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Ergogenic effects of beetroot juice supplementation during severe-intensity exercise in obese adolescents.
Rasica, L, Porcelli, S, Marzorati, M, Salvadego, D, Vezzoli, A, Agosti, F, De Col, A, Tringali, G, Jones, AM, Sartorio, A, et al
American journal of physiology. Regulatory, integrative and comparative physiology. 2018;(3):R453-R460
Abstract
Previous studies showed a higher O2 cost of exercise, and therefore, a reduced exercise tolerance in patients with obesity during constant work rate (CWR) exercise compared with healthy subjects. Among the ergogenic effects of dietary nitrate ([Formula: see text]) supplementation in sedentary healthy subjects, a reduced O2 cost and enhanced exercise tolerance have often been demonstrated. The aim of this study was to evaluate the effects of beetroot juice (BR) supplementation, rich in [Formula: see text], on physiological variables associated with exercise tolerance in adolescents with obesity. In a double-blind, randomized crossover study, 10 adolescents with obesity (8 girls, 2 boys; age = 16 ± 1 yr; body mass index = 35.2 ± 5.0 kg/m2) were tested after 6 days of supplementation with BR (5 mmol [Formula: see text] per day) or placebo (PLA). Following each supplementation period, patients carried out two repetitions of 6-min moderate-intensity CWR exercise and one severe-intensity CWR exercise until exhaustion. Plasma [Formula: see text] concentration was significantly higher in BR versus PLA (108 ± 37 vs. 15 ± 5 μM, P < 0.0001). The O2 cost of moderate-intensity exercise was not different in BR versus PLA (13.3 ± 1.7 vs. 12.9 ± 1.1 ml·min-1·W-1, P = 0.517). During severe-intensity exercise, signs of a reduced amplitude of the O2 uptake slow component were observed in BR, in association with a significantly longer time to exhaustion (561 ± 198 s in BR vs. 457 ± 101 s in PLA, P = 0.0143). In obese adolescents, short-term dietary [Formula: see text] supplementation is effective in improving exercise tolerance during severe-intensity exercise. This may prove to be useful in counteracting early fatigue and reduced physical activity in this at-risk population.
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Impact of iron deficiency on exercise capacity and outcome in heart failure with reduced, mid-range and preserved ejection fraction.
Martens, P, Nijst, P, Verbrugge, FH, Smeets, K, Dupont, M, Mullens, W
Acta cardiologica. 2018;(2):115-123
Abstract
BACKGROUND Little information is available about the prevalence and impact on exercise capacity and outcome of iron deficiency in heart failure with mid-range (HFmrEF) and preserved (HFpEF) ejection fraction in comparison to heart failure with reduced ejection-fraction (HFrEF). Furthermore, no data is available about the progression of ID in patients without baseline anaemia. METHODS We evaluated baseline iron and haemoglobin-status in a single-centre, prospective heart failure database. Baseline functional status, VO2max, echocardiography and clinical-outcome (all-cause mortality and heart failure admissions) were evaluated. ID, anaemia, HFrEF, HFmrEF and HFpEF were defined according to established criteria. RESULTS A total of 1197 patients (71% male) were evaluated (HFrEF, n = 897; HFmrEF, n = 229; HFpEF, n = 72). The overall prevalence of ID was 53% (50% in HFrEF; 61% in HFmrEF; 64% in HFpEF) and 36% for anaemia. ID was associated with a lower VO2max in patients with HFrEF, HFmrEF and HFpEF (p < .001 in all). Iron status more closely related to a poor VO2max than anaemia status (p < .001). Furthermore, poor clinical-outcome was more strongly associated with iron status than anaemia status. Exposing eight patients without anaemia to iron deficiency for 39 months resulted in one patient developing new-onset anaemia (defined as progression of ID). Patients with progression of ID exhibited a significant higher risk of heart failure hospitalisation and all-cause mortality (HR = 1.4; CI = 1.01-1.94; p = .046) than patients without progression. CONCLUSIONS Iron deficiency is common in patients with HFrEF, HFmrEF and HFpEF, and negatively affects VO2max and clinical-outcome. Progression of iron deficiency parallels an increased risk for worsening of heart failure.
