Exercise Tolerance In Individuals Research Articles

Effect of respiratory rehabilitation on quality of life in individuals with post-COVID-19 symptoms: A randomised controlled trial.

Inspiratory and expiratory muscle training (RMT) has been shown to have beneficial effects in individuals with long-term post-COVID-19 symptoms. To assess the effects of adding RMT to an aerobic exercise (AE) training program for health-related quality of life (HRQoL) and exercise tolerance in individuals with long-term post-COVID-19 symptoms, and to evaluate the effects on physical and lung function, and psychological status. 64 individuals with long-term post-COVID-19 symptoms of fatigue and dyspnoea were randomly assigned to AE+RMT or AE+RMTsham groups for an 8-wk intervention (AE: 50min/day, 2 times/wk; RMT: 40min/day, 3 times/wk). Primary outcomes were HRQoL (EuroQol-5D questionnaire) and exercise tolerance (cardiopulmonary exercise test). Secondary outcomes were physical function: respiratory muscle function (inspiratory/expiratory muscle strength and inspiratory muscle endurance), lower and upper limb strength (1-min Sit-to-Stand and handgrip force); lung function: spirometry testing and lung diffusing capacity; and psychological status (anxiety/depressive levels). Postintervention, there were no statistically significant improvements in HRQoL or exercise tolerance in the AE+RMT compared with the AE+RMTsham group. In the AE+RMT group, large improvements in respiratory muscle function (d = 0.7 to 1.3) and low-moderate improvements in peak expiratory flow (d = 0.4) occurred compared with the AE+RMTsham group. Lung function outcomes, lower and upper limb strength and psychological status did not increase more in the AE+RMT group than in the AE+RMTsham group. For individuals with long-term post-COVID-19 symptoms, combining RMT with an AE training program resulted in improvements in respiratory muscle strength, inspiratory muscle endurance and peak expiratory flow; however, the differences between groups were not statistically significant for HRQoL, exercise tolerance, psychological distress, and lung diffusing capacity. United States Clinical Trials Registry (NCT05597774).

Head and neck cooling enhance exercise tolerance in individuals with multiple sclerosis

BackgroundIndividuals with Multiple Sclerosis (MS) experience impairments in heat dissipation, compromising core temperature regulation during exercise. ObjectiveTo examine the efficacy of combined head-and-neck cooling as administered via a commercially available cooling cap and neck wrap in mitigating increases in core temperature during exercise. MethodsOn separate days, ten (7 females) adults (46.1 ± 11.6 years) with relapsing-remitting MS performed semi-recumbent cycling consisting of an incremental exercise bout to volitional fatigue in a temperate environment (23 °C, 50 % relative humidity) while undergoing head-and-neck cooling using a cooling cap and neck wrap maintained at 10 °C (COLD) or 24–26 °C (NEUTRAL). Prior to and following a 30-minute post-exercise recovery, functional capacity was assessed by a battery of tests consisting of a 2-minute walk test, Timed 25-Foot Walk test, sit-to-stand test, and Berg Balance Scale. Core (ingestible pill) and skin temperatures were recorded continuously. The level of fatigue was measured with questionnaires. ResultsThe duration of the incremental exercise test increased with the application of COLD (28.4 ± 5.1 min) versus NEUTRAL water (vs 20.8 ± 5.1 min) (p = 0.001) and was paralleled by a significant reduction in body temperatures (∼1 °C, p < 0.05). The distance covered during the 2-min walk test performed after the incremental exercise test increased with the COLD (176.5 ± 0.6 m), relative to the NEUTRAL condition (147.7 ± 43.5 m) (p = 0.01). Fatigue levels did not change between conditions. ConclusionWe show that head-and-neck cooling with cold water effectively enhances exercise tolerance and mitigates increases in core temperature during exercise in individuals with MS.

Feasibility of superimposed supine cycling and lower body negative pressure as an effective means of prolonging exercise tolerance in individuals experiencing persisting post-concussive symptoms: Preliminary results.

