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Grape seed extract (GSE) or L-citrulline supplement has been known to increase nitric oxide (NO) bioavailability and enhance endothelial-mediated vasodilation. Accordingly, to examine the additive benefits of combination of the two supplementations on hemodynamic responses to dynamic exercise, young, healthy males were recruited for this study. Effects of 7 days of 1) GSE + L-citrulline, 2) GSE, 3) L-citrulline, and 4) placebo supplementation on systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), cardiac output, total vascular conductance (TVC), and oxygen (O2) consumption were examined at rest and during cycling exercise. Compared with placebo, GSE, L-citrulline, and combined supplementations did not reduce SBP, DBP, and MAP, while cardiac output (placebo; 23.6 ± 1.3 L/min, GSE; 25.7 ± 1.1 L/min; L-citrulline, 25.2 ± 1.2 L/min; GSE + L-citrulline; 25.3 ± 0.9 L/min) and TVC (placebo; 234.7 ± 11.3 ml/min/mmHg, GSE; 258.3 ± 10.6 ml/min/mmHg; L-citrulline, 255.2 ± 10.6 ml/min/mmHg; GSE + L-citrulline; 260.4 ± 8.9 ml/min/mmHg) were increased at only the 80% workload (p < 0.05). Compared with placebo and L-citrulline, GSE and combined supplementations had a reduction in VO2 across workloads (p < 0.05). However, there was no additive benefits on these variables. We conclude that supplementation with GSE, L-citrulline, and combined supplementations increased cardiac output due partially to decreased vascular resistance. Our findings suggest that GSE may act as an ergogenic aid that can improve O2 delivery to exercising muscles. [ABSTRACT FROM AUTHOR]

The accumulation of lactate in muscle and blood during high-intensity exercise is negatively correlated with the duration exercise can be sustained. Removal of lactate is a key component of acute recovery between consecutive bouts of such exercise. Low-intensity exercise enhances recovery by accelerating lactate turnover in metabolically active tissues, largely mediated by blood flow to these tissues. Therefore, the purpose of this research was to clarify if L-citrulline, a nutritional supplement purported to promote vasodilation via enhanced nitric oxide availability, would augment the removal of blood lactate during active recovery (AR). L-citrulline ingestion will augment the rate of blood lactate concentration decrease during AR, reduce the oxygen-cost of submaximal exercise, and increase time-to-exhaustion and peak oxygen uptake (V̇O2peak) during a test of maximal aerobic power. Healthy university students (five males & five females) participated in this double-blind, randomized, placebo-controlled study. Participants exercised on a cycle ergometer at submaximal steady-state intensities followed by progressively increasing intensity to exhaustion, 10 min of AR, and then supramaximal intensity exercise to exhaustion. Oxygen uptake was measured throughout the trial and blood lactate was sampled repeatedly during AR. The protocol elicited very high peak blood lactate concentrations after exercise (11.3 + 1.3 mmol/L). L-citrulline supplementation did not significantly alter blood lactate kinetics during AR, the oxygen cost of exercise, V̇O2peak, or time-to-exhaustion. Despite a strong theoretical basis by which L-citrulline could augment lactate removal from the blood, L-citrulline supplementation showed no effect as an exercise-recovery supplement. [ABSTRACT FROM AUTHOR]

This investigation assessed the psycho-physiological and performance effects of hot water immersion (HWI) implemented either before or after a repeated-sprint training in hypoxia (RSH) session conducted in the heat. Ten participants completed three RSH trials (3 × 10 × 5-s sprints), conducted at 40°C and simulated altitude of 3000 m. A 30-min monitoring period preceded and followed all exercise sessions. In PRE, the pre-exercise period was HWI, and the post-exercise period was seated rest in temperate conditions. This combination was reversed in POST. In CON, participants were seated in temperate conditions for both periods. Compared to CON, PRE elicited a reduction in power output during each repeated-sprint set (14.8–16.2%, all p < 0.001), and a significantly higher core temperature (Tc) during the pre-exercise period and throughout the exercise session (p < 0.001 and p = 0.025, respectively). In POST, power output and Tc until the end of exercise were similar to CON, with Tc higher at the conclusion of the post-exercise period (p < 0.001). Time across the entire protocol spent ≥38.5°C Tc was significantly longer in PRE (48.1 ± 22.5 min) than POST (31.0 ± 11.3 min, p = 0.05) and CON (15.8 ± 16.3 min, p < 0.001). Employing HWI following RSH conducted in the heat provides effective outcomes regarding physiological strain and cycling performance when compared to pre-exercise or no HWI. [ABSTRACT FROM AUTHOR]