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The Effect of Nitrate Supplementation on Exercise Tolerance and Performance: A Systematic Review and Meta-Analysis.
Van De Walle, GP, Vukovich, MD
Journal of strength and conditioning research. 2018;(6):1796-1808
Abstract
Van De Walle, GP and Vukovich, MD. The effect of nitrate supplementation on exercise tolerance and performance: a systematic review and meta-analysis. J Strength Cond Res 32(6): 1796-1808, 2018-The purpose of this article was to systematically review the current literature and evaluate the overall efficacy of nitrate supplementation on exercise tolerance and performance by meta-analysis. Studies were eligible for inclusion if they met the following criteria: (a) were an experimental trial published in an English peer-reviewed journal; (b) compared the effects of inorganic nitrate consumption with a non-bioactive supplement control or placebo; (c) used a quantifiable measure of exercise performance; and (d) was carried out in apparently healthy participants without disease. A total of 29 studies were identified that investigated the effects of nitrate supplementation on exercise tolerance or performance in accordance with the criteria outlined. Analysis using time to exhaustion as the outcome variable revealed a significant effect of nitrate supplementation on exercise tolerance (ES = 0.28; 95% confidence interval [CI]: 0.08-0.47; p = 0.006) compared with placebo. Analysis using time to complete a specific distance as the outcome variable revealed no significant effect of nitrate supplementation on exercise performance (ES = -0.05; 95% CI: -0.28 to 0.17; p = 0.64) compared with placebo. Nitrate supplementation is likely to improve exercise tolerance and capacity that may improve exercise performance. More research is required to determine the optimal dose and duration of nitrate supplementation. It would also be important to consider the type of athlete performing the exercise and the duration, intensity, and mode of the exercise performed because these factors are likely to influence the efficacy of nitrate supplementation.
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Effects of taurine on markers of muscle damage, inflammatory response and physical performance in triathletes.
Galan, BS, Carvalho, FG, Santos, PC, Gobbi, RB, Kalva-Filho, CA, Papoti, M, da Silva, AS, Freitas, EC
The Journal of sports medicine and physical fitness. 2018;(9):1318-1324
Abstract
BACKGROUND The practice of prolonged exercise with high intensity, as seen in triathlon training, can cause physiological imbalances that might result in muscle fatigue, muscle damage and changes in systemic inflammatory response, thus reduce the athletes' physical performance, therefore, both adequate total caloric and macronutrient intake also the use of a specific ergogenic aid, as taurine supplementation would be an alternative to prevent inflammation and muscle damage. In order to verify the effects of 8 weeks of taurine and chocolate milk supplementation, markers of muscle damage, inflammation, and aerobic capacity were quantified in triathletes. METHODS A double-blind, crossover, randomized study was conducted with 9 male long-distance triathletes, aged 25-35 years. Supplementation of 3 g of taurine (TAU) or placebo (PLA) associated with 400 mL low fat chocolate milk was performed during an 8-week period. In order to verify the effects of the supplementation protocol markers of muscle damage as lactate dehydrogenase (LDH) and creatine kinase (CK), and inflammatory markers tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were quantified, also triathletes' performance was evaluated by exhaust test on a treadmill. RESULTS It was observed a significant increase in taurine and CK plasma levels after TAU supplementation (P=0.02 and P=0.01, respectively). However, LDH concentrations did not differ significantly after the supplementations performed, and there were no changes in physical performance parameters; anaerobic threshold, perceived exertion, heart rate, and the concentrations of IL-6 and TNF-α. CONCLUSIONS Taurine supplementation did not provide benefits on performance and muscle damage in triathletes.
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Dietary Nitrate Increases VO2peak and Performance but Does Not Alter Ventilation or Efficiency in Patients With Heart Failure With Reduced Ejection Fraction.