To examine the feasibility, utility and safety of superimposed lower body negative pressure (LBNP) and tilt during supine cycling in individuals suffering from persisting post-concussive symptoms (PPCS). Elevenindividuals aged 17-31 (6 females/5 males) participated in two randomized separate visits, 1week apart. A ramp-incremental test was performed during both visits until volitional failure. Visits included no pressure (control) or LBNP at -40Torr (experimental) with head-up tilt at 15degrees (females) or 30degrees (males). Transcranial Doppler ultrasound was utilized to quantify middle cerebral artery velocity (MCAv), while symptom reports were filled out before and 0, 10, and 60min post-exertion. Ratings of exertion and overall condition followed similar trends for participants across both tests. The relative increase in MCAv was blunted during the experimental condition (8%) compared to control (24%), while a greater heart rate (17 beats/min) was achieved during the LBNP condition (P=0.047). Symptom severity at the 0 and 10minpost-exertion time points displayed negligible-to-small effect sizes between conditions (Wilcoxon's r<0.11). Symptom reporting was lower at the 60min post-exertion time point with these displaying a moderate effect size (Wilcoxon's r=0.31). The combination of LBNP and tilt during supine cycling did not change the participants' subjective interpretation of the exertional test but attenuated the hyperpnia-induced vasodilatory MCAv response, while also enabling participants to achieve a higher heart rate during exercise and reduced symptoms 1h later. As this protocol is safe and feasible, further research is warranted in this area for developing PPCS treatment options. HIGHLIGHTS: What is the central question of this study? What are the feasibility, safety and utility of combining head-up tilt with lower body negative pressure during supine cycling for blunting the increase in cerebral blood velocity seen during moderate-intensity exercise in individuals experiencing persisting post-concussion symptoms? What is the main finding and its importance? Although no differences were found in symptoms between conditions within the first 10min following exertion, symptom severity scores showed a clinically meaningful reduction 60min following the experimental condition compared to the non-experimental control condition.

HIIT as a Safe and Effective Exercise Modality for Improving Pulmonary Function and Exercise Tolerance in Individuals with Asthma

Background – Asthma is a chronic inflammatory disorder affecting millionsglobally, with symptoms including wheezing, chest tightness, and shortnessof breath. Regular physical activity can mitigate these symptoms; however,the effectiveness and safety of HIIT for asthmatics remain underexplored.This study addresses this gap by examining HIIT's impact on asthmaticindividuals, focusing on pulmonary function, FeNO levels (an inflammationmarker), and exercise tolerance.Materials and MethodsFourteen adult males, divided into asthmatic (n=7) and healthy control (n=7)groups, underwent a two-week HIIT protocol. Pulmonary function wasassessed using peak expiratory flow (PEF), forced vital capacity (FVC), andforced expiratory volume in one second (FEV1/FVC ratio). FeNO wasmeasured with a portable device, and exercise tolerance was evaluatedthrough a progressive exercise test on a cycle ergometer to determine peakoxygen uptake (VO2peak), carbon dioxide output (VCO2peak), ventilation(VE), and time to exhaustion (TTE). Statistical analysis was performed usingANOVA with repeated measures.ResultsThe results indicated significant differences between groups in FeNO, VO2peak, TTE, and peak work rate (WR), with no significant changes inpulmonary function measures. Asthmatics showed a marked improvement inTTE and peak WR post-HIIT, with mean FeNO levels and pulmonaryfunction measures remaining unchanged from baseline. Specifically, postHIIT, asthmatics achieved higher VE, VCO2, TTE, and peak WR,demonstrating improved exercise tolerance and ventilation withoutexacerbating lung inflammation.ConclusionHIIT was well-tolerated by individuals with asthma, leading to significantimprovements in exercise tolerance and ventilation without negativelyimpacting pulmonary function or increasing lung inflammation. Thesefindings suggest HIIT as a safe and effective exercise modality for asthmatics,potentially aiding in better asthma management through enhanced physicalfitness and exercise capacity.

