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Effects of hydrogen rich water on prolonged intermittent exercise.
Da Ponte, A, Giovanelli, N, Nigris, D, Lazzer, S
The Journal of sports medicine and physical fitness. 2018;(5):612-621
Abstract
BACKGROUND Recent studies showed a positive effect of hydrogen rich water (HRW) intake on acid-base homeostasis at rest. We investigated 2-weeks of HRW intake on repeated sprint performance and acid-base status during prolonged intermittent cycling exercise. METHODS In a cross over single-blind protocol, 8 trained male cyclists (age [mean±SD] 41±7 years, body mass 72.3±4.4 kg, height 1.77±0.04 m, maximal oxygen uptake [V̇O2max] 52.6±4.4 mL·kg-1·min-1) were provided daily with 2 liters of placebo normal water (PLA, pH 7.6, oxidation/reduction potential [ORP] +230 mV, free hydrogen content 0 ppb) or HRW (pH 9.8, ORP -180 mV, free Hydrogen 450 ppb). Tests were performed at baseline and after each period of 2 weeks of treatment. The treatments were counter-balanced and the sequence randomized. The 30-minute intermittent cycling trial consisted in 10 3-minute blocks, each one composed by 90 seconds at 40% V̇O2max, 60 seconds at 60% V̇O2max, 16 seconds all out sprint, and 14 seconds active recovery. Oxygen uptake (V̇O2), heart rate and power output were measured during the whole test, while mean and peak power output (PPO), time to peak power and Fatigue Index (FI) were determined during all the 16 seconds sprints. Lactate, pH and bicarbonate (HCO3-) concentrations were determined at rest and after each sprint on blood obtained by an antecubital vein indwelling catheter. RESULTS In the PLA group, PPO in absolute values decreased significantly at the 8th and 9th of 10 sprints and in relative values, ΔPPO, decreased significantly at 6th, 8th and 9th of 10 sprints (by mean: -12±5%, P<0.006), while it remained unchanged in HRW group. Mean power, FI, time to peak power and total work showed no differences between groups. In both conditions lactate levels increased while pH and HCO3- decreased progressively as a function of the number of sprints. CONCLUSIONS Two weeks of HRW intake may help to maintain PPO in repetitive sprints to exhaustion over 30 minutes.
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Impact of l-citrulline supplementation on oxygen uptake kinetics during walking.
Ashley, J, Kim, Y, Gonzales, JU
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2018;(6):631-637
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Abstract
Supplementation with l-citrulline (Cit) has been shown to improve muscle oxygenation and oxygen uptake kinetics during moderate- to high-intensity cycling in young men. The aim of this study was to test the hypothesis that Cit would improve oxygen uptake kinetics during walking in older and young adults. In a randomized, double-blind study, 26 (15 women, 11 men) adults between the ages of 20-35 years (n = 15) and 64-86 years (n = 11) completed 7-day periods of taking placebo and Cit (6 g/day) in a crossover manner. Participants walked on a treadmill at 40% heart rate reserve while pulmonary oxygen uptake was measured using indirect calorimetry. Net oxygen cost, mean response time (MRT), and the oxygen deficit were calculated before and after each supplement period. There was no significant change (P > 0.05) in net oxygen cost, MRT, or the oxygen deficit after Cit in older adults, while young adults showed a decrease (P = 0.05) in the oxygen deficit after Cit that tended (P = 0.053) to be different than the change after placebo. Sex-stratified analysis revealed that Cit decreased MRT (P = 0.04, Cohen's d = 0.41) and the oxygen deficit (P < 0.01, Cohen's d = 0.56) in men with the change after Cit being greater than the change after placebo (MRT: -4.5 ± 2.1 vs. 3.4 ± 2.1 s, P = 0.01; deficit: -0.15 ± 0.05 vs. 0.01 ± 0.05 L, P = 0.02). All oxygen uptake parameters were unchanged (P > 0.05) following Cit and placebo in women. Cit does not alter the oxygen cost of moderate-intensity walking in young or older adults, but Cit improved the rate of rise in oxygen uptake at exercise onset in men.
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Effect of 1-week betalain-rich beetroot concentrate supplementation on cycling performance and select physiological parameters.
