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1.
Blueberry supplementation reduces the blood lactate response to running in normobaric hypoxia but has no effect on performance in recreational runners.
Brandenburg, JP, Giles, LV
Journal of the International Society of Sports Nutrition. 2021;(1):26
Abstract
BACKGROUND Blueberries are concentrated with anthocyanins possessing antioxidant properties. As these properties counter fatigue, blueberry supplementation may improve performance and recovery, particularly in hypoxia, where oxidative stress is elevated. METHODS This study examined the effects of blueberry supplementation on running performance, physiological responses, and recovery in normobaric hypoxia. Eleven experienced runners completed a 30-minute time-trial (TT) in normobaric hypoxia (%O2 = 15.5 %) on separate days after supplementation with four days of blueberries (BLU) or four days of placebo (PLA). Heart rate (HR), oxygen saturation (SaO2) and ratings of perceived exertion (RPE) were monitored during the TT. Blood lactate and fraction of exhaled nitric oxide (FENO) were assessed pre-TT, post-TT, and during recovery. RESULTS No significant differences were observed in the distance run during the TT, HR, SaO2, and RPE. The post-TT increase in blood lactate was significantly lower in BLU than PLA (p = 0.036). Pre-TT and post-TT FENO did not differ between conditions. Blood lactate recovery following the TT was similar between conditions. CONCLUSIONS Four days of blueberry supplementation did not alter running performance or cardiovascular and perceptual responses in normobaric hypoxia. Supplementation lowered the blood lactate response to running, however, the significance of this finding is uncertain given the absence of an ergogenic effect.
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2.
Training response to 8 weeks of blood flow restricted training is not improved by preferentially altering tissue hypoxia or lactate accumulation when training to repetition failure.
Morley, WN, Ferth, S, Debenham, MIB, Boston, M, Power, GA, Burr, JF
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2021;(10):1257-1264
Abstract
Despite compelling muscular structure and function changes resulting from blood flow restricted (BFR) resistance training, mechanisms of action remain poorly characterized. Alterations in tissue O2 saturation (TSI%) and metabolites are potential drivers of observed changes, but their relationships with degree of occlusion pressure are unclear. We examined local TSI% and blood lactate (BL) concentration during BFR training to failure using different occlusion pressures on strength, hypertrophy, and muscular endurance over an 8-week training period. Twenty participants (11 males/9 females) trained 3/wk for 8 wk using high pressure (100% resting limb occlusion pressure, LOP; 20% one-repetition maximum (1RM)), moderate pressure (50% LOP, 20%1RM), or traditional resistance training (TRT; 70%1RM). Strength, size, and muscular endurance were measured pre/post training. TSI% and BL were quantified during a training session. Despite overall increases, no group preferentially increased strength, hypertrophy, or muscular endurance (p > 0.05). Neither TSI% nor BL concentration differed between groups (p > 0.05). Moderate pressure resulted in greater accumulated deoxygenation stress (TSI% × time) (-6352 ± 3081, -3939 ± 1835, -2532 ± 1349 au for moderate pressure, high pressure, and TRT, p = 0.018). We demonstrate that BFR training to task-failure elicits similar strength, hypertrophy, and muscular endurance changes to TRT. Further, varied occlusion pressure does not impact these outcomes or elicit changes in TSI% or BL concentrations. Novelty: Training to task failure with low-load blood flow restriction elicits similar improvements to traditional resistance training, regardless of occlusion pressure. During blood flow restriction, altering occlusion pressure does not proportionally impact tissue O2 saturation nor blood lactate concentrations.
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3.
Effects of mechanical bed massage on biochemical markers of exercise-induced back muscle fatigue in athletes: A randomized controlled trial.
Zhong, H, Eungpinichpong, W, Wang, X, Chatchawan, U, Wanpen, S, Buranruk, O, Wang, C
Journal of back and musculoskeletal rehabilitation. 2020;(5):793-800
Abstract
BACKGROUND Many previous studies have explored the effects of manual massage on back muscle fatigue, and most of the mechanical massage techniques imitate manual massage. However, it is unknown whether mechanical and manual massage have the same functions for exercise-induced back muscle fatigue. OBJECTIVE To investigate the effects of mechanical bed massage on the biochemical markers of exercise-induced back muscle fatigue in male collegiate athletes. METHODS Twenty-eight male collegiate athletes who met the experimental criteria were recruited in this randomized controlled trial, and randomly assigned to a mechanical bed massage group (experimental group) or resting group (control group). The subjects performed eight bouts of reverse sit-up in the prone position and received 20 minutes of the intervention. Creatine kinase, blood lactate, and serum cortisol levels were measured at baseline, after fatigue, after intervention, and after 24 hours. RESULTS The level of serum cortisol of the control group was significantly higher than that of the experimental group after the intervention (p< 0.05). The comparison of the two groups for blood lactate levels showed no significant differences at any of the measurement time-points (p> 0.05). There was no significant difference in creatine kinase levels immediately after the intervention (p> 0.05), but a significant difference in creatine kinase level was observed between the two groups 24 hours later (p< 0.05). CONCLUSIONS Significant differences were observed between mechanical bed massage and rest condition on serum cortisol and creatine kinase for exercise-induced muscle fatigue. Therefore, mechanical bed massage may reduce stress and muscle damage for the athlete after training or competition.
