Acute whole-body electromyostimulation associated with dynamic exercises did not alter cardiac autonomic modulation and oxygen uptake in obese and eutrophic men

Abstract Aim: To contrast the acute effects of whole-body electromyostimulation (WB-EMS) with sham associated with dynamic exercises on cardiovascular, ventilatory, metabolic, and autonomic responses in men with obesity and controls. Methods: A randomized cross-over and double-blind trial with nine eutrophic (23.6 years; 23 ± 1.4 kg/m2) and ten men with obesity (26 ± 4 years; 38 ± 7 kg/m2), who were randomized to receive WB-EMS-Sham or Sham-WB-EMS with 30 min of rest between protocols. WB-EMS protocol (Miha Bodytec®) was applied at the motor level, frequency = 85 Hz, pulse duration = 350 μs, cycle on = 6′; cycle off = 4′. Sham group performed the same exercises with the electric current turned off. Throughout both protocols, subjects executed two dynamic exercises of 5 minutes each (step-up and step down associated with shoulder flexion, and lunge exercise associated with elbow flexion) in the same order. R-R intervals and breath-by-breath respiratory gases analysis were collected during the protocols. Heart rate variability (HRV) indexes were obtained using linear and nonlinear analysis. The level of statistical significance was set at p < 0.05. Results: Regarding both exercises, participants with obesity presented reduced oxygen uptake, higher ventilation, respiratory rate, blood pressure, and Borg scores (p < 0.05) when contrasted with controls, as expected. However, no significant differences were found for HRV indexes between groups (p > 0.05). In addition, WB-EMS did not increase oxygen uptake or altered autonomic modulation when contrasted with sham in both groups (p < 0.05). Conclusion: Obesity has a negative impact on symptoms and functional capacity. However, WB-EMS did not acutely enhance oxygen uptake or HRV during exercise in a population with obesity.

Inspiratory Muscle Training Improves Aerobic Capacity in Amateur Indoor Football Players.

Inspiratory muscle training represents a recommended clinical practice to improve physical performance of healthy individuals, athletes, and those with chronic diseases. This study aimed to evaluate whether high- and low-intensity inspiratory muscle training interferes with the aerobic capacity of indoor soccer players. Volunteers were equally and randomly divided into CON (control group, no inspiratory muscle training); HIG (high-intensity group, inspiratory muscle training at 80% of maximal inspiratory pressure, 3 sets of 12 repetitions); and LIG (low-intensity group, inspiratory muscle training at 50% of maximal inspiratory pressure, 2 sets of 20 repetitions). Before and after inspiratory muscle training, maximal inspiratory and expiratory pressures, the incremental shuttle run test, and the 3-min step test were evaluated. Both inspiratory muscle training protocols improved maximal inspiratory and expiratory pressures, and indirect maximal oxygen consumption and distance traveled in the shuttle test compared to CON. However, only HIG achieved significant increases of indirect oxygen consumption and frequency of step rise in the 3-min step test (p<0.05). Inspiratory muscle training is an important tool to enhance maximal inspiratory pressure and exercise tolerance with potential benefits on submaximal aerobic capacity. However, high-intensity inspiratory muscle training improved aerobic capacity in amateur indoor soccer players in both submaximal tests.

Effects of Whole-Body Electromyostimulation Associated with Dynamic Exercise on Functional Capacity and Heart Rate Variability After Bariatric Surgery: a Randomized, Double-Blind, and Sham-Controlled Trial.

PURPOSE: Bariatric surgery is the most effective treatment for morbid obesity. In association with dietary restrictions, the ability to exercise in the immediate post-surgical phase is limited. In this context, whole-body electromyostimulation (WB-EMS), strategy that stimulates various muscle groups, in conjunction with physical exercise, holds promise for improving functional capacity, and cardiac autonomic control, following surgery. The purpose of this study was to analyze whether a rehabilitation program consisting of WB-EMS with 30 exercise training sessions following bariatric surgery significantly improves functional capacity, body mass and heart rate variability (HRV). METHODS: Randomized, double-blind, and sham-controlled trial. Twenty obesity patients were randomized into the WB-EMS (n = 10) and sham (n = 10) groups. On average, 7 days after surgery, individuals underwent a six-minute walk test (6MWT), HRV, and body composition analysis at rest. The next day, patients initiated an exercise training protocol, five times per week, over 6 weeks. Walking distance changes (post-pre = ΔWD) obtained by 6MWT and HRV indices were determined following the intervention. RESULTS: Only WB-EMSG significantly increased WD and body mass index (BMI) after the intervention (p = 0.002) and ΔWD was significantly higher in this group when compared with sham (p = 0.04). Moreover, both groups demonstrated an improvement in key measures of HRV after the intervention. CONCLUSION: An exercise training intervention initiated shortly after bariatric surgery improved functional capacity and cardiac autonomic tone. Improvements in functional capacity and BMI following exercise training were greater with the addition of WB-EMS but did not promote additional improvements in HRV beyond that realized with exercise training alone.