Coggan, AR, Broadstreet, SR, Mahmood, K, Mikhalkova, D, Madigan, M, Bole, I, Park, S, Leibowitz, JL, Kadkhodayan, A, Thomas, DP, et al
Journal of cardiac failure. 2018;(2):65-73
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Abstract
BACKGROUND Patients with heart failure with reduced ejection fraction (HFrEF) exhibit lower efficiency, dyspnea, and diminished peak oxygen uptake (VO2peak) during exercise. Dietary nitrate (NO3-), a source of nitric oxide (NO), has improved these measures in some studies of other populations. We determined the effects of acute NO3- ingestion on exercise responses in 8 patients with HFrEF using a randomized, double-blind, placebo-controlled, crossover design. METHODS AND RESULTS Plasma NO3-, nitrite (NO2-), and breath NO were measured at multiple time points and respiratory gas exchange was determined during exercise after ingestion of beetroot juice containing or devoid of 11.2 mmol of NO3-. NO3- intake increased (P < .05-0.001) plasma NO3- and NO2- and breath NO by 1469 ± 245%, 105 ± 34%, and 60 ± 18%, respectively. Efficiency and ventilation during exercise were unchanged. However, NO3- ingestion increased (P < .05) VO2peak by 8 ± 2% (ie, from 21.4 ± 2.1 to 23.0 ± 2.3 mL.min-1.kg-1). Time to fatigue improved (P < .05) by 7 ± 3 % (ie, from 582 ± 84 to 612 ± 81 seconds). CONCLUSIONS Acute dietary NO3- intake increases VO2peak and performance in patients with HFrEF. These data, in conjunction with our recent data demonstrating that dietary NO3- also improves muscle contractile function, suggest that dietary NO3- supplementation may be a valuable means of enhancing exercise capacity in this population.
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Effect of 6 wk of high-intensity one-legged cycling on functional sympatholysis and ATP signaling in patients with heart failure.
Munch, GW, Iepsen, UW, Ryrsø, CK, Rosenmeier, JB, Pedersen, BK, Mortensen, SP
American journal of physiology. Heart and circulatory physiology. 2018;(3):H616-H626
Abstract
Breathlessness during daily activities is the primary symptom in patients with heart failure (HF). Poor correlation between the hemodynamic parameters of left ventricular performance and perceived symptoms suggests that other factors, such as skeletal muscle function, play a role in determining exercise capacity. We investigated the effect of 6 wk of high-intensity, one-legged cycling (HIC; 8 × 4 at 90% one-legged cycling max) on 1) the ability to override sympathetic vasoconstriction (arterial infusion of tyramine) during one-legged knee-extensor exercise (KEE), 2) vascular function (arterial infusion of ACh, sodium nitroprusside, tyramine, and ATP), and 3) exercise capacity in HF patients with reduced ejection fraction ( n = 8) compared with healthy individuals ( n = 6). Arterial tyramine infusion lowered leg blood flow and leg vascular conductance at rest and during KEE before the training intervention in both groups ( P < 0.05) but not during KEE after the training intervention. There was no difference between groups. The peak vasodilatory response to ATP was blunted in HF patients ( P < 0.05), whereas there was no difference in ACh- and sodium nitroprusside-induced vasodilation between HF patients and healthy individuals. ACh-induced vasodilation increased in HF patients after the training intervention ( P < 0.05). HIC improved aerobic capacity in both groups ( P < 0.05), whereas only HF patients made improvements in the 6-min walking distance ( P < 0.05). These results suggest that exercise hyperemia and functional sympatholysis are not altered in HF patients and that functional sympatholysis is improved with HIC in both HF patients and healthy individuals. Moreover, these results suggest that the peak vasodilatory response to ATP is blunted in HF. NEW & NOTEWORTHY The ability to override sympathetic vasoconstrictor activity (by arterial tyramine infusion) during exercise is not different between heart failure patients and healthy individuals and is improved by high-intensity, one-legged cycling training. The peak vasodilatory response to ATP is reduced in heart failure patients.
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Efficacy of patients' preferred exercise modalities in chronic obstructive pulmonary disease: A parallel-group, randomized, clinical trial.
