changes in various physiological measures at 3 months that persisted in the home based group up to 18 months but not in the center based group. The other study showed significantly better improvements in physiological measures in the center based group after 8 weeks but again the possibility of a training effect is high. OSTEOARTHRITIS. No studies were found. None of the studies dealt with measures of cost, or health service utilization.

AUTHORS' CONCLUSIONS

In the short-term, center based programs are superior to home based programs in patients with PVD. There is a high possibility of a training effect however as the center based groups were trained primarily on treadmills (and the home based were not) and the outcome measures were treadmill based. There is conflicting evidence which is better in patients with COPD. Home based programs appear to be superior to center based programs in terms of the adherence to exercise (especially in the long-term).

High intensity aerobic interval exercise is superior to moderate intensity exercise for increasing aerobic capacity in patients with coronary artery disease

BACKGROUND

Increased aerobic exercise capacity appears to reduce both all-cause mortality and cardiovascular disease mortality. Physical exercise to improve peak oxygen uptake (VO2peak) is thus strongly recommended, however evidence regarding the most efficient training intensity for patients with coronary artery disease (CAD) is still lacking. The purpose of this randomized study was therefore to assess the effects of high intensity aerobic interval exercise compared to moderate intensity exercise, representing the same total training load, for increasing VO2peak in stable CAD-patients.

METHODS

Twenty-one stable CAD-patients were randomized to supervised treadmill walking at either high intensity (80-90% of VO2peak) or moderate intensity (50-60% of VO2peak) three times a week for 10 weeks.

RESULTS

After training VO2peak increased by 17.9% (P=0.012) in the high intensity group and 7.9% (P=0.038) in the moderate intensity group. The training-induced adaptation was significantly higher in the high intensity group (P=0.011).

CONCLUSIONS

High intensity aerobic interval exercise is superior to moderate exercise for increasing VO2peak in stable CAD-patients. As VO2peak seems to reflect a continuum between health and cardiovascular disease and death, the present data may be useful in designing effective training programmes for improved health in the future.

Effects of increased training load on vagal-related indexes of heart rate variability: a novel sleep approach

There is little doubt that moderate training improves cardiac vagal activity and thus has a cardioprotective effect against lethal arrhythmias. Our purpose was to learn whether a higher training load would further increase this beneficial effect. Cardiac autonomic control was inferred from heart rate variability (HRV) and analyzed in three groups of young subjects (24.5 ± 3.0 yr) with different training states in a period free of stressful stimuli or overload. HRV was analyzed in 5-min segments during slow-wave sleep (SWS, a parasympathetic state that offers high electrocardiographic stationarity) and compared with data collected during quiet waking periods in the morning. Sleep parameters, fatigue, and stress levels checked by questionnaire were identical for all three groups with no signs of overtraining in the highly trained (HT) participants. During SWS, a significant ( P < 0.05) increase in absolute and normalized vagal-related HRV indexes was observed in moderately trained (MT) individuals compared with sedentary (Sed) subjects; this increase did not persist in HT athletes. During waking periods, most of the absolute HRV indexes indistinctly increased in MT individuals compared with controls ( P < 0.05) but did not increase in HT athletes. Normalized spectral HRV indexes did not change significantly among the three groups. Heart rate was similar for MT and Sed subjects but was significantly ( P < 0.05) lower in HT athletes under both recording conditions. These results indicate that SWS discriminates the state of sympathovagal balance better than waking periods. A moderate training load is sufficient to increase vagal-related HRV indexes. However, in HT individuals, despite lower heart rate, vagal-related HRV indexes return to Sed values even in the absence of competition, fatigue, or overload.

Exercise prescription using resting heart rate plus 20 or perceived exertion in cardiac rehabilitation

PURPOSE

For patients starting a cardiac rehabilitation program, exercise intensity often is set 20 beats per minute above the standing resting heart rate (RHR+20) or in a range of 11 to 13 on Borg's Scale for Rating of Perceived Exertion (RPE 11-13). The purpose of this study was to determine the actual exercise intensity, expressed as a percentage of peak oxygen uptake reserve (%VO2R) using these techniques.

METHODS

For this study, 11 new referrals to a phase 2 cardiac rehabilitation program voluntarily underwent a symptom-limited exercise test and a field test that consisted of self-paced over-the-ground walking for 10 minutes at levels corresponding to RPE 11-13 and RHR+20. During both tests, gas exchange data were obtained via the Cosmed K4b and heart rate via the Polar monitor.

RESULTS

The mean %VO2R at RHR+20 (41.8 +/- 12.3%) and RPE 11-13 (71 +/- 15.3% mL.kg.min) were significantly different. Exercise at RHR+20 resulted in 4 of the 11 patients (36%) exercising at less than 40% VO2R, 6 of the patients (55%) exercising at 40% to 60% VO2R, and 1 of the patients (9%) exercising at more than 60% VO2R. Exercise at RPE 11-13 resulted in 1 of the 11 patients (9%) exercising at less than 40% VO2R, 1 of the patients at exercising at 40% to 60% VO2R (9%), and 9 of the patients (82%) exercising at more than 60% VO2R.

CONCLUSIONS

The results of this study indicate that using RHR+20 or RPE 11-13 to prescribe exercise intensity during over-the-ground walking for phase 2 cardiac rehabilitation patients results in substantial intersubject variability and raises questions about the safety and efficacy of these approaches.