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4.
Beta alanine supplementation effects on metabolic contribution and swimming performance.
Norberto, MS, Barbieri, RA, Bertucci, DR, Gobbi, RB, Campos, EZ, Zagatto, AM, De Freitas, EC, Papoti, M
Journal of the International Society of Sports Nutrition. 2020;(1):40
Abstract
BACKGROUND Investigations of β-alanine supplementation shows effects on metabolic (aerobic and anaerobic) participation and performance on swimming by a possible blood acidosis buffering. Considering this background, the objective of the present study was to analyze the effects of β-alanine supplementation on metabolic contribution and performance during 400-m swim. METHODS Thirteen competitive swimmers underwent a 6-week, double-blind placebo-controlled study, ingesting 4.8 g.day- 1 of β-alanine or placebo. Before and after the supplementation period, the total anaerobic contribution (TAn) and 30-s all-out tethered swimming effort (30TS) were assessed. Anaerobic alactic (AnAl) and lactic energy (AnLa) was assumed as the fast component of excess post-exercise oxygen consumption and net blood lactate accumulation during exercise (∆[La-]), respectively. Aerobic contribution (Aer) was determined by the difference between total energy demand and TAn. In addition to conventional statistical analysis (Repeated measures ANOVA; p > 0.05), a Bayesian repeated measures ANOVA was used to evidence the effect probability (BFincl). RESULTS No differences and effects were found between groups, indicating no supplementation effects. Repeated measures ANOVA, with confirmation of effect, was indicate reduce in ∆Lactate (p: 0.001; BFincl: 25.02); absolute AnLa (p: 0.002; BFincl: 12.61), fatigue index (p > 0.001; BFincl: 63.25) and total anaerobic participation (p: 0.008; BFincl: 4.89). CONCLUSIONS Thus, the results demonstrated that all changes presented were evidenced as a result of exposure to the training period and β-alanine supplementation doesn't affect metabolic contribution and performance during 400-m freestyle.
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5.
Long-term docosahexaenoic acid (DHA) supplementation in cystic fibrosis patients: a randomized, multi-center, double-blind, placebo-controlled trial.
López-Neyra, A, Suárez, L, Muñoz, M, de Blas, A, Ruiz de Valbuena, M, Garriga, M, Calvo, J, Ribes, C, Girón Moreno, R, Máiz, L, et al
Prostaglandins, leukotrienes, and essential fatty acids. 2020;:102186
Abstract
BACKGROUND Cystic fibrosis (CF) patients have an alteration in fatty acid (FA) metabolism, associated with increased omega-6 and low omega-3 FA. Previous studies on supplementation with omega-3 FA in CF had contradictory results, and to date there is no evidence to recommend routine use of omega-3 supplements in CF patients. We hypothesized that long-term supplementation with docosahexaenoic acid (DHA) will have beneficial effects in these patients, by reducing pulmonary, systemic and intestinal inflammation. METHODS This was a randomized, double-blind, parallel, placebo-controlled trial. CF patients (age >2 months) were randomized to receive a seaweed DHA oil solution (50 mg/Kg/day) or matching placebo for 48 weeks. Primary outcomes were pulmonary (interleukin [IL]-8), systemic (IL-8) and intestinal (calprotectin) inflammatory biomarkers. Secondary outcomes included other pulmonary (IL-1β, IL-6, neutrophil elastase, lactate and calprotectin) and systemic (serum-IL-1β, IL-6) inflammatory biomarkers, as well as clinical outcomes (FEV1, pulmonary exacerbations, antibiotic use, nutritional status and quality of life). RESULTS Ninety six CF patients, 44 female, age 14.6±11.9 years (48 DHA and 48 placebo) were included. At trial completion, there were no differences in all primary outcomes [serum-IL-8 (p=0.909), respiratory-IL-8 (p=0.384) or fecal calprotectin (p=0.948)], all secondary inflammatory biomarkers, or in any of the clinical outcomes evaluated. There were few adverse events, with similar incidence in both study groups. CONCLUSION In this study, long-term DHA supplementation in CF patients was safe, but did not offer any benefit on inflammatory biomarkers, or in clinical outcomes compared with placebo. (NCT01783613).