Wu, M, Zhou, LQ, Li, S, Zhao, S, Fan, HJ, Sun, JM, Li, XN, Luo, J, Wang, AQ, Wu, JP, et al
The clinical respiratory journal. 2018;(4):1581-1590
Abstract
INTRODUCTION Physical exercise effectively improves health-related quality of life in patients with chronic obstructive pulmonary disease (COPD). However, application of this medical intervention is problematic, due to poor adherence to the exercise program or unawareness of the significance of this intervention. OBJECTIVE To determine whether COPD patients who adopted personal-preferred exercise modalities (PPEMs) for daily training would demonstrate sustained benefits due to improved adherence. METHODS Stable COPD patients were randomly assigned to the daily PPEMs group or the control group (without extra exercise apart from daily life activities). All other treatments were similar. The primary outcome was the health-related quality of life (HRQoL), measured with St. George's Respiratory Questionnaire (SGRQ) score at 12 months. Other measures included the Borg dyspnea score, 6-min walking distance (6MWD) and lung function variables. RESULTS The intention-to-treat (ITT) population included 94 patients, 68 of them completed the study protocol over 12 months (the PP-population). A greater decline of SGRQ score (improvement of HRQoL) in the PPEMs group than that in the controls was demonstrated over 12 months (-19.1 vs -9.0 in the ITT population and -19.1 vs -8.7 in the PP population, P ≤ .001 for all comparisons), the reduction exceeded the minimal clinically important difference of ≥ 4 points. The PPEMs group also showed a greater reduction than the control group in Borg score at 12 months in the ITT and the PP population as well (P < .01). No significant improvement was found in 6MWD or in lung function variables. CONCLUSIONS COPD patients could benefit from extra daily PPEMs, and the gain may sustain at least for 1 year.
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Acute Capsaicin Supplementation Improves Resistance Training Performance in Trained Men.
Conrado de Freitas, M, Cholewa, JM, Freire, RV, Carmo, BA, Bottan, J, Bratfich, M, Della Bandeira, MP, Gonçalves, DC, Caperuto, EC, Lira, FS, et al
Journal of strength and conditioning research. 2018;(8):2227-2232
Abstract
Conrado de Freitas, M, Cholewa, JM, Freire, RV, Carmo, BA, Bottan, J, Bratfich, M, Della Bandeira, MP, Gonçalves, DC, Caperuto, EC, Lira, FS, and Rossi, FE. Acute capsaicin supplementation improves resistance training performance in trained men. J Strength Cond Res 32(8): 2227-2232, 2018-The purpose of this study was to investigate the acute effect of capsaicin supplementation on performance, rate of perceived exertion (RPE), and blood lactate concentrations during resistance exercise in healthy trained young men. Ten resistance-trained men (age = 22.7 ± 4.0 years, mass = 82.3 ± 9.6 kg, and height = 175 ± 0.1 cm) completed 2 randomized, double-blind trials: capsaicin condition (12 mg) or a placebo condition. Forty-five minutes after supplement consumption, subjects performed 4 sets until movement failure in the squat exercise at 70% of 1 repetition maximum with 90 seconds of rest interval between sets. The total mass lifted (total repetitions × mass lifted) was calculated. The RPE was recorded after the last set. Blood lactate was analyzed after each set of exercise, immediately postexercise, and after 3, 5, and at 30 minutes during recovery. The number of repetitions in each set decreased significantly after all sets compared with set-1 and after set-3 and set-4 in relation to set-2 (p < 0.001); however, total mass lifted was higher in capsaicin compared with placebo (3,919.4 ± 1,227.4 kg vs. 3,179.6 ± 942.4 kg, p = 0.002). Blood lactate increased significantly after each set (p < 0.001); however, there were no differences between conditions. Rate of perceived exertion was significantly less for the capsaicin condition than placebo (17.2 ± 1.0 vs. 18.3 ± 1.7, p = 0.048). In summary, acute capsaicin supplementation improves lower-body resistance training performance in trained young men.
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SYNERGIC TRIAL (SYNchronizing Exercises, Remedies in Gait and Cognition) a multi-Centre randomized controlled double blind trial to improve gait and cognition in mild cognitive impairment.