Mumford, PW, Kephart, WC, Romero, MA, Haun, CT, Mobley, CB, Osburn, SC, Healy, JC, Moore, AN, Pascoe, DD, Ruffin, WC, et al
European journal of applied physiology. 2018;(11):2465-2476
Abstract
PURPOSE Betalains are indole-derived pigments found in beet root, and recent studies suggest that they may exert ergogenic effects. Herein, we examined if supplementation for 7 days with betalain-rich beetroot concentrate (BLN) improved cycling performance or altered hemodynamic and serum analytes prior to, during and following a cycling time trial (TT). METHODS Twenty-eight trained male cyclists (29 ± 10 years, 77.3 ± 13.3 kg, and 3.03 ± 0.62 W/kg) performed a counterbalanced crossover study whereby BLN (100 mg/day) or placebo (PLA) supplementation occurred over 7 days with a 1-week washout between conditions. On the morning of day seven of each supplementation condition, participants consumed one final serving of BLN or PLA and performed a 30-min cycling TT with concurrent assessment of several physiological variables and blood markers. RESULTS BLN supplementation improved average absolute power compared to PLA (231.6 ± 36.2 vs. 225.3 ± 35.8 W, p = 0.050, d = 0.02). Average relative power, distance traveled, blood parameters (e.g., pH, lactate, glucose, NOx) and inflammatory markers (e.g., IL-6, IL-8, IL-10, TNFα) were not significantly different between conditions. BLN supplementation significantly improved exercise efficiency (W/ml/kg/min) in the last 5 min of the TT compared to PLA (p = 0.029, d = 0.45). Brachial artery blood flow in the BLN condition, immediately post-exercise, tended to be greater compared to PLA (p = 0.065, d = 0.32). CONCLUSIONS We report that 7 days of BLN supplementation modestly improves 30-min TT power output, exercise efficiency as well as post-exercise blood flow without increasing plasma NOx levels or altering blood markers of inflammation, oxidative stress, and/or hematopoiesis.
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The Role of Gas Exchange Variables in Cardiopulmonary Exercise Testing for Risk Stratification and Management of Heart Failure with Reduced Ejection Fraction.
Wagner, J, Agostoni, P, Arena, R, Belardinelli, R, Dumitrescu, D, Hager, A, Myers, J, Rauramaa, R, Riley, M, Takken, T, et al
American heart journal. 2018;:116-126
Abstract
Heart failure with reduced ejection fraction (HFrEF) is common in the developed world and results in significant morbidity and mortality. Accurate risk assessment methods and prognostic variables are therefore needed to guide clinical decision making for medical therapy and surgical interventions with the ultimate goal of decreasing risk and improving health outcomes. The purpose of this review is to examine the role of cardiopulmonary exercise testing (CPET) and its most commonly used ventilatory gas exchange variables for the purpose of risk stratification and management of HFrEF. We evaluated five widely studied gas exchange variables from CPET in HFrEF patients based on nine previously used systematic criteria for biomarkers. This paper provides clinicians with a comprehensive and critical overview, class recommendations and evidence levels. Although some CPET variables met more criteria than others, evidence supporting the clinical assessment of variables beyond peak V̇O2 is well-established. A multi-variable approach also including the V̇E-V̇CO2 slope and EOV is therefore recommended.
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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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Protein supplementation enhances cerebral oxygenation during exercise in elite basketball players.
Ho, CF, Jiao, Y, Wei, B, Yang, Z, Wang, HY, Wu, YY, Yang, C, Tseng, KW, Huang, CY, Chen, CY, et al
Nutrition (Burbank, Los Angeles County, Calif.). 2018;:34-37
Abstract
OBJECTIVE The aim of the present study was to examine cerebral oxygenation during high-intensity exercise in elite basketball players who consumed supplements with different whey protein contents after a short postexercise recovery to determine whether changing whey protein content in carbohydrate-based supplementation influences cerebral hemodynamic response when the supplement was consumed during a 2-h recovery after a 1-h exercise challenge. METHODS This was a randomized, counterbalanced crossover study. Fifteen Division 1 collegiate basketball players (18-20 y) consumed 6.25 kcal/kg of either high-protein (36% protein in total calorie) or an isocaloric low-protein (12% protein in total calorie) control supplement in a carbohydrate-based drink immediately after a 1-h cycling (70% of maximal oxygen consumption [VO2max]). After a 2-h rest, the athletes were challenged on a cycloergometer at 80% VO2max. Blood perfusion (total hemoglobin) and oxygen saturation of frontal brain were continuously measured by near-infrared spectroscopy during the cycling. RESULTS Before the cycloergometer test, high-protein supplementation increased peak insulin response and lowered glucose increases during the recovery compared with the low-protein trial. High-protein supplementation enhanced increases in cerebral oxygen saturation (P < 0.01) and attenuated increases in cerebral blood perfusion (total hemoglobin; P < 0.01) during the cycloergometer exercise; and resulted in a 16% longer cycling time (from 474 ± 49 s to 553 ± 78 s, P < 0.05), compared with the low-protein trial. CONCLUSION Enhanced fatigue recovery after consumption of a high-protein supplement is associated with enhanced cerebral oxygenation against exercise challenge, which spares brain blood demand for periphery.