Physical Exercise Combined With CPAP in Subjects Who Underwent Surgical Myocardial Revascularization: A Randomized Clinical Trial.

BACKGROUND: Aerobic exercise and CPAP benefit patients in the postoperative period of cardiac surgery. To our knowledge, the association of aerobic exercise on an exercise bicycle with CPAP has not yet been demonstrated. Therefore, we aimed to evaluate the effectiveness of physical exercise on a cycle ergometer combined with CPAP in the postoperative period after coronary artery bypass graft surgery. METHODS: This was a randomized clinical trial, with recruitment from May 2017 to December 2017 (registered in the Brazilian Clinical Trials Registry: RBR-69CDYF). The step group (n = 16 subjects) started rehabilitation in the immediate postoperative period with breathing exercises and passive mobilization in the sitting position, progressing to active exercises, ambulation, and stair training. For the intervention group (n = 15 subjects), dynamic exercises on a cycle ergometer combined with CPAP were added to the step program from the second to the fourth postoperative day in a single daily session. RESULTS: Functional capacity decreased in both groups, but this reduction was not significant in the intervention group (P = .11). The length of stay in ICU was lower in the intervention group (P = .050). In both groups there was a decrease in maximum inspiratory and expiratory pressure, as well as in the 1-min sit-to-stand test on the fourth postoperative day compared to the preoperative period. CONCLUSIONS: Physical exercise combined with CPAP promoted the maintenance of functional capacity and reduced the length of stay in the ICU.

Effects of light-emitting diode therapy (LEDT) on cardiopulmonary and hemodynamic adjustments during aerobic exercise and glucose levels in patients with diabetes mellitus: A randomized, crossover, double-blind and placebo-controlled clinical trial.

The aim of this study was to evaluate the acute effects of light-emitting diode therapy (LEDT) on cardiopulmonary adjustments and muscle oxygenation dynamics during transition to moderate exercise, as well as in glucose and lactate levels in patients with type 2 diabetes mellitus (T2DM). Sixteen individuals with T2DM (age 55.1±5.4 years) performed four separate tests receiving LEDT or placebo in random order, at intervals of at least 14 days. A light-emitting diode array (50GaAIAs LEDs, 850nm, 75mW per diode) was used to perform LEDT bilaterally on the quadriceps femoris and triceps surae muscles for 40s at each site. After, a moderate cycling exercise was performed and oxygen uptake, muscular deoxyhemoglobin, heart rate and cardiac output were measured. Lactate and glucose levels were measured before LEDT/placebo and after the exercise. The LEDT decreased the glucose levels after the exercise compared with values before LEDT (173.7±61.0 to 143.5±53.5 mg/dl, P=0.02) and it did not affect the cardiopulmonary and hemodynamic adjustments in exercise, as well as lactate levels in both groups. In conclusion, the LEDT in combination with moderate exercise acutely decreased the glucose levels in men with T2DM.

Functional and systemic effects of whole body electrical stimulation post bariatric surgery: study protocol for a randomized controlled trial.