Background: Few studies have demonstrated the suppressive effects of amino acids (AAs) on the level of cortisol during exercise in humans. We hypothesized that an AA mixture containing arginine, which promotes lipid metabolism, valine, which effectively decreases the level of glucocorticoid, and serine, a substrate in the production of phosphatidylserine that is reported to blunt increases in cortisol, would suppress the exercise-induced cortisol response by combining the positive effects of the AAs synergistically. Methods: A randomized, double-blinded, placebo-controlled crossover trial was conducted. Twenty healthy recreationally active males ingested either an AA mixture containing 1.8 g of arginine, 1.1 g of valine, and 0.1 g of serine or a placebo. Thirty minutes after ingestion, subjects performed an exercise trial on a cycle ergometer for 80 min at 50% maximal oxygen consumption. Plasma cortisol and other blood parameters immediately before and after the exercise were evaluated. Results: Plasma cortisol concentrations after exercise were significantly higher than those before exercise in the placebo condition (9.51 ± 0.85 vs 14.39 ± 2.15, p < 0.05), while there was no significant difference in the AA condition (9.71 ± 0.93 vs 9.99 ± 1.23, p = 0.846). In addition, the increase in plasma cortisol before and after exercise was significantly lower in the AA condition than in the placebo condition (0.28 [− 2.75, 3.31] vs 4.87 [0.89, 8.86], p < 0.05). For the level of adrenocorticotropin, there was a significant difference between before and after exercise only in the placebo condition (24.21 ± 2.91 vs 53.17 ± 6.97, p < 0.01) but not in the AA condition (27.33 ± 3.60 vs 46.92 ± 10.41, p = 0.057). Blood glucose, plasma lactate, plasma ammonia, serum creatine phosphokinase, serum total ketone body, and serum free fatty acid were also significantly changed by the exercise load in both conditions, but no significant differences were observed between the two conditions. Conclusions: The present study demonstrated that the AA mixture suppressed the cortisol response during exercise without affecting exercise-related biological parameters such as glucose or lipid metabolism. Trial registration: UMIN Clinical Trials Registry, UMIN000023587. Registered 19 August 2016. [ABSTRACT FROM AUTHOR]

While right heart catheterization (RHC) at rest is the gold standard to assess pulmonary hemodynamics in patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension (PH), the invasive measurement of exercise hemodynamics is less well established in this group. Since exercise hemodynamics are increasingly recognized as important clinical information in patients with PH, our goal was to review the literature in this field to provide a basis for clinical use, further studies, and future recommendations. We identified 69 studies (published since 1968) reporting RHC data in 2819 patients with COPD, of whom 2561 underwent exercise testing. Few studies simultaneously measured gas exchange during exercise. Overall, these studies showed large variations in the patient populations and research questions studied and the methods and definitions employed. Despite these limitations, the data consistently demonstrated the presence of precapillary PH at rest in up to 38% of patients with COPD. With exercise, a relevant proportion of patients developed an abnormal hemodynamic response, depending on the definition used. Furthermore, some studies assessed right ventricular function during exercise and showed a blunted increase in right ventricular ejection fraction. Drug effects and the impact of interventional procedures were also studied. Again, due to large variations in the patients studied and the methods used, firm conclusions are difficult to derive. Despite the limitations of this dataset, several recommendations with respect to technical aspects (body position, exercise protocol, and data acquisition) can be inferred for this challenging patient population and may be helpful for further studies or recommendations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate two practical interval training protocols on cardiorespiratory fitness, lipids and body composition in overweight/obese women. Thirty women (mean ± SD; weight: 88.1 ± 15.9 kg; BMI: 32.0 ± 6.0 kg . m2) were randomly assigned to ten 1-min high-intensity intervals (90%VO2 peak, 1 min recovery) or five 2-min high-intensity intervals (80–100% VO2 peak, 1 min recovery) or control. Peak oxygen uptake (VO2 peak), peak power output (PPO), body composition and fasting blood lipids were evaluated before and after 3 weeks of training, completed 3 days per week. Results from ANCOVA analyses demonstrated no significant training group differences for any primary variables (P > 0.05). When training groups were collapsed, 1MIN and 2MIN resulted in a significant increase in PPO (Δ18.9 ± 8.5 watts; P = 0.014) and time to exhaustion (Δ55.1 ± 16.4 s; P = 0.001); non-significant increase in VO2 peak (Δ2.36 ± 1.34 ml . kg-1 . min-1; P = 0.185); and a significant decrease in fat mass (FM) (−Δ1.96 ± 0.99 kg; P = 0.011). Short-term interval exercise training may be effective for decreasing FM and improving exercise tolerance in overweight and obese women. [ABSTRACT FROM AUTHOR]