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The effects of two different doses of ultraviolet-A light exposure on nitric oxide metabolites and cardiorespiratory outcomes.
Monaghan, C, McIlvenna, LC, Liddle, L, Burleigh, M, Weller, RB, Fernandez, BO, Feelisch, M, Muggeridge, DJ, Easton, C
European journal of applied physiology. 2018;(5):1043-1052
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Abstract
PURPOSE The present study investigated different doses of ultraviolet-A (UV-A) light on plasma nitric oxide metabolites and cardiorespiratory variables. METHODS Ten healthy male participants completed three experimental conditions, 7 days apart. Participants were exposed to no light (CON); 10 J cm2 (15 min) of UV-A light (UVA10) and 20 J cm2 (30 min) of UV-A light (UVA20) in a randomized order. Plasma nitrite [NO2-] and nitrate [NO3-] concentrations, blood pressure (BP), and heart rate (HR) were recorded before, immediately after exposure and 30 min post-exposure. Whole body oxygen utilization ([Formula: see text]), resting metabolic rate (RMR) and skin temperature were recorded continuously. RESULTS None of the measured parameters changed significantly during CON (all P > 0.05). [Formula: see text] and RMR were significantly reduced immediately after UVA10 (P < 0.05) despite no change in plasma [NO2-] (P > 0.05). Immediately after exposure to UVA20, plasma [NO2-] was higher (P = 0.014) and [Formula: see text] and RMR tended to be lower compared to baseline (P = 0.06). There were no differences in [NO2-] or [Formula: see text] at the 30 min time point in any condition. UV-A exposure did not alter systolic BP, diastolic BP or MAP (all P > 0.05). UV-A light did not alter plasma [NO3-] at any time point (all P > 0.05). CONCLUSIONS This study demonstrates that a UV-A dose of 20 J cm2 is necessary to increase plasma [NO2-] although a smaller dose is capable of reducing [Formula: see text] and RMR at rest. Exposure to UV-A did not significantly reduce BP in this cohort of healthy adults. These data suggest that exposure to sunlight has a meaningful acute impact on metabolic function.
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Effects of cold water immersion on aerobic capacity and muscle strength of young footballers.
Boujezza, H, Sghaier, A, Ben Rejeb, M, Gargouri, I, Latiri, I, Ben Saad, H
La Tunisie medicale. 2018;(2):107-112
Abstract
AIMS: The main aim was to compare aerobic performance data, determined before «period1» and after «period2» cold water immersion in two groups of footballers (CWI and no-CWI groups). METHODS This is an experimental study with matching and randomization. The 20 male footballers, aged 17 to 20 years, were divided into two groups (n = 10 for each) following a random draw. The two groups were age-, height- and weight matched. 1000-m race was made during the two periods. Heart-rate (HR, % of theoretical maximum HR) and hemoglobin oxygen saturation (Oxy-sat, %) were measured before and after the race, and the time of the race (min) was noted. An Oxy-sat decrease > 4 points retained the diagnosis of exercise-induced desaturation. Eight CWI sessions (one per week), until the hip in a standing position (10 min; temperature: 11-12 °C) were performed. RESULTS The two groups were age-, height- and weight matched. Comparatively to the race time of «period1», this of «period2» was decreased in the CWI group (3.21±0.04 vs. 3.15±0.04 min) and was increased in the no-CWI group (3.23±0.05 vs. 3.27±0.07 min). Comparatively to the HRs (before, after the race) of «period1», these of «period2» were decreased in the CWI group (36±1 vs. 34±1%; 56±3 vs. 44±2%) and were increased in the no-CWI group (35±2 vs. 36±1%; 55±2 vs. 57±2%). Comparatively to the after race Oxy-sat' of the «period1», this of «period2» was increased in the CWI group (96±1 vs. 98±0%) and was decreased in the no-CWI group (96±1 vs. 95±1%). While in the CWI group, the percent of desaturators was decreased between «period1» and «period2» (30 vs. 0%), in the no-CWI group, percentages remained similar (50 vs. 90%). CONCLUSION CWI improves aerobic capacity and muscle strength of young footballers.