BACKGROUND: Obesity represents a major public health problem and is the fifth leading risk factor for mortality. Morbid obesity is associated with chronic systemic inflammation which increases the risk of comorbidities. Bariatric surgery (BS) is considered an effective intervention for obese patients. However, BS is associated with dietary restriction, potentially limiting physical activity. Whole-body neuromuscular electrical stimulation (WBS) could represent an innovative option for the rehabilitation of BS patients, especially during the early postoperative phase when other conventional techniques are contraindicated. WBS is a safe and effective tool to combat sarcopenia and metabolic risk as well as increasing muscle mass, producing greater glucose uptake, and reducing the proinflammatory state. Therefore, the objective of this study is to evaluate the effects of WBS on body composition, functional capacity, muscle strength and endurance, insulin resistance, and pro- and anti-inflammatory circulating markers in obese patients undergoing BS. METHODS/DESIGN: The present study is a randomized, double-blind, placebo-controlled, parallel groups clinical trial approved by the Ethics Committee of our Institution. Thirty-six volunteers (body mass index (BMI) > 35 kg/m2) between 18 and 45 years of age will be randomized to the WBS group (WBSG) or control (Sham) group (ShamG) after being submitted to BS. Preoperative assessments will include maximal and submaximal exercise testing, body composition, blood inflammatory markers, and quadriceps strength and endurance. The second day after discharge, body composition will be evaluated and a 6-min walk test (6MWT) will be performed. The WBS or Sham protocol will consist of 30 daily sessions for 6 consecutive weeks. Afterwards, the same assessments that were performed in the preoperative period will be repeated. DISCUSSION: Considering the important role of WBS in skeletal muscle conditioning and its value as an aid in exercise performance, the proposed study will investigate this technique as a tool to promote early rehabilitation in these patients, and as a strategy to enhance exercise capacity, weight loss, and peripheral muscle strength with positive systemic effects. The present study is still ongoing, and data will be published after its conclusion. TRIAL REGISTRATION: REBEC, RBR-99qw5h . Registered on 20 February 2015.

The Effect of 1 Week of a Multi-ingredient Dietary Preworkout Supplement on Resting and Postacute Resistance Exercise Vascular Function.

Dietary preworkout supplements are popular among recreational exercisers and athletes. However, the effects of these supplements on the vasculature, both at rest and during exercise, are not well studied. Therefore, the purpose of this study was to determine the effect of 1 week of supplementation with a multi-ingredient dietary preworkout supplement on measures of vascular function at rest and immediately following acute resistance exercise in young, recreationally active adults. Twelve participants (9 males and 3 females; mean ± SD: age = 24.5 ± 3.4 years and body mass index = 24.3 ± 4.7 kg/m2) completed this double-blind, randomized, crossover design study. After familiarization, participants were randomized to either a taste-matched placebo or the preworkout supplement for 1 week preceding the testing visits. Participants underwent measures of vascular function, including brachial artery flow-mediated dilation, measures of central and peripheral blood pressure, and measures of arterial stiffness via pulse wave analysis and pulse wave velocity. All measures were taken at rest and immediately following an acute bilateral leg press exercise session. Resting and postacute exercise flow-mediated dilation, blood pressure, and arterial stiffness were similar between the placebo and the preworkout supplement visits. One week of multi-ingredient preworkout supplementation does not affect vascular function at rest or in response to an acute bout of resistance exercise in young, healthy, recreationally active individuals.

Neuromuscular electrical stimulation improves exercise tolerance in patients with advanced heart failure on continuous intravenous inotropic support use-randomized controlled trial.

OBJECTIVE: To evaluate the impact of a short-term neuromuscular electrical stimulation program on exercise tolerance in hospitalized patients with advanced heart failure who have suffered an acute decompensation and are under continuous intravenous inotropic support. DESIGN: A randomized controlled study. SUBJECTS: Initially, 195 patients hospitalized for decompensated heart failure were recruited, but 70 were randomized. INTERVENTION: Patients were randomized into two groups: control group subject to the usual care ( n = 35); neuromuscular electrical stimulation group ( n = 35) received daily training sessions to both lower extremities for around two weeks. MAIN MEASURES: The baseline 6-minute walk test to determine functional capacity was performed 24 hours after hospital admission, and intravenous inotropic support dose was daily checked in all patients. The outcomes were measured in two weeks or at the discharge if the patients were sent back home earlier than two weeks. RESULTS: After losses of follow-up, a total of 49 patients were included and considered for final analysis (control group, n = 25 and neuromuscular electrical stimulation group, n = 24). The neuromuscular electrical stimulation group presented with a higher 6-minute walk test distance compared to the control group after the study protocol (293 ± 34.78 m vs. 265.8 ± 48.53 m, P < 0.001, respectively). Neuromuscular electrical stimulation group also demonstrated a significantly higher dose reduction of dobutamine compared to control group after the study protocol (2.72 ± 1.72 µg/kg/min vs. 3.86 ± 1.61 µg/kg/min, P = 0.001, respectively). CONCLUSION: A short-term inpatient neuromuscular electrical stimulation rehabilitation protocol improved exercise tolerance and reduced intravenous inotropic support necessity in patients with advanced heart failure suffering a decompensation episode.

