Feasibility of telerehabilitation for heart failure patients inaccessible for outpatient rehabilitation.

AIMS: Despite strong recommendations, outpatient cardiac rehabilitation is underused in chronic heart failure (CHF) patients. Possible barriers are frailty, accessibility, and rural living, which may be overcome by telerehabilitation. We designed a randomized, controlled trial to evaluate the feasibility of a 3-month real-time, home-based telerehabilitation, high-intensity exercise programme for CHF patients who are either unable or unwilling to participate in standard outpatient cardiac rehabilitation and to explore outcomes of self-efficacy and physical fitness at 3 months post-intervention. METHODS AND RESULTS: CHF patients with reduced (≤40%), mildly reduced (41-49%), or preserved ejection fraction (≥50%) (n = 61) were randomized 1:1 to telerehabilitation or control in a prospective controlled trial. The telerehabilitation group (n = 31) received real-time, home-based, high-intensity exercise for 3 months. Inclusion criteria were (i) ≥18 years, (ii) New York Heart Association class II-III, stable on optimized medical therapy for >4 weeks, and (iii) N-terminal pro-brain natriuretic peptide >300 ng/L. All participants participated in a 2-day 'Living with heart failure' course. No other intervention beyond standard care was provided for controls. Outcome measures were adherence, adverse events, self-reported outcome measures, the general perceived self-efficacy scale, peak oxygen uptake (VO2peak ) and a 6-min walk test (6MWT). The mean age was 67.6 (11.3) years, and 18% were women. Most of the telerehabilitation group (80%) was adherent or partly adherent. No adverse events were reported during supervised exercise. Ninety-six per cent (26/27) reported that they felt safe during real-time, home-based telerehabilitation, high-intensity exercise, and 96% (24/25) reported that, after the home-based supervised telerehabilitation, they were motivated to participate in further exercise training. More than half the population (15/26) reported minor technical issues with the videoconferencing software. 6MWT distance increased significantly in the telerehabilitation group (19 m, P = 0.02), whereas a significant decrease in VO2peak (-0.72 mL/kg/min, P = 0.03) was observed in the control group. There were no significant differences between the groups in general perceived self-efficacy scale, VO2peak , and 6MWT distance after intervention or at 3 months post-intervention. CONCLUSIONS: Home-based telerehabilitation was feasible in chronic heart failure patients inaccessible for outpatient cardiac rehabilitation. Most participants were adherent when given more time and felt safe exercising at home under supervision, and no adverse events occurred. The trial suggests that telerehabilitation can increase the use of cardiac rehabilitation, but the clinical benefit of telerehabilitation must be evaluated in larger trials.

Indexing cardiac volumes for peak oxygen uptake to improve differentiation of physiological and pathological remodeling: from elite athletes to heart failure patients.

AIMS: Cardiovascular structures adapt to meet metabolic demands, but current methodology for indexing by body size does not accurately reflect such variations. Therefore, we aimed to investigate how left ventricular end-diastolic volume (LVEDV) and left atrial maximal volume (LAVmax) are associated with absolute (L/min) peak oxygen uptake (VO2peak) and fat-free mass (FFM) compared to body surface area (BSA). We subsequently assessed the impact of indexing by absolute VO2peak, FFM, and BSA to discriminate pathological from physiological remodeling. METHODS AND RESULTS: We used data from 1190 healthy adults to explore relationships for BSA, FFM, and absolute VO2peak with LVEDV and LAVmax by regression and correlation analyses. We then compared these indexing methods for classification to normalcy/pathology in 61 heart failure patients and 71 endurance athletes using the chi-squared and Fisher exact tests and the net reclassification and integrated discrimination indices. Absolute VO2peak correlated strongly with LVEDV, explaining 52% of variance vs. 32% for BSA and 44% for FFM. Indexing LVEDV for VO2peak improved discrimination between heart failure patients and athletes on top of indexing to BSA. Seventeen out of 18 athletes classified to pathology by BSA were reclassified to normalcy by VO2peak indexing (P < 0.001), while heart failure patients were reclassified to pathology (39-95%, P < 0.001). All indexing methods explained below 20% of the variance in LAVmax in univariate models. CONCLUSIONS: Indexing LVEDV to VO2peak improves the ability to differentiate physiological and pathological enlargement. The LVEDV to absolute VO2peak ratio may be a key index in diagnosing heart failure and evaluating the athlete's heart.