Individuals with schizophrenia have a greater risk for cardiometabolic risk factors (e.g. central obesity, insulin resistance, hypertension and dyslipidaemia), cardiovascular diseases and mortality. This risky profile may be explained by the adverse effects of antipsychotic medications and an unhealthy lifestyle (e.g. smoking, poor nutrition and low physical activity). In the general population, physical activity has been shown to be the optimal strategy to improve both cardiometabolic parameters and cardiorespiratory fitness levels. Accordingly, an emerging literature of non-pharmacological interventions (e.g. cognitive behavioural therapy, diet and physical activity) has been studied in individuals with schizophrenia. Therefore, the purpose of this review was 1) to conduct a critical literature review of non-pharmacological interventions that included some kind of physical activity (including supervised and unsupervised exercise training) and target cardiometabolic risk factors in individuals with schizophrenia. 2) To describe the contribution of physical activity alone by reviewing trials of supervised exercise training programmes only. A literature review via systematic keyword search for publications in Medline, PubMed, Embase and PsycINFO was performed. Many non-pharmacological interventions are efficient in reducing cardiovascular disease risk factors when combined with physical activity. Supervised physical activity has been successful in decreasing cardiovascular disease risk, and aerobic interval training appears to provide more benefits by specifically targeting cardiorespiratory fitness levels. In conclusion, physical activity is an effective strategy for addressing cardiovascular disease risk in individuals with schizophrenia. Long-term studies are needed to evaluate the feasibility and impact of exercise training programmes in individuals with schizophrenia. [ABSTRACT FROM AUTHOR]

Background Almonds are a healthy tree nut food with high nutrient density. Their consumption has been shown to ameliorate oxidative stress, inflammation, etc. The objective of the study was to examine the effect of almonds on elements of endurance exercise performance in trained athletes. Methods A 10-week crossover, placebo controlled study was conducted. Eight trained male cyclists and two triathletes were randomly assigned to consume 75 g/d whole almonds (ALM) or isocaloric cookies (COK) with equal subject number. They consumed the assigned food for 4 wks and then the alternate food for another 4 wks. They underwent 3 performance tests including 125-min steady status exercise (SS) and 20-min time trial (TT) on an indoor stationary trainer at the start of the study (BL) and at the end of each intervention phase. Venous blood was collected in the morning prior to the performance test for biochemical measurements and finger blood during the test for glucose determination. Carbohydrate and fat oxidation, energy expenditure, and oxygen use were calculated using respiratory gas analysis. Results ALM increased cycling distance during TT by 1.7 km as compared BL (21.9 vs. 20.2 km, P = 0.053) and COK increased 0.6 km (20.8 vs. 20.2 km, P > 0.05). ALM, but not COK, led to higher CHO and lower fat oxidation and less oxygen consumption during TT than BL (P < 0.05), whereas there was no significant difference in heart rate among BL, ALM and COK. ALM maintained higher blood glucose level after TT than COK (P < 0.05). ALM had higher vitamin E and haemoglobin and lower serum free fatty acid (P < 0.05), slightly elevated serum arginine and nitric oxide and plasma insulin (P > 0.05) than BL, and a higher total antioxidant capacity than COK (P < 0.05). Conclusions Whole almonds improved cycling distance and the elements related to endurance performance more than isocaloric cookies in trained athletes as some nutrients in almonds may contribute to CHO reservation and utilization and effective oxygen utilization. The results suggest that almonds can be incorporated into diets of those who undertake exercise training for performance improvement. [ABSTRACT FROM AUTHOR]

Background: Exercise is an excellent tool to study the interactions between metabolic stress and the immune system. Specifically, high-intensity exercises both produce transient hyperammonemia and influence the distribution of white blood cells. Carbohydrates and glutamine and arginine supplementation were previously shown to effectively modulate ammonia levels during exercise. In this study, we used a short-duration, high-intensity exercise together with a low carbohydrate diet to induce a hyperammonemia state and better understand how arginine influences both ammonemia and the distribution of leukocytes in the blood. Methods: Brazilian Jiu-Jitsu practitioners (men, n = 39) volunteered for this study. The subjects followed a lowcarbohydrate diet for four days before the trials and received either arginine supplementation (100 mgkg-1 of body massday-1) or a placebo. The intergroup statistical significance was calculated by a one-way analysis of variance, followed by Student’s t-test. The data correlations were calculated using Pearson’s test. Results: In the control group, ammonemia increased during matches at almost twice the rate of the arginine group (25 mmolL-1min-1 and 13 μmolL-1min-1, respectively). Exercise induced an increase in leukocytes of approximately 75%. An even greater difference was observed in the lymphocyte count, which increased 2.2-fold in the control group; this increase was partially prevented by arginine supplementation. The shape of the ammonemia curve suggests that arginine helps prevent increases in ammonia levels. Conclusions: These data indicate that increases in lymphocytes and ammonia are simultaneously reduced by arginine supplementation. We propose that increased serum lymphocytes could be related to changes in ammonemia and ammonia metabolism. [ABSTRACT FROM AUTHOR]