Effects of inspiratory muscle training in professional women football players: a randomized sham-controlled trial.

This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.

Effects of phototherapy plus physical training on metabolic profile and quality of life in postmenopausal women.

A cluster of metabolic abnormalities are markedly higher among postmenopausal women. The present study evaluated the effects of infrared light emitting diode (LED) during treadmill training on multiple metabolic markers, body fat, dietary habits and quality of life in postmenopausal women. Forty-five postmenopausal women aged 50-60 years were randomly assigned to one of three groups, and of these, 30 women successfully completed the full study. The three groups were as follows: (i) the LED group, which performed treadmill training associated with phototherapy (n = 10); (ii) the exercise group, which carried out treadmill training only (n = 10); and (iii) the sedentary group, which neither performed physical training nor underwent phototherapy (n = 10). Training was performed over a period of six months, twice a week for 45 min per session at 85-90% of maximal heart rate (HRmax), which was obtained during a progressive exercise testing. The average HR and velocity during treadmill training were 144 ± 9 bpm and 5.8 ± 1.3 km/h for both trained groups. The irradiation parameters were 100 mW, 39 mW/cm2 and 108 J/cm2 for 45 min. Anthropometric data, skinfolds thickness, biochemical exams (lipid profile, glucose and insulin levels), dietary habits and quality of life were evaluated. The sum of skinfolds significantly improved in the exercise and sedentary groups (p < 0.05). Additionally, there was an improvement in lipid profile, particularly, total cholesterol and low-density lipoprotein, which reduced significantly for all groups (p ˂ 0.05). However, intake of saturated fats was significantly reduced in the sedentary group only (p < 0.05). The quality of life improved in the LED group only, with a significant reduction in the total WHQ score (p < 0.05). Physical training with or without phototherapy may improve the metabolic profile. In addition, phototherapy together with treadmill training prevented an increase in subcutaneous fat and facilitated an improved quality of life in postmenopausal women.

Respiratory Muscle Training Improves Diaphragm Citrate Synthase Activity and Hemodynamic Function in Rats with Heart Failure.

INTRODUCTION:: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE:: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS:: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS:: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION:: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Respiratory muscle training improves diaphragm citrate synthase activity and hemodynamic function in rats with heart failure

Abstract INTRODUCTION: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Respiratory Muscle Training Improves Chemoreflex Response, Heart Rate Variability, and Respiratory Mechanics in Rats With Heart Failure.

BACKGROUND: The aim of the present report was to evaluate respiratory muscle training (RMT) effects on hemodynamic function, chemoreflex response, heart rate variability, and respiratory mechanics in rats with heart failure (HF rats). METHODS: Wistar rats were divided into 4 groups: sedentary-sham (Sed-Sham, n = 8), respiratory muscle trained-sham (RMT-Sham, n = 8), sedentary-HF (Sed-HF, n = 8) and respiratory muscle trained-HF (RMT-HF, n = 8). Animals were submitted to an RMT protocol performed 30 minutes per day, 5 days per week for 6 weeks, whereas the sedentary animals did not exercise. RESULTS: In HF rats, RMT promoted the reduction of left ventricular end-diastolic pressure, right ventricular hypertrophy, and pulmonary edema. Moreover, RMT produced a reduction in pressure response during chemoreflex activation, sympathetic modulation, and sympathetic vagal balance in addition to an increase in parasympathetic modulation. Also after RMT, HF rats demonstrated a reduction in respiratory system resistance, tissue resistance, Newtonian resistance, respiratory system compliance, and quasistatic compliance. CONCLUSIONS: These findings suggested that 6 weeks of RMT in HF rats promoted beneficial adaptations in hemodynamics, autonomic function, and respiratory mechanics and attenuated pressure response evoked by chemoreflex activation in HF rats.

Acute effects of low-level laser therapy irradiation on blood lactate and muscle fatigue perception in hospitalized patients with heart failure-a pilot study.