Cardiorenal syndrome and the association with fitness: Data from a telerehabilitation randomized clinical trial.

AIMS: To investigate the associations of cardiorespiratory fitness with cardiac, vascular, renal and cardiorenal characteristics in chronic heart failure in a telerehabilitation randomized clinical trial. Secondly, to evaluate the associations of cardiorenal syndrome with the effects of exercise. METHODS AND RESULTS: Sixty-nine heart failure patients attended baseline examination, and 61 patients were randomly assigned 1:1 to 3-month telerehabilitation or control. Data were collected at baseline and 3-month post-intervention, including echocardiography and vascular ultrasound, laboratory tests, exercise test with peak oxygen consumption (VO2peak ) measurement and 6-min walk test (6MWT). Baseline VO2peak and 6MWT distance was 0.85 mL*min-1 *kg-1 lower and 20 m shorter per 10 mL/min/1.73m2 lower estimated glomerular filtration rate (both P < 0.001). Heart failure patients with cardiorenal syndrome had 3.5 (1.1) mL*min-1 *kg-1 lower VO2peak and diastolic dysfunction grade 2-3, and elevated filling pressure was >50% more common compared with those without (all P < 0.05). At the 3-month post-intervention follow-up, only the non-CRS patients in the intervention group increased VO2peak (0.73 (0.51) mL*min-1 *kg-1 ), whereas VO2peak in the CRS subpopulation of controls decreased (-1.34 (0.43) mL*min-1 *kg-1 ). Cardiorenal syndrome was associated with a decrease in VO2peak in CRS patients compared with non-CRS patients, -0.91 (0.31) vs. 0.39 (0.35) mL*min-1 *kg-1 respectively, P = 0.013. CONCLUSIONS: Cardiorenal syndrome was negatively associated with VO2peak and 6MWT distance in chronic HF, and the associations were stronger than for heart failure phenotypes and other characteristics. The effect of exercise was negatively associated with cardiorenal syndrome. Exercise seems to be as important in heart failure patients with cardiorenal syndrome, and future studies should include CRS patients to reveal the most beneficial type of exercise.

Blood Volume, Hemoglobin Mass, and Peak Oxygen Uptake in Older Adults: The Generation 100 Study.

Purpose: To investigate the association between blood volume, hemoglobin mass (Hbmass), and peak oxygen uptake (VO2peak) in healthy older adults. Methods: Fifty fit or unfit participants from the prospective randomized Generation 100 Study (n = 1,566) were included (age- and sex-specific VO2peak above or below average values). Blood, plasma, and erythrocyte volume and Hbmass were tested using the carbon monoxide rebreathing method within 1 week after VO2peak testing. Results: Mean age, BMI, Hbmass, blood volume, and VO2peak were 73.0 ± 2.1 years, 24.8 ± 3.3 kg·m2, 10.0 ± 1.7 g·kg-1, 76.4 ± 11.8 mL·kg-1, and 33.5 ± 8.4 mL·kg-1·min-1. VO2peak in fit and unfit participants and women and men were 38.6 ± 6.5 and 25.8 ± 3.8 mL·kg-1·min-1, 30.7 ± 7.6 mL·kg-1·min-1, and 35.5 ± 8.5 mL·kg-1·min-1, respectively. Women were shorter (Δ14 cm), leaner (Δ13 kg), and with less muscle mass (Δ9%) than men (P < 0.05). Relative erythrocyte volume and Hbmass were lower in women, and blood and erythrocyte volume and Hbmass were higher in the fit participants (P < 0.05). Hbmass and erythrocyte volume explained 40 and 37%, respectively, of the variability in VO2peak, with a limited effect of physical-activity adjustment (40 and 38%, respectively). Blood and plasma volume explained 15 and 25%, respectively, of VO2peak variability, and the association was strengthened adjusting for physical activity (25 and 31%, respectively), indicating a training-dependent adaptation in plasma but not erythrocyte volume (p ≤ 0.006). Conclusions: Blood and plasma volumes were moderately associated with VO2peak in healthy older men and women, and the association was strengthened after adjustment for physical activity. Hbmass and erythrocyte volume were strongly associated with VO2peak but unrelated to physical activity.