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6.
Effect of magnesium supplementation on lactate clearance in critically ill patients with severe sepsis: a randomized clinical trial.
Noormandi, A, Khalili, H, Mohammadi, M, Abdollahi, A
European journal of clinical pharmacology. 2020;(2):175-184
Abstract
OBJECTIVES In this study, changes in lactate clearance following magnesium supplementation were evaluated in critically ill patients with severe sepsis. METHODS Fifty-eight patients with severe sepsis were randomly assigned to receive either magnesium (n = 30) or placebo (n = 28). Patients in the magnesium group received intravenous magnesium sulfate to maintain serum magnesium level around 3 mg/dL for 3 days. The placebo group received the same volume of normal saline. Change in lactate clearance was considered primary outcome of the study. RESULTS Mean increase in the lactate clearance in the magnesium group was significantly higher than the placebo group on day 2 (27.53% vs. 23.79% respectively, p < 0.001) and day 3 (49.83% vs. 37.02% respectively, p < 0.001). Time to lactate clearance was also significantly shorter in the magnesium group than the placebo group (47.28 ± 20.59 vs. 61.20 ± 24.31 h respectively, p = 0.03). Sepsis-related mortality was not significantly different but median length of ICU stay was significantly shorter in the magnesium group than the placebo group (8 vs. 15 days respectively, p < 0.01). CONCLUSIONS Magnesium supplementation increased lactate clearance in critically ill patients with severe sepsis. Optimizing serum magnesium level near the upper limit of the normal range may improve severe sepsis outcomes.
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7.
High doses of sodium bicarbonate increase lactate levels and delay exhaustion in a cycling performance test.
Ferreira, LHB, Smolarek, AC, Chilibeck, PD, Barros, MP, McAnulty, SR, Schoenfeld, BJ, Zandona, BA, Souza-Junior, TP
Nutrition (Burbank, Los Angeles County, Calif.). 2019;:94-99
Abstract
OBJECTIVES It is well established that ingestion of sodium bicarbonate (NaHCO3) causes metabolic alkalosis. However, there is no consensus in terms of optimal NaHCO3 doses leading to enhanced performance. This study aimed to determine the effects of different NaHCO3 doses on performance and lactate clearance in non-professional cyclists. METHODS Twenty-one cyclists performed the following three double-blind trials: 1) ingestion of 0.3 g · kg-1 body weight (BW) of placebo; 2) ingestion of 0.1 g · kg-1 BW NaHCO3 plus 0.2 g · kg-1 BW placebo (0.1 BC); and 3) ingestion of 0.3 g · kg-1 BW NaHCO3 (0.3 BC). Performance was evaluated after warm-up on the bike followed by a performance test until exhaustion. Lactate levels were monitored in blood samples before and immediately after performance tests. RESULTS Lactate levels in the blood were significantly higher after exercise in 0.3 BC and 0.1 BC (15.12 ± 0.92 versus 10.3 ± 1.22 and 13.24 ± 0.87 versus 10.3 ± 1.22 mmol/L; P < 0.05) compared with control. Significant improvements in performance were only identified in 0.3 BC group (76.42 ± 2.14; P = 0.01). CONCLUSIONS The present study found that 0.3 g · kg-1 BW NaHCO3 is effective in improving performance and improving blood lactate levels in cyclists compared with control and 0.1 g · kg-1 BW NaHCO3.
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8.
Four Days of Blueberry Powder Supplementation Lowers the Blood Lactate Response to Running But Has No Effect on Time-Trial Performance.