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Long-term effects of NO3- on the relationship between oxygen uptake and power after three weeks of supplemented HIHVT.
Finkel, A, Röhrich, MA, Maassen, N, Lützow, M, Blau, LS, Hanff, E, Tsikas, D, Maassen, M
Journal of applied physiology (Bethesda, Md. : 1985). 2018;(6):1997-2007
Abstract
The aim of this study was to investigate the later effects of daily NO3- supplementation over 3 wk of training on the relationship between O2 uptake and power at different intensities with an incremental test (IT), a double-wingate test (WT), and an endurance capacity test at 80% Wmax (ECT) before and after the supplementation period. Seventeen male recreational athletes participated in this double-blind placebo (PL)-controlled study. Subjects participated in a 3-wk intermittent high-intensity, high-volume training period with 45 intervals of Wmax - 10 W and an active recovery period of 10 W in between with dietary NO3- (NaNO3) or placebo supplementation (NaCl) (both 8.5 mg·kg-1·day-1) on a cycle ergometer. During a training session, plasma [ NO3- ] ( P < 0.001) and plasma [ NO2- ] ( P < 0.01) were higher in nitrate (N), whereas in pre- and posttests mean plasma [ NO3- ] and [ NO2- ] were not different between groups. In the WT [48 h after cessation of supplementation (C)], the ratio between V̇o2 and power decreased in N ( P < 0.01) with no changes in PL. Endurance capacity (4-5 days after C) similarly increased in both groups ( P < 0.01). However, the total oxygen consumption decreased by 5% ( P < 0.01) in N, with no change in PL. The slope of V̇o2·W-1 in IT (5-7 days after C) decreased in N ( P < 0.01), whereas no changes were found in PL. During low- and moderate-intensity workloads, no changes and differences in V̇o2 could be detected. We conclude that nitrate supplementation causes a sustaining reduction of the oxygen cost per watt during exercise with a large recruitment of type II muscle fibers without affecting endurance capacity. NEW & NOTEWORTHY Because most studies focused on the acute effects of NO3- supplementation on exercise performance during a supplementation period, the sustainability of the effects of the NO3- supplementation remain unknown. We followed the development of V̇o2/W at different intensities during the first week after cessation of daily NO3- supplementation over 3 wk. The results indicate that NO3- supplementation has a long-term effect for at least 7 days after cessation during heavy all-out workloads without affecting endurance capacity.
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Effects of a Short-Term Recreational Team Handball-Based Programme on Physical Fitness and Cardiovascular and Metabolic Health of 33-55-Year-Old Men: A Pilot Study.
Póvoas, SCA, Castagna, C, Resende, C, Coelho, EF, Silva, P, Santos, R, Pereira, R, Krustrup, P
BioMed research international. 2018;:4109796
Abstract
Recreational team handball is an intermittent high-intensity exercise mode with physiological demands in the range of those found to enhance health and physical fitness of sedentary adults. We examined the effects of a short-term team handball-based training programme on physical fitness and metabolic and cardiovascular health of sedentary 33-55-year-old former male team handball players. Twenty-four participants were divided into team handball (THG; n=15) and control groups (CG; n=9) and evaluated at baseline and postintervention. During 12 weeks, THG performed 2-3 60-min recreational team handball matches weekly (average: 2.2 ± 0.7), and CG maintained an inactive lifestyle. Average heart rate (HR) during matches was 80 ± 7%HRmax, with peak values of 91 ± 6%HRmax. A time-by-group interaction was shown in aerobic performance (p=0.016), postural balance (p=0.019), maximum oxygen uptake (VO2max) (p=0.023), resting HR (p<0.001), high-density lipoprotein (HDL) cholesterol (p=0.048), and fasting blood glucose (p=0.052) in favor of THG. THG improved aerobic performance (80%, p<0.001), VO2max (14%, p<0.001), and postural balance (27%, p=0.018). Decreases in resting HR (16%, p<0.001) and fasting blood glucose (7%, p=0.015) and increases in HDL cholesterol (11%, p=0.002) were found in THG. Recreational team handball practice shows positive physical fitness and health-related adaptations, with high attendance, which may contribute to the reduction of the risk of developing lifestyle diseases.