The relationship between maximum heart rate in a cardiorespiratory fitness test and in a maximum heart rate test.

OBJECTIVES: It is suggested that individuals will not reach their heart rate maximum (HRmax) at an incremental cardiorespiratory fitness (CRF) test and commonly five beats per minute (bpm) are added to the highest heart rate (HR) reached. To our knowledge, there is not sufficient data justifying such estimation. Our aim was to assess whether individuals reached HRmax in an incremental CRF test to exhaustion. DESIGN AND METHODS: Fifty-one males and 57 females (aged 22-70 years) completed both an incremental CRF test (gradual increase in speed and/or inclination until volitional exhaustion) and a test designed to reach HRmax (with repeated work bouts at high intensity before maximal exertion) ≥48h apart. We investigated the relationship between the highest HR in the two tests using hierarchical linear regression analysis, with HRmax from the HRmax test as a dependent variable, and the highest HR reached at the CRF test (HRcrf), whether maximum oxygen uptake was reached on the CRF test, CRF, sex and age as independent variables. RESULTS: HRmax was 2.2 (95% confidence interval, 1.5-2.9) bpm higher in the test designed to reach HRmax than in the CRF test (p<0.001). Only HRcrf significantly predicted HRmax, with no contribution of the other variables in the model. HRmax was predicted from the highest HR reached in an incremental CRF test by multiplying HRcrf with 0.967, and adding 8.197 (HRmax=8.197+[0.967×HRcrf]) beats/min. CONCLUSION: Non-athletes reached close to HRmax in a standard CRF test.

Women undergoing assisted fertilisation and high-intensity interval training: a pilot randomised controlled trial.

OBJECTIVES: Overweight and obese women often seek assisted fertilisation. In the obese population, pregnancy rates are 30%-75% below that of normal weight women who undergo assisted fertilisation. We hypothesised that high-intensity interval training (HIT) would improve fertility by improving insulin sensitivity and thus affect the hypothalamic-pituitary-ovarian axis and ovarian androgen production. Our aim was to assess whether HIT prior to assisted fertilisation would increase pregnancy rate. METHODS: Eighteen overweight and obese women (body mass index>25.0 kg/m2) were randomised to HIT (n=8) or usual care (control, n=10) before assisted fertilisation. HIT was undertaken three times weekly for 10 weeks; two sessions of 4×4 min HIT and one session of 10×1 min HIT. Primary outcome was ongoing pregnancy. Secondary outcomes included insulin sensitivity, reproductive hormones, oxygen uptake and body composition. RESULTS: Four women got pregnant in both the HIT group (50%) and in the control group (44%), no between-group difference (p=0.6). Insulin sensitivity (glucose infusion rate) improved significantly after HIT, from 264.1 mg/m2/min (95% CI 193.9 to 334.4) at baseline to 324.7 mg/m2/min (95% CI 247.2 to 402.2) after 10 weeks (between-group difference, p=0.04). Fasting glucose, visceral fat, waist circumference and VO2peak were significantly improved in the group that undertook HIT. CONCLUSIONS: HIT significantly improved insulin sensitivity, VO2peak and abdominal fat. Low statistical power makes it difficult to conclude on whether HIT prior to assisted fertilisation could increase pregnancy rate. Larger trials are needed to determine if improvements in insulin sensitivity are clinically relevant for assisted fertilisation success rates in this population.

Exercise prior to assisted fertilization in overweight and obese women (FertilEX): study protocol for a randomized controlled trial.