Symptoms Associated With Exercise Intolerance and Resting Heart Rate Following Mild Traumatic Brain Injury.

People may experience a myriad of symptoms after mild traumatic brain injury (mTBI), but the relationship between symptoms and objective assessments is poorly characterized. This study sought to investigate the association between symptoms, resting heart rate (HR), and exercise tolerance in individuals following mTBI, with a secondary aim to examine the relationship between symptom-based clinical profiles and recovery. Prospective observational study of adults aged 18 to 65 years who had sustained mTBI within the previous 7 days. Symptoms were assessed using the Post-Concussion Symptom Scale, HR was measured at rest, and exercise tolerance was assessed using the Buffalo Concussion Bike Test. Symptom burden and symptom-based clinical profiles were examined with respect to exercise tolerance and resting HR. Data from 32 participants were assessed (mean age 36.5 ± 12.6 years, 41% female, 5.7 ± 1.1 days since injury). Symptom burden (number of symptoms and symptom severity) was significantly associated with exercise intolerance ( P = .002 and P = .025, respectively). Physiological and vestibular-ocular clinical profile composite groups were associated with exercise tolerance ( P = .001 and P = .014, respectively), with individuals who were exercise intolerant having a higher mean number of symptoms in each profile than those who were exercise tolerant. Mood-related and autonomic clinical profiles were associated with a higher resting HR (>80 bpm) ( P = .048 and P = .028, respectively), suggesting altered autonomic response for participants with symptoms relating to this profile. After adjusting for age and mechanism of injury (sports- or non-sports-related), having a higher mood-related clinical profile was associated with persisting symptoms at 3 months postinjury (adjusted odds ratio = 2.08; 95% CI, 1.11-3.90; P = .013). Symptom-based clinical profiles, in conjunction with objective measures such as resting HR and exercise tolerance, are important components of clinical care for those having sustained mTBI. These results provide preliminary support for the concept that specific symptoms are indicative of autonomic dysfunction following mTBI.

Repeated oral sucrose dosing after the second wind is unnecessary in patients with McArdle disease: Results from a randomized, placebo-controlled, double-blind, cross-over study.

It is well-established that oral sucrose ingested shortly before exercise improves early exercise tolerance in individuals with McArdle disease. This is by supplying blood-borne glucose for muscle metabolism to compensate for the blocked glycogenolysis. The present study investigated if individuals with McArdle disease could benefit further from repeated sucrose ingestion during prolonged exercise. In this double-blind, placebo-controlled, cross-over study, the participants were randomized to ingest either sucrose or placebo first and subsequently the opposite on two separate days. The participants ingested the drink 10 min before and thrice (after 10, 25, and 40 min) during a 60-min submaximal exercise test on a cycle ergometer. The primary outcome was exercise capacity as indicated by heart rate (HR) and perceived exertion (PE) responses to exercise. Secondary outcomes included changes in blood metabolites, insulin and carbohydrate, and fatty acid oxidation rates during exercise. Nine participants with McArdle disease were included in the study. We confirmed improvement of exercise capacity with oral sucrose vs. placebo during early exercise (pre-second wind) indicated by lower peak HR and PE (p < 0.02). We found no further beneficial effect with repeated sucrose versus placebo ingestion during prolonged exercise, as indicated by no difference in HR or PE post-second wind (p > 0.05). Glucose, lactate, insulin, and carbohydrate oxidation rates increased, and fatty acid oxidation decreased with sucrose versus placebo (p ≤ 0.0002). We can conclude that repeated sucrose ingestion is not recommended during prolonged exercise. This finding can prevent excessive caloric intake and reduce the risk of obesity and insulin resistance.

Exercise Pathophysiology and Testing in Individuals With a Fontan Circulation.