Brandenburg, JP, Giles, LV
International journal of sport nutrition and exercise metabolism. 2019;(6):636-642
Abstract
Blueberries are abundant with anthocyanins possessing antioxidant and anti-inflammatory properties. As these properties combat fatigue and promote recovery, blueberry supplementation may enhance performance and recovery. Thus, the objectives were to examine the effects of two blueberry supplementation protocols on running performance, physiological responses, and short-term recovery. Using a randomized, double-blind, placebo (PLA)-controlled crossover design, 14 runners completed an 8-km time trial (TT) after supplementation with 4 days of blueberries (4DAY), 4 days of a PLA, or 2 days of placebo followed by 2 days of blueberries (2DAY). Heart rate and ratings of perceived exertion were monitored during the TT. Blood lactate, vertical jump, reactive strength index, and salivary markers were assessed before and after. No significant differences were observed for time to complete the TT (PLA: 3,010 ± 459 s; 2DAY: 3,014 ± 488 s; 4DAY: 3,011 ± 423 s), heart rate, ratings of perceived exertion, or any of the salivary markers. An interaction effect (p = .027) was observed for blood lactate, with lower post-TT concentrations in 4DAY (5.4 ± 2.0 mmol/L) than PLA (6.6 ± 2.5 mmol/L; p = .038) and 2DAY (7.4 ± 3.4 mmol/L; p = .034). Post-TT decreases in vertical jump height were not different, whereas the decline in reactive strength index was less following 4DAY (-6.1% ± 13.5%) than the other conditions (PLA: -12.6% ± 10.1%; 2DAY: -11.6% ± 11.5%; p = .038). Two days of supplementation did not influence performance or physiological stress. Although 4 days of supplementation did not alter performance, it blunted the increase in blood lactate, perhaps reflecting altered lactate production and/or clearance, and offset the decrease in dynamic muscle function post-TT, as indicated by the reactive strength index differences.
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9.
Hydrogen Rich Water Improved Ventilatory, Perceptual and Lactate Responses to Exercise.
Botek, M, Krejčí, J, McKune, AJ, Sládečková, B, Naumovski, N
International journal of sports medicine. 2019;(14):879-885
Abstract
The potential anti-fatigue and performance benefits of hydrogen rich water (HRW) have resulted in increased research interest over the past 5 years. The aim of this study was to assess physiological and perceptual responses to an incremental exercise protocol after administration of 600 ml HRW within 30 min before exercise. This randomized, double blinded placebo-controlled cross over study included twelve healthy males aged 27.1±4.9 years. The exercise protocol consisted of a 10 min warm-up at 1.0 W.kg-1, followed by 8 min at 2.0, 3.0, and 4.0 W.kg-1, respectively. Cardio-respiratory variables, lactate and ratings of perceived exertion (RPE) were assessed in the last minute of each step. A significantly lower blood lactate was found with HRW (4.0±1.6 and 8.9±2.2 mmol.l-1) compared to Placebo (5.1±1.9 and 10.6±3.0 mmol.l-1) at 3.0, and 4.0 W.kg-1, respectively. Ventilatory equivalent for oxygen and RPE exhibited significantly lower values with HRW (32.3±7.2, and 17.8±1.2 points, respectively) compared to Placebo (35.0±8.4, and 18.5±0.8 points, respectively) at 4 W.kg-1. To conclude, acute pre-exercise supplementation with HRW reduced blood lactate at higher exercise intensities, improved exercise-induced perception of effort, and ventilatory efficiency.
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10.
The effect of cold ambient temperature and preceding active warm-up on lactate kinetics in female cyclists and triathletes.
Morrissey, MC, Kisiolek, JN, Ragland, TJ, Willingham, BD, Hunt, RL, Hickner, RC, Ormsbee, MJ
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2019;(10):1043-1051
Abstract
The aim of this study was to evaluate the effect of cold ambient temperature on lactate kinetics with and without a preceding warm-up in female cyclists/triathletes. Seven female cyclists/triathletes participated in this study. The randomized, crossover study included 3 experimental visits that comprised the following conditions: (i) thermoneutral temperature (20 °C; NEU); (ii) cold temperature (0 °C) with no active warm-up (CNWU); and (iii) cold temperature (0 °C) with 25-min active warm-up (CWU). During each condition, participants performed a lactate threshold (LT) test followed by a time to exhaustion trial at 120% of the participant's peak power output (PPO) as determined during prior peak oxygen consumption testing. Power output at LT with CNWU was 10.2% ± 2.6% greater than with NEU, and the effect was considered very likely small (effect size (ES) = 0.59, 95%-99% likelihood). Power output at LT with CNWU was 4.2% ± 5.4% greater than with CWU; however, the effect was likely trivial (ES = 0.25, 75%-95% likelihood). At LT, there were no significant differences between interventions groups in oxygen consumption, blood lactate concentration, heart rate, or rating of perceived exertion. Time to exhaustion at 120% at PPO was 11% longer with CNWU than with CWU (ES = 0.62, respectively), and this effect was likely small. These findings suggest that power output at LT was higher in CNWU compared with NEU. Additionally, time to exhaustion at 120% of PPO was higher in CNWU compared with CWU and no different than NEU; these differences likely result in a small improvement in performance with CNWU versus CWU and NEU.