BACKGROUND: Overweight and obese women show reduced conception rates compared to women of normal weight. Insulin resistance and increased amount of visceral fat may be important mechanisms for reduced fertility in these women. Exercise training, in particular with high intensity, has previously been found to improve insulin sensitivity in overweight subjects. This study will assess if regular high-intensity interval training will improve the pregnancy rate after assisted fertilization compared to usual care only in overweight and obese women. We hypothesize that the intervention will improve pregnancy rate and insulin sensitivity compared to the control group. METHODS/DESIGN: The FertilEX study is a randomized, controlled trial in which 140 women with body mass index (BMI) >25 kg/m(2) accepted for assisted fertilization will be randomized (1:1) to an intervention group or a control group. The intervention group will do high-intensity interval training three times per week for 10 weeks before assisted fertilization. The control group will receive standard care assisted fertilization only. The primary outcome measure is ongoing pregnancy 7-8 weeks after embryo transfer. Secondary outcome measures are insulin sensitivity, peak oxygen uptake, brachial flow-mediated endothelial function, levels of reproductive hormones, and body composition. DISCUSSION: The results of this trial will provide knowledge about the effects of high-intensity exercise before assisted fertilization in subfertile overweight/obese women. If the intervention leads to beneficial effects on outcome measures, such programs should be considered as part of regular fertility care procedures for this population of women. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01933633 . Registered on 28 August 2013.

Effects of High Intensity Interval Training and Strength Training on Metabolic, Cardiovascular and Hormonal Outcomes in Women with Polycystic Ovary Syndrome: A Pilot Study.

BACKGROUND: Polycystic ovary syndrome is a common endocrinopathy in reproductive-age women, and associates with insulin resistance. Exercise is advocated in this disorder, but little knowledge exists on the optimal exercise regimes. We assessed the effects of high intensity interval training and strength training on metabolic, cardiovascular, and hormonal outcomes in women with polycystic ovary syndrome. MATERIALS AND METHODS: Three-arm parallel randomized controlled trial. Thirty-one women with polycystic ovary syndrome (age 27.2 ± 5.5 years; body mass index 26.7 ± 6.0 kg/m2) were randomly assigned to high intensity interval training, strength training, or a control group. The exercise groups exercised three times weekly for 10 weeks. RESULTS: The main outcome measure was change in homeostatic assessment of insulin resistance (HOMA-IR). HOMA-IR improved significantly only after high intensity interval training, by -0.83 (95% confidence interval [CI], -1.45, -0.20), equal to 17%, with between-group difference (p = 0.014). After high intensity interval training, high-density lipoprotein cholesterol increased by 0.2 (95% CI, 0.02, 0.5) mmol/L, with between group difference (p = 0.04). Endothelial function, measured as flow-mediated dilatation of the brachial artery, increased significantly after high intensity interval training, by 2.0 (95% CI, 0.1, 4.0) %, between-group difference (p = 0.08). Fat percentage decreased significantly after both exercise regimes, without changes in body weight. After strength training, anti-Müllarian hormone was significantly reduced, by -14.8 (95% CI, -21.2, -8.4) pmol/L, between-group difference (p = 0.04). There were no significant changes in high-sensitivity C-reactive protein, adiponectin or leptin in any group. CONCLUSIONS: High intensity interval training for ten weeks improved insulin resistance, without weight loss, in women with polycystic ovary syndrome. Body composition improved significantly after both strength training and high intensity interval training. This pilot study indicates that exercise training can improve the cardiometabolic profile in polycystic ovary syndrome in the absence of weight loss. TRIAL REGISTRATION: ClinicalTrial.gov NCT01919281.

How to Be 80 Year Old and Have a VO2max of a 35 Year Old.