The Fontan circulation, a surgical palliation for single-ventricle congenital heart disease, profoundly impacts the cardiopulmonary response to exercise. Reliant on passive pulmonary blood flow, the Fontan circulation has limited capacity to augment cardiac output as necessary to supply working muscles during exercise. Cardiopulmonary exercise testing (CPET) objectively assesses cardiorespiratory fitness and provides insight into the etiology of exercise intolerance. Furthermore, CPET variables, such as peak oxygen consumption and submaximal variables, have prognostic value and may be used as meaningful endpoints in research studies. CPET is also useful in clinical research applications to assess the effect of pharmacologic or other interventions. Medical therapies to improve exercise tolerance in individuals with a Fontan circulation, such as pulmonary vasodilators, may modestly improve peak oxygen consumption. Exercise training focused on aerobic fitness and lower extremity strength may have a more consistent and larger impact on these measures of aerobic fitness. CPET is a valuable diagnostic and prognostic tool for those with a Fontan circulation. Newer ancillary assessments, such as noninvasive peripheral venous pressure monitoring and cardiac output measurements, hold promise to provide a more nuanced insight into the underlying pathophysiology.

Lower-limb resistance training reduces exertional dyspnea and intrinsic neuromuscular fatigability in individuals with chronic obstructive pulmonary disease.

Skeletal muscle atrophy, dysfunction, and fatigue are important complications of chronic obstructive pulmonary disease (COPD). Greater reliance on glycolytic metabolism and increased type III/IV muscle afferent activity increase ventilatory drive, promote ventilatory constraint, amplify exertional dyspnea, and limit exercise tolerance. To investigate whether muscular adaptation with resistance training (RT) could improve exertional dyspnea, exercise tolerance, and intrinsic neuromuscular fatigability in individuals with COPD (n = 14, FEV1 = 62 ± 21% predicted), we performed a proof-of-concept single-arm efficacy study utilizing 4 wk of individualized lower-limb RT (3 times/wk). At baseline, dyspnea (Borg scale), ventilatory parameters, lung volumes (inspiratory capacity maneuvers), and exercise time were measured during a constant-load test (CLT) at 75% maximal workload to symptom limitation. On a separate day, fatigability was assessed using 3 min of intermittent stimulation of the quadriceps (initial output of ∼25% maximal voluntary force). Following RT, the CLT and fatigue protocols were repeated. Compared with baseline, isotime dyspnea was reduced (5.9 ± 2.4 vs. 4.5 ± 2.4 Borg units, P = 0.02) and exercise time increased (437 ± 405 s vs. 606 ± 447 s, P < 0.01) following RT. Isotime tidal volume increased (P = 0.01), whereas end-expiratory lung volumes (P = 0.02) and heart rate (P = 0.03) decreased. Quadriceps force, relative to initial force, was higher at the end of the stimulation protocol posttraining (53.2 ± 9.1 vs. 46.8 ± 11.9%, P = 0.04). This study provides evidence that 4 wk of RT attenuates exertional dyspnea and improves exercise tolerance in individuals with COPD, which in part, is likely due to delayed ventilatory constraint and reduced intrinsic fatigability. A pulmonary rehabilitation program beginning with individualized lower-limb RT may help mitigate dyspnea before performing aerobic training in individuals with COPD.NEW & NOTEWORTHY This study presents the novel finding that 4-wk resistance training (RT) focused specifically on the lower limbs can reduce exertional dyspnea during constant-load cycling, improve exercise tolerance, and reduce intrinsic fatigability of the quadriceps in individuals with COPD.

Home-based respiratory muscle training on quality of life and exercise tolerance in long-term post-COVID-19: Randomized controlled trial.