Montero-Odasso, M, Almeida, QJ, Burhan, AM, Camicioli, R, Doyon, J, Fraser, S, Li, K, Liu-Ambrose, T, Middleton, L, Muir-Hunter, S, et al
BMC geriatrics. 2018;(1):93
Abstract
BACKGROUND Physical exercise, cognitive training, and vitamin D are low cost interventions that have the potential to enhance cognitive function and mobility in older adults, especially in pre-dementia states such as Mild Cognitive Impairment (MCI). Aerobic and progressive resistance exercises have benefits to cognitive performance, though evidence is somewhat inconsistent. We postulate that combined aerobic exercise (AE) and progressive resistance training (RT) (combined exercise) will have a better effect on cognition than a balance and toning control (BAT) intervention in older adults with MCI. We also expect that adding cognitive training and vitamin D supplementation to the combined exercise, as a multimodal intervention, will have synergistic efficacy. METHODS The SYNERGIC trial (SYNchronizing Exercises, Remedies in GaIt and Cognition) is a multi-site, double-blinded, five-arm, controlled trial that assesses the potential synergic effect of combined AE and RT on cognition and mobility, with and without cognitive training and vitamin D supplementation in older adults with MCI. Two-hundred participants with MCI aged 60 to 85 years old will be randomized to one of five arms, four of which include combined exercise plus combinations of dual-task cognitive training (real vs. sham) and vitamin D supplementation (3 × 10,000 IU/wk. vs. placebo) in a quasi-factorial design, and one arm which receives all control interventions. The primary outcome measure is the ADAS-Cog (13 and plus modalities) measured at baseline and at 6 months of follow-up. Secondary outcomes include neuroimaging, neuro-cognitive performance, gait and mobility performance, and serum biomarkers of inflammation (C reactive protein and interleukin 6), neuroplasticity (brain-derived neurotropic factor), endothelial markers (vascular endothelial growth factor 1), and vitamin D serum levels. DISCUSSION The SYNERGIC Trial will establish the efficacy and feasibility of a multimodal intervention to improve cognitive performance and mobility outcomes in MCI. These interventions may contribute to new approaches to stabilize and reverse cognitive-mobility decline in older individuals with MCI. TRIAL REGISTRATION Identifier: NCT02808676. https://www.clinicaltrials.gov/ct2/show/NCT02808676 .
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Association of Serum Zinc Level With Prognosis in Patients With Heart Failure.
Yoshihisa, A, Abe, S, Kiko, T, Kimishima, Y, Sato, Y, Watanabe, S, Kanno, Y, Miyata-Tatsumi, M, Misaka, T, Sato, T, et al
Journal of cardiac failure. 2018;(6):375-383
Abstract
BACKGROUND Zinc is an essential cofactor for energy transfer and physiological heart function, has antioxidant properties, and is involved in multiple signaling pathways. We aimed to investigate the associations between serum zinc levels with prognosis, as well as underlying cardiac function and exercise capacity, in patients with heart failure (HF). METHODS AND RESULTS We measured serum zinc levels in 968 consecutive hospitalized patients with decompensated HF, who were divided into 3 groups based on serum zinc levels (µg/dL): first (zinc ≥75, n = 323), second (62≤ zinc <75, n = 322), and third (zinc <62, n = 323) tertiles. We examined cardiac function and exercise capacity and followed up on all patients. Although cardiac function did not differ among the 3 groups, peak oxygen consumption was significantly lower in the third tertile than in the first and second tertiles (peak oxygen consumption, 14.2 vs 15.9 and 15.2 mL/kg/min, P = .010). In the Kaplan-Meier analysis (mean duration of follow-up 1103 days), cardiac and all-cause mortality was highest in the third tertile compared with the first and second tertiles. In the Cox proportional hazard analysis, serum zinc level was a predictor of cardiac and all-cause mortality. In the subgroup analysis, there were no interactions concerning associations between serum zinc levels with prognosis and other important variables, including age, gender, comorbidities, medications, other micronutrient levels, B-type natriuretic peptide, and left ventricular ejection fraction. The associations between zinc levels with mortality were consistent in all subgroups. CONCLUSION Decreased serum zinc levels are associated with high mortality, accompanied by impaired exercise capacity.