Eccentric cycling may present an interesting alternative to traditional exercise rehabilitation for patients with advanced COPD, because of the low ventilatory cost associated with lengthening muscle actions. However, due to muscle damage and soreness typically associated with eccentric exercise, there has been reluctance in using this modality in clinical populations. This study assessed the feasibility of applying an eccentric cycling protocol, based on progressive muscle overload, in six severe COPD patients with the aim of minimizing side effects and maximizing compliance. Over 5 weeks, eccentric cycling power was progressively increased in all patients from a minimal 10-Watt workload to a target intensity of 60%% peak oxygen consumption (attained in a concentric modality). By 5 weeks, patients were able to cycle on average at a 7-fold higher power output relative to baseline, with heart rate being maintained at ∼85%% of peak. All patients complied with the protocol and presented tolerable dyspnea and leg fatigue throughout the study; muscle soreness was minimal and did not compromise increases in power; creatine kinase remained within normal range or was slightly elevated; and most patients showed a breathing reserve > 15 L.min−1. At the target intensity, ventilation and breathing frequency during eccentric cycling were similar to concentric cycling while power was approximately five times higher (p == 0.02). This study showed that an eccentric cycling protocol based on progressive increases in workload is feasible in severe COPD, with no side effects and high compliance, thus warranting further study into its efficacy as a training intervention. [ABSTRACT FROM AUTHOR]

Mechanisms underlying the relationship between exercise and mood are not well understood. This study sought to investigate the role of pro- and anti-inflammatory cytokines and autonomic balance in determining the impact of exercise withdrawal on negative mood. Healthy men and women who regularly exercised ( N  ==  26, mean age  ==  25.5 years, SD  ==  4.5 years) were randomised to exercise withdrawal or exercise maintenance for 2 weeks. Protocol adherence was monitored using accelerometers. Inflammatory markers from plasma (interleukin-6, IL-6; tumour necrosis factor-alpha; interleukin-10; and interleukin-1 receptor antagonist), heart-rate variability (HRV) and measures of mood (General Health Questionnaire-28 (GHQ) and the Profile of Mood States (POMS)) were assessed at study entry and at 2-week follow-up. Exercise withdrawal resulted in significant increases in negative mood over time on both the GHQ ( p  ==  0.028) and the POMS ( p  ==  0.005). Following the intervention, IL-6 concentration was lower in the exercise withdrawal than exercise maintenance condition ( p  ==  0.05). No intervention effects were observed for other cytokines or HRV. The mood changes were significantly related to changes in IL-6 concentration (ββ  ==  −−  0.50, p  ==  0.011), indicating that reduction in IL-6 was related to increased negative mood. Our results are consistent with positive effects of exercise on mental health, but further research on inflammatory pathways is warranted. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults. [ABSTRACT FROM PUBLISHER]

Objectives To examine whether physical-activity patterns over a period of 4 years are associated with well-being. Design A sample of 399 women aged 50-60 years participated in the study. Measures included rate of physical activity and other life style behaviors, well-being, health status, and interpersonal stress. Sufficient and insufficient exercisers were identified, and the association of this dichotomy with well-being, along with the contribution of the other variables, was examined. Results The distribution of physical-activity patterns remained stable over the 4 years of the study, with 40% of the women exercising leisurely and 15-20% exercising vigorously four to seven times a week. Approximately 50% of the women were considered sufficiently active in terms of public recommendations. Random effects regression analysis revealed that sufficient exercise along with a low frequency of daily hassles, relatively few menopausal symptoms, and a low level of interpersonal stress significantly contributed to the variability of well-being. Conclusions These data evoke the need for a better understanding of exercise behavior and its promising potential contribution to the well-being of middle-aged women. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effects of a realistic, feasible, and commonly used fitness training programme on cardiac autonomic control in 14 sedentary men aged 62.0 ± 6.1 years (mean ± s). All participants performed a one-year fitness training programme in which training intensity and frequency were specifically chosen to be compliant for the majority of the participants (2 – 3 sessions per week at moderate intensity). At the same time, a reference group consisting of 15 sedentary age-matched men (age 64.2 ± 6.5 years) did not change their habitual physical activity. Measurements were performed before and after the training intervention. Cardiac autonomic control was inferred from resting values (supine and standing) of heart rate variability (HRV) computed in the frequency domain over 10-min intervals. Endurance capacity was evaluated during a maximal incremental bicycle ergometer test. In spite of an increase in peak oxygen consumption ([Vdot]O2peak) by 6.4% after training, heart rate in the training group remained unchanged at rest and at the same metabolic demand. No changes in resting parameters of HRV were shown for either groups or positions. Results from this study provide no evidence of a clinically meaningful increase in the vagal modulation to the sinus node at rest after one year of low-volume and moderate-intensity fitness training in men aged 55 – 75 years. [ABSTRACT FROM AUTHOR]