To evaluate the effects of a home-based respiratory muscle training programme (inspiratory [IMT] or inspiratory/expiratory muscles [RMT]) supervised by telerehabilitation on quality of life and exercise tolerance in individuals with long-term post-COVID-19 symptoms. The secondary objective was to evaluate the effects of these programmes on respiratory muscle function, physical and lung function, and psychological state. 88 individuals with long-term symptoms of fatigue and dyspnoea after COVID-19 diagnosis were randomly (1:1 ratio) assigned to IMT, IMTsham, RMT or RMTsham groups for an 8-week intervention (40min/day, 6 times/week). Primary outcomes were quality of life (EuroQol-5D questionnaire) and exercise tolerance (Ruffier test). Secondary outcomes were respiratory muscle function (inspiratory/expiratory muscle strength; inspiratory muscle endurance), physical function (lower and upper limb strength [1-min Sit-to-Stand and handgrip force]), lung function (forced spirometry), and psychological status (anxiety/depression levels and post-traumatic stress disorder). All outcomes were measured pre-, intermediate- (4th week), and post-intervention. At post-intervention, there was a statistically significant and large (d>0.90) improvement in quality of life, but not in exercise tolerance, in the RMT group compared with the RMTsham group. Both of the real training groups produced a statistically significant and large increase in inspiratory muscle strength and endurance (d≥0.80) and in lower limb muscle strength (d≥0.77) compared with the 2 sham groups. Expiratory muscle strength and peak expiratory flow showed a statistically significant and large (d≥0.87) increase in the RMT group compared with the other 3 groups. Only an 8-week supervised home-based RMT programme was effective in improving quality of life, but not exercise tolerance, in individuals with long-term post-COVID-19 symptoms. In addition, IMT and RMT programmes were effective in improving respiratory muscle function and lower limb muscle strength, but had no impact on lung function and psychological status.

The mediating role of inhibitory control in the relationship between prefrontal cortex hemodynamics and exercise performance in adults with overweight or obesity

Physical inactivity has been suggested to impair physical performance, cognitive functions and facilitate weight gain. One hypothesis is that long periods of physical inactivity could impair oxygen delivery to the prefrontal cortex (PFC), impairing one's cognitive ability to inhibit unhealthy automated behaviors and, therefore, reduce exercise tolerance. The present study sought to further understand the relationship among PFC hemodynamics, inhibitory control, and exercise tolerance in individuals with low physical fitness levels who are overweight or obese. Thirty-four participants were asked to perform a series of inhibitory control tests (i.e., Stroop task) in one testing session and complete an incremental cycling exercise test with hemodynamic fluctuations of the PFC measured with functional near-infrared spectroscopy in another session. Our results indicate that exercise performance varied with PFC oxygenation. We also found that inhibitory control played a key role mediating the relationship between PFC oxygenation and exercise performance, suggesting that the cognitive ability to inhibit automated responses has an impact on exercise behavior in adults with overweight and obesity.

Management of Progressive Fibrosing Interstitial Lung Diseases (PF-ILD).

Progressive fibrosing interstitial lung diseases (PF-ILD) consist of a diverse group of interstitial lung diseases (ILD) characterized by a similar clinical phenotype of accelerated respiratory failure, frequent disease exacerbation and earlier mortality. Regardless of underlying disease process, PF-ILD progresses through similar mechanisms of self-sustained dysregulated cell repair, fibroblast proliferation and alveolar dysfunction that can be therapeutically targeted. Antifibrotic therapy with nintedanib or pirfenidone slow lung function decline and are the backbone of treatment for IPF with an expanded indication of PF-ILD for nintedanib. Immunosuppression is utilized for some subtypes of PF-ILD, including connective tissue disease ILD and hypersensitivity pneumonitis. Inhaled treprostinil is a novel therapy that improves exercise tolerance in individuals with PF-ILD and concomitant World Health Organization (WHO) group 3 pulmonary hypertension. Lung transplantation is the only curative therapy and can be considered in an appropriate and interested patient. Supportive care, oxygen therapy when appropriate, and treatment of comorbid conditions are important aspects of PF-ILD management. This review summarizes the current data and recommendations for management of PF-ILD.

Construct validity and reproducibility of the six-minute step test in subjects with obstructive sleep apnea treated with continuous positive airway pressure.