UNLABELLED: Background. To discuss the cardiovascular and pulmonary physiology and common risk factors of an 80-year-old man with a world record maximal oxygen uptake of 50 mL·kg(-1)·min(-1). Methods. CASE REPORT: Results. His maximal oxygen uptake of 3.31 L·min(-1), maximal heart rate of 175 beats·min(-1), and maximal oxygen pulse of 19 mL·beats(-1) are high. He is lean (66.6 kg) and muscular (49% skeletal muscle mass). His echo parameters of mitral flow (left ventricular filling, E = 82 cm·s(-1) and E/A = 1.2) were normal for 40- to 60-year-old men. Systolic and diastolic function increased adequately during exercise, with no increase in left ventricular filling pressure. He has excellent pulmonary function (FVC = 4.31 L, FEV1 = 3.41, FEV1/FVC = 0.79, and DLCO = 12.0 Si(1)) and normal FMD and blood volumes (5.8 L). He has a high level of daily activity (10,900 steps·day(-1) and 2:51 hours·day(-1) of physical activity) and a lifelong history of physical activity. Conclusion. The man is in excellent cardiopulmonary fitness and is highly physically active. His cardiac and pulmonary functions are above expectations for his age, and his VO2max is comparable to that of an inactive 25-year-old and of a normal, active 35-year-old Norwegian man.

Sport-Specific Physiological Adaptations in Highly Trained Endurance Athletes.

PURPOSE: This study aims to compare maximal oxygen uptake (V˙O2max), blood volume (BV), hemoglobin mass (Hbmass), and brachial endothelial function, measured as flow-mediated dilatation (FMD), in international-level endurance athletes primarily exercising with the whole body (cross-country skiing), lower body (orienteering), or upper body (flatwater kayak). METHODS: Seventeen cross-country skiers, 15 orienteers, and 11 flatwater kayakers were tested for V˙O2max, BV, Hbmass, and FMD. Additionally, body composition and annual training (type, volume, and intensity of training) were analyzed. RESULTS: Absolute and body-mass-normalized V˙O2max values were 11.3% and 9.9% higher, respectively, in skiers (5.83 ± 0.60 L·min and 77.9 ± 4.2 mL·min·kg) compared to orienteers (5.24 ± 0.45 L·min and 70.9 ± 3.5 mL·min·kg) (P < 0.01), whereas kayakers (5.78 ± 0.56 L·min and 73.7 ± 6.3 mL·min·kg) did not differ from skiers. BV was 9.9%-11.8% higher in skiers and orienteers compared to kayakers when normalized for total body mass and fat-free mass, and skiers had 9.2% and 9.9% higher Hbmass normalized for total body mass and fat-free mass compared to kayakers (all P < 0.05). Arterial diameter was 11.8%-15.0% larger in kayakers (4.38 ± 0.63 mm) and skiers (4.22 ± 0.36 mm) compared to orienteers (3.81 ± 0.32 mm) (P < 0.05), whereas FMD did not differ between groups. CONCLUSIONS: This study indicates that higher V˙O2max in cross-country skiers and greater arterial diameters in the arms of skiers and kayakers are sport-specific physiological adaptations to chronic endurance training in whole-body and upper-body exercise modes. However, variations in these variables are not associated with BV or Hbmass.

Community-based participatory research in a large cohort study of chronic diseases among Alaska native adults.

BACKGROUND: In 2001, the National Cancer Institute (NCI) funded a project to develop methods to recruit American Indian and Alaska Native (AI/AN) adults for a prospective cohort study of chronic disease risk and protective factors. OBJECTIVE: We describe how the use of community-based participatory research (CBPR) principles led to more effective study design and implementation in a study in Alaska. METHODS: CBPR elements included collaboration between researchers and tribes at all stages of the project, capacity building through training AI/AN staff in research methods, and knowledge dissemination through presentations, newsletters, and individual and community health feedback based on results of the study. RESULTS: Between March 2004 and August 2006, 3,821 AI/ AN adults from 26 Alaskan communities enrolled in the study. Retention in the study is high, with over 88% of participants successfully completing a 2-year follow-up questionnaire. CONCLUSION: CBPR methods have facilitated effective development of study methods, recruitment and retention. Efforts are on-going to continue work with this unique AI/AN research participant community.