The objective of the present study is to evaluate the acute effects of low-level laser therapy (LLLT) on functional capacity, perceived exertion, and blood lactate in hospitalized patients with heart failure (HF). Patients diagnosed with systolic HF (left ventricular ejection fraction <45 %) were randomized and allocated prospectively into two groups: placebo LLLT group (n = 10)-subjects who were submitted to placebo laser and active LLLT group (n = 10)-subjects who were submitted to active laser. The 6-min walk test (6MWT) was performed, and blood lactate was determined at rest (before LLLT application and 6MWT), immediately after the exercise test (time 0) and recovery (3, 6, and 30 min). A multi-diode LLLT cluster probe (DMC, São Carlos, Brazil) was used. Both groups increased 6MWT distance after active or placebo LLLT application compared to baseline values (p = 0.03 and p = 0.01, respectively); however, no difference was observed during intergroup comparison. The active LLLT group showed a significant reduction in the perceived exertion Borg (PEB) scale compared to the placebo LLLT group (p = 0.006). In addition, the group that received active LLLT showed no statistically significant difference for the blood lactate level through the times analyzed. The placebo LLLT group demonstrated a significant increase in blood lactate between the rest and recovery phase (p < 0.05). Acute effects of LLLT irradiation on skeletal musculature were not able to improve the functional capacity of hospitalized patients with HF, although it may favorably modulate blood lactate metabolism and reduce perceived muscle fatigue.

High-Intensity Inspiratory Protocol Increases Heart Rate Variability in Myocardial Revascularization Patients.

OBJECTIVE: To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting. METHODS: Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values. RESULTS: Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P <0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P <0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition. CONCLUSION: These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.

Hippotherapy acute impact on heart rate variability non-linear dynamics in neurological disorders.

Neurological disorders are associated with autonomic dysfunction. Hippotherapy (HT) is a therapy treatment strategy that utilizes a horse in an interdisciplinary approach for the physical and mental rehabilitation of people with physical, mental and/or psychological disabilities. However, no studies have been carried out which evaluated the effects of HT on the autonomic control in these patients. Therefore, the objective of the present study was to investigate the effects of a single HT session on cardiovascular autonomic control by time domain and non-linear analysis of heart rate variability (HRV). The HRV signal was recorded continuously in twelve children affected by neurological disorders during a HT session, consisting in a 10-minute sitting position rest (P1), a 15-minute preparatory phase sitting on the horse (P2), a 15-minute HT session (P3) and a final 10-minute sitting position recovery (P4). Time domain and non-linear HRV indices, including Sample Entropy (SampEn), Lempel-Ziv Complexity (LZC) and Detrended Fluctuation Analysis (DFA), were calculated for each treatment phase. We observed that SampEn increased during P3 (SampEn=0.56±0.10) with respect to P1 (SampEn=0.40±0.14, p<0.05), while DFA decreased during P3 (DFA=1.10±0.10) with respect to P1 (DFA=1.26±0.14, p<0.05). A significant SDRR increase (p<0.05) was observed during the recovery period P4 (SDRR=50±30ms) with respect to the HT session period P3 (SDRR=30±10ms). Our results suggest that HT might benefit children with disabilities attributable to neurological disorders by eliciting an acute autonomic response during the therapy and during the recovery period.

High-Intensity Inspiratory Protocol Increases Heart Rate Variability in Myocardial Revascularization Patients

Abstract Objective: To evaluate heart rate variability during an inspiratory muscle endurance protocol at three different load levels [30%, 60% and 80% of maximal inspiratory pressure], in patients who had previously undergone coronary artery bypass grafting. Methods: Nineteen late postoperative myocardial revascularization patients participating in a cardiovascular rehabilitation program were studied. Maximal inspiratory pressure maneuvers were performed. An inspiratory muscle endurance protocol at 30%, 60% and 80% of maximal inspiratory pressure was applied for four minutes each, in random order. Heart rate and RR intervals were recorded and heart rate variability was analyzed by time (RMSSD-the mean of the standard deviations for all R-R intervals, and RMSM-root-mean square differences of successive R-R intervals) and frequency domains indices (high and low frequency) in normalized units. ANOVA for repeated measurements was used to compare heart rate variability indices and Student t-test was used to compare the maximal inspiratory pressure and maximal expiratory pressure values. Results: Heart rate increased during performance of maximal respiratory pressures maneuvers, and the maximal inspiratory pressure and maximal expiratory pressure mean values were significantly lower than predicted values (P <0.05). RMSSD increased significantly at 80% in relation to rest and 30% of maximal inspiratory pressure and RMSM decreased at 30% and 60% of maximal inspiratory pressure in relation to rest (P <0.05). Additionally, there was significant and progressive decrease in low frequency and increase in high frequency at 30%, 60% and 80% of maximal inspiratory pressure in relation to the resting condition. Conclusion: These results suggest that respiratory muscle training at high intensities can promote greater parasympathetic activity and it may confer important benefits during a rehabilitation program in post-coronary artery bypass grafting.