ABSTRACTObjective:To evaluate the construct validity and reproducibility of the six-minute step test (6MST) in individuals with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP). Methods:We evaluated 48 volunteers diagnosed with OSA and treated with CPAP for at least two months. The volunteers underwent the six-minute walk test (6MWT) and the 6MST, in random order and on different days, with an interval of, at most, seven days between the two tests. Results:A moderate positive correlation was found between the distance walked on the 6MWT and the number of steps climbed on the 6MST (r = 0.520; p < 0.001). There was no significant difference between the two 6MSTs in terms of the number of steps climbed (121.7 ± 27.1 vs. 123.6 ± 26.7). Reproducibility for performance on the 6MST and for cardiovascular variables was considered excellent (intraclass correlation coefficient > 0.8). Regarding cardiovascular responses, the 6MST produced higher values than did the 6MWT for HR at six minutes, percent predicted maximum HR, and leg fatigue at six minutes, as well as for systolic blood pressure at six minutes and at one minute of recovery. Conclusions:The 6MST is valid and reproducible, producing greater cardiovascular stress than does the 6MWT. However, the 6MST is also characterized as a submaximal test for the assessment of exercise tolerance in individuals with OSA treated with CPAP.

Medical technology in rehabilitational counseling from the “Electronic Healthcare” perspective

Aim.To evaluate the readiness of acute coronary syndrome patients to distant physical rehabilitation (DPR) during the office rehabilitational counseling (ORC).Material and methods.Open retrospective study included data of 148 patients (117 males, 31 female), who had participated in ORC with the aim to include to DPR. Main part of ORC was conducted in the format of physician work with a computerized algorithm. Completeness of data to form the programs of physical rehabilitation (PR) was assessed manually with reviewing of the discharge summaries. Clinical status was assessed, and if necessary, the 6 minute walking test was conducted. Motivational component was assessed by the results of questionnaire “Program of calculation of motivational readiness of patients to adhere clinician recommendations”. Cognition was assessed with MMSE.Results.The part of “electronic” discharge summaries was 88,5%. Analysis of availability of epicrise data for algorithm modules showed that only 134 patients (97,3%) had complete data in clinical diagnosis. Also, an insufficiency was shown for number of stress tests with ECG registration: 22 (14,9%), but 96 (64,9%) with 6-minute test. In 30 patients (20,2%) the data on exercise tests was lacking. Data on PR regimen and related assessment of individual exercise tolerance was found in 34 (23% of ORC); and all who passed in-hospital stage. To the program of DPR about 1/3 (31,1%) of ORC participants were included. Under the framework of ORC, PR programs were created for all patients. By the results of investigation, a generalized clinical and instrumental characteristics of DPR patients were formulated, with added motivational and psychological specificities.Conclusion.It is found that in every 5th myocardial infarction patient discharged from hospital, there is lack of data on individual PR parameters that significantly reduces the ability of primary care physician in prescription and implementation of PR events. Usage of eHealth instruments at outpatient stage of cardiorehabilitation make it to solve these issues of ORC, which has as its tasks the PR programs formulation and evaluation of patient readiness for ORC participation.

Bioelectric Impedance Analysis of Visceral Fat in Women with Polycystic Ovarian Syndrome and the Effect of Exercise: A Pilot Study

ABSTRACTAimsTo determine the body fat distribution in 30 women with polycystic ovarian syndrome (PCOS) using bioelectric impedance analysis (BIA) and assess the effect of a 2-month structured exercise on body fat, menstrual function and fertility outcomes.Materials and methodsThirty women with PCOS underwent assessment of body composition with BIA. Their body mass index (BMI), total body fat (TBF), visceral fat (VF) and subcutaneous fat were analyzed. Two-month structured exercises were advised based on individual exercise tolerance. The postexercise parameters were reassessed. Outcome measures studied were improvement in BMI, TBF, VF, subcutaneous fat, menstrual functions, and fertility outcomes.ResultsA significant reduction in BMI, VF and subcutaneous fat was found in these women after exercise. Results were further analyzed after dividing them into three groups based on their BMI (normal, overweight, and obese). There was a significant reduction in all parameters (BMI, TBF, visceral and subcutaneous fat) in the overweight group. In the obese group, there was a significant drop in BMI and VF and to a lesser extent in the TBF. In women with normal BMI, a significant drop was noted in TBF only. On follow-up, five women reported regularization of their menstrual cycles and four others managed to conceiveConclusionTotal body fat and VF can be cost-effectively measured by a simple tool called BIA. Tailor-made exercises based on individual tolerance are effective in improving these parameters even when done over a short duration. These improvements do positively impact the menstrual dysfunctions and subfertility.Clinical significanceThese findings will help in better management of women with PCOS and ensure optimal improvement in menstrual dysfunction and fertility outcomesHow to cite this articlePallavi G, Pai P, Kumar P, Maiya AG, Ramachandra P. Bioelectric Impedance Analysis of Visceral Fat in Women with Polycystic Ovarian Syndrome and the Effect of Exercise: A Pilot Study. Int J Infertil Fetal Med 2016;7(3):89-93.

Effects of Pedometer Use in Veterans With Chronic Heart Failure

Routine physical activity can improve exercise tolerance in individuals with chronic heart failure (HF). Lack of exercise can lead to worsening of HF. This study examined the effect of a pedometer on exercise tolerance in veterans with chronic HF. Although both pedometer and routine exercise groups improved 6-minute walk test distance, the use of a pedometer was not better than routine exercise in improvement in exercise tolerance after 6 weeks. Factors that may have impacted the effectiveness of pedometer use include pedometer malfunction, low pedometer compliance, and severe wintery weather.

Effects of a Prolonged Exercise Program on Exercise Tolerance in Individuals with History of Acute Coronary Syndrome: A Retrospective Study

Objective : To verify the influence of a prolonged physical exercise program on physical fitness and cardiovascular parameters, as evaluated by exercise stress test (EST), in subjects with newly diagnosed acute coronary syndrome. Methods : The sample included 50 subjects distributed by an experimental group (EG; n = 25) and a control group (CG; n = 25). The EG was subject to a program of regular exercise during 52 weeks. All subjects performed two ESTs: one at the beginning and one at the end of the experimental protocol. The first test was performed 2-3 months after the cardiac event. During the EST fitness parameters (speed and incline of the treadmill and test time), cardiovascular parameters (maximum and resting heart rate, maximum and resting blood pressure, and maximum and resting double product), and metabolic equivalents were recorded. Results : Compared with the first test, in the second EST showed a significant increase (p <0.05) of the absolute values of metabolic equivalents and physical fitness indicators (testing time and maximum speed and incline of the treadmill) in the EG, with a percentage of variation of these parameters significantly higher than in CG. Despite the better physical performance demonstrated by the EG, there were no significant differences between the two groups with respect to cardiovascular parameters. Conclusion : In this study, the physical training program improved exercise tolerance in individuals with a history of acute coronary events, without an apparent increased cardiac work.

The Effects of Dietary Nitrate (Beetroot Juice) Supplementation on Exercise Performance: A Review