Does exercise ventilatory inefficiency predict poor outcome in heart failure patients with COPD?

To investigate whether the opposite effects of heart failure (HF) and chronic obstructive pulmonary disease (COPD) on exercise ventilatory inefficiency (minute ventilation [(Equation is included in full-text article.)E]-carbon dioxide output [(Equation is included in full-text article.)CO2] relationship) would negatively impact its prognostic relevance. METHODS: After treatment optimization and an incremental cardiopulmonary exercise test, 30 male patients with HF-COPD (forced expiratory volume in 1 second [FEV1] = 57% ± 17% predicted, ejection fraction = 35% ± 6%) were prospectively followed up during 412 ± 261 days for major cardiac events.RESULTS:Fourteen patients (46%) had a negative outcome. Patients who had an event had lower echocardiographically determined right ventricular fractional area change (RVFAC), greater ventilatory inefficiency (higher (Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2 nadir), and lower end-tidal CO2 (PETCO2) (all P 36, ΔPETCO2(PEAK-REST)≥2 mm Hg, and PETCO2PEAK≤33 mm Hg added prognostic value to RVFAC≤45%. Kaplan-Meyer analyses showed that although 18% of patients with RVFAC>45% had a major cardiac event after 1 year, no patient with RVFAC>45% and (Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2 nadir ≤36 (or PETCO2PEAK>33 mm Hg) had a negative event. Conversely, although 69% of patients with RVFAC≤45% had a major cardiac event after 1 year, all patients with RVFAC≤45% and ΔPETCO2(PEAK-REST)≥2 mm Hg had a negative event...

Evaluation of acute effect of light-emitting diode (LED) phototherapy on muscle deoxygenation and pulmonary oxygen uptake kinetics in patients with diabetes mellitus: study protocol for a randomized controlled trial.

BACKGROUND: Type 2 diabetes mellitus (DM) is responsible for a significant reduction in the quality of life due to its negative impact on functional capacity. Cardiopulmonary fitness impairment in DM patients has been associated with limited tissue oxygenation. Phototherapy is widely utilized to treat several disorders due to expected light-tissue interaction. This type of therapy may help to improve muscular oxygenation, thereby increasing aerobic fitness and functional capacity. METHODS/DESIGN: This study is a randomized, double-blind, placebo-controlled crossover trial approved by the Ethics Committee of the Federal University of São Carlos and registered at ClinicalTrials.gov. Four separate tests will be performed to evaluate the acute effect of phototherapy. All participants will receive both interventions in random order: light-emitting diode therapy (LEDT) and placebo, with a minimum 14-day interval between sessions (washout period). Immediately after the intervention, participants will perform moderate constant workload cycling exercise corresponding to 80 % of the pulmonary oxygen uptake [Formula: see text] during the gas exchange threshold (GET). LEDT will be administered with a multidiode cluster probe (50 GaAIA LEDs, 850 ηm, 75 mW each diode, and 3 J per point) before each exercise session. Pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure will be measured using a computerized metabolic cart, a near-infrared spectrometer, an electrocardiogram, and a photoplethysmography system, respectively. DISCUSSION: The main objective of this study is to evaluate the acute effects of muscular pre-conditioning using LED phototherapy on pulmonary oxygen uptake, muscle oxygenation, heart rate, and arterial pressure dynamics during dynamic moderate exercise. We hypothesize that phototherapy may be beneficial to optimize aerobic fitness in the DM population. Data will be published after the study is completed. TRIAL REGISTRATION: Registered at ClinicalTrials.gov under trial number NCT01889784 (date of registration 5 June 2013).