Nitric oxide (NO) is a potent vasodilator that increases blood flow and induces various intracellular actions such as increased mitochondrial and contractile efficiency. NO bioavailability may be increased by direct consumption of dietary nitrate and its sequential reduction to nitrite, a regulator of NO-induced hypoxic signaling. Dietary nitrate consumption reduces blood pressure, protects from ischemia-reperfusion injury, and improves endothelial dysfunction. Recently, the popularity of dietary nitrate as an ergogenic aid has been increased dramatically. Most exercise studies have administered dietary nitrate in the form of beetroot juice containing 5-8 mmol of nitrate and a few studies have used sodium and potassium nitrate (8-10 mg/kg). The most prominent and consistent effects of dietary nitrate supplementation is a reduction in the oxygen cost of exercise and an increase in exhaustion time at submaximal workloads. This effect was observed after either a single bolus (2-3 h prior to exercise) or a long-term (2-15 days) supplementation. The ergogenic effects of beetroot supplementation appear to be dose-dependent and are most often observed after long-term ingestion (approximately 6 days), at high exercise intensities and in less fit individuals. The ergogenic value of beetroot supplementation in endurance athletes is not clear; many studies have documented no improvements and a few studies an enhanced performance (0.4% to 3%) in time- and distance-trials. Clearly, more research is needed to document (i) the optimal dosage of beetroot ingestion for enhancing exercise performance in athletes, (ii) the effects of dietary nitrate consumption on training adaptations, (iii) the efficacy of beetroot supplementation in increasing exercise tolerance in individuals with chronic disease, and (iv) the safety of long-term beetroot consumption.

Cardiorespiratory function associated with dietary nitrate supplementation

The advent of medical nutrition therapy and nutritional physiology affords the opportunity to link diet to specific cardiovascular mechanisms, suggesting novel treatments for cardiovascular disease. This study tests the hypothesis that beetroot juice increases the plasma nitric oxide (NO) concentration, which is associated with improvements in cardiorespiratory function at rest and during submaximal aerobic exercise. The subjects were 12 healthy, young adult, normotensive African-American females, with a body mass of 61 ± 2 kg, body fat of 28% ± 4%, and peak oxygen consumption of 26 ± 3 mL·kg(-1)·min(-1). The subjects were studied at rest and during cycle ergometer exercise at 40%, 60%, and 80% of peak oxygen consumption. Plasma NO concentration, respiratory quotient (RQ), minute ventilation, systolic and diastolic blood pressure (SBP and DBP), heart rate, and oxygen consumption were compared between isocaloric, isovolumetric placebo control orange juice and experimental beetroot juice treatments on separate days. The beetroot juice treatment increased plasma NO concentration and decreased oxygen consumption, SBP, and the heart rate-SBP product at rest and at 40%, 60%, and 80% of peak oxygen consumption in the absence of significant effects on RQ, minute ventilation, heart rate, and DBP. These findings suggest that, in healthy subjects, beetroot juice treatments increase plasma NO concentration and decrease cardiac afterload and myocardial oxygen demand at rest and during 3 submaximal levels of aerobic exercise. Future studies should determine the cellular and molecular mechanisms responsible for the improvement in cardiorespiratory function associated with dietary nitrate supplementation and whether they translate into better cardiovascular function and exercise tolerance in individuals with a compromised cardiovascular system.

Optimal duration of pulmonary rehabilitation for individuals with chronic obstructive pulmonary disease - a systematic review

The purpose of this review was to determine the impact of duration of pulmonary rehabilitation on measures of health-related quality of life and exercise tolerance in individuals with chronic obstructive pulmonary disease (COPD). Randomized controlled trials (RCTs) comparing different lengths of pulmonary rehabilitation in patients with COPD were identified after searches of six electronic databases (MEDLINE, PubMed, CINAHL, EMBASE, Physiotherapy Evidence Database [PEDro] and the Cochrane Library of clinical trials) and reference lists of pertinent articles. Two reviewers performed the searches and assessed trial quality using PEDro and Jadad scales. Five RCTs met inclusion criteria. The mean PEDro score was 6 (range 3-8) and mean Jadad was 2 (range 1-3). Three trials reported a difference in health-related quality of life in favour of the longer duration program; two trials reported a benefit in exercise capacity in favour of longer programs. A meta-analysis of results was not possible due to considerable heterogeneity in program duration and outcomes. Longer duration pulmonary rehabilitation programs appear to have a more favourable effect on health-related quality of life in individuals with COPD; results for exercise capacity are less clear. The limited literature prevents a more definitive conclusion on optimal duration of rehabilitation.

Exercise with angina and cramp?

Exercise with angina and cramp?