The effects of taurine ingestion on anaerobic and physiological performance in female rugby players

The purpose of this study was to investigate the acute effect of low, moderate, or high doses of taurine on anaerobic and physiological performance in female rugby players. A total of 16 sub-elite female rugby athletes (21.3 ± 1.5 yr, 168.0 ± 4.9 cm, 62.1 ± 3.5 kg mean ± SD) participated in this research. Following familiarization, participants attended 4 successive tests separated by 72 h in a randomized, counter-balanced, crossover research design. Following an over night fast, participants completed a 5-min 60 Watt warm-up followed by a 30-s Wingate anaerobic test on a cycle ergometer after ingestion of either 2 g taurine (LOWTAU), 4 g (MODTAU), 6 g (HIGHTAU) or placebo (PLA) 1 h before the test. Peak (PP) and mean power (MP) along with heart rate (HR), rating of perceived exertion (RPE), capillary lactate and blood glucose were measured. LOWTAU did not affect PP, MP, HR, lactate and glucose compared to PLA (p > 0.05), while MODTAU improved MP and HIGHTAU improved PP and MP compared to PLA and LOWTAU (p < 0.05). MODTAU and HIGHTAU had little effect on HR, blood lactate and glucose (p > 0.05). A single dose of taurine (MODTAU or HIGHTAU) 1 h prior to competition or training would provide an ergogenic effect on subsequent power output.

Validation of the AC[La]+EPOCfast Method in Sprinters and Middle-distance Runners

The anaerobic capacity (AC[La]+EPOCfast) method is of interest as it can differentiate between the contributions of phosphocreatine (PCr) and glycolytic energy, assess the anaerobic metabolism during a single effort, and evaluate various exercise modalities. However, no previous studies have investigated whether the superiority of the PCr and glycolytic systems can be assessed in athletes with high anaerobic capacity. This study aimed to compare the AC[La]+EPOCfast method in seven sprinters (SP) and seven middle-distance runners (MD). The participants underwent a graded exercise test and constant-load exercise at 115% ˙VO2max until exhaustion using a bicycle ergometer. AC[La]+EPOCfast was calculated as the sum of oxygen equivalents from the phosphagen (EPCr) and glycolytic (ELa) pathways. This study reveals that there was no significant difference in AC[La]+EPOCfast or maximal accumulated oxygen deficit (MAOD) between the two groups. Although EPCr was not significantly different between groups, ELa was significantly higher in the SP group than in the MD group. In conclusion, the AC[La]+EPOCfast method can be used to evaluate high and low anaerobic capacities. However, further studies on athletes with high aerobic capacity are required.

Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration

Purpose: Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by the exercise (in mM) by 3.3 (or 3) mL·kg-1 per mM. Our purpose was to verify the value of this conversion factor, using methods that were completely different from those of the original studies. Methods: Six women (mean ± SD), age, 23 ± 1 year; VO2max, 46 ± 4 mL·kg-1·min-1) and three men (23 ± 0 years; 54 ± 8 mL·kg-1·min-1) completed 6 min of heavy intensity exercise in conditions of normoxia and hypoxia (FIO2, ∼12%). VO2 was measured throughout the exercise and 7 min of recovery. The increase in glycolytic contribution was estimated as the reduction in aerobic contribution in hypoxia, after correction for the effects of hypoxia on the oxygen demand and on the contribution from phosphocreatine. The peak post-exercise blood lactate concentration was measured in fingerstick blood samples. Results: The ratio between the increase in estimated glycolytic contribution (in mL·kg-1) in hypoxia and the increase in peak blood lactate concentration (in mM) yielded an oxygen equivalent of 3.4 ± 0.4 mL·kg-1 per mM (range, 2.6 mL·kg-1 per mM to 4.0 mL·kg-1 per mM) for cycle ergometer exercise. Conclusion: These results generally support the use of a common conversion factor to calculate the glycolytic contribution from post-exercise blood lactate concentrations. However, there is some inter-individual variability in the conversion factor.

Does Single or Combined Caffeine and Taurine Supplementation Improve Athletic and Cognitive Performance without Affecting Fatigue Level in Elite Boxers? A Double-Blind, Placebo-Controlled Study

In previous studies, the effect of single or combined intake of caffeine (CAF) and taurine (TAU) on exercise performance was investigated. However, the potential synergistic effect on physical and cognitive performance after fatigue induced by anaerobic exercise is unknown. The effects of single and combination CAF and TAU supplementation on the Wingate test in elite male boxers and to evaluate balance, agility and cognitive performance after fatigue are being investigated for the first time in this study. Twenty elite male boxers 22.14 ± 1.42 years old were divided into four groups in this double-blind, randomized crossover study: CAF (6 mg/kg of caffeine), TAU (3 g single dose of taurine), CAF*TAU (co-ingestion of 3 g single dose of taurine and 6 mg/kg of caffeine) and PLA (300 mg maltodextrin). The findings are as follows: co-ingestion of CAF*TAU, improved peak (W/kg), average (W), minimum (W) power, time to reach (s), and RPE performances compared to the PLA group significantly (p < 0.05). Similarly, it was determined that a single dose of TAU, created a significant difference (p < 0.05) in peak power (W/kg), and average and minimum power (W) values compared to the CAF group. According to the balance and agility tests performed after the Wingate test, co-ingestion of CAF*TAU revealed a significant difference (p < 0.05) compared to the PLA group. In terms of cognitive performance, co-ingestion of CAF*TAU significantly improved the neutral reaction time (ms) compared to the TAU, CAF and PLA groups. As a result, elite male boxers performed better in terms of agility, balance and cognitive function when they consumed a combination of 6 mg/kg CAF and 3 g TAU. It has been determined that the combined use of these supplements is more effective than their single use.

Anaerobic Contribution Determined in Free-Swimming: Sensitivity to Maturation Stages and Validity

Evaluation of anaerobic contribution is important under swimming settings (training and modification through ages), therefore, it is expected to change during maturation. The accumulated oxygen deficit (AOD) method can be used to determine the contribution of nonoxidative energy during swimming; however, it requires several days of evaluation. An alternative method to estimate anaerobic contribution evaluation (AC_ALT), which can also be evaluated without snorkel (i.e., free-swimming, AC_FS), has been proposed; however, these methods have never been compared. Thus, this study (i) analyzed the effect of maturation stage on AC_FS during maximal 400 m swimming (Part I), and (ii) compared AOD with AC_ALT and AC_FS, determined in a maximal 400 m effort (Part II). In Part I, 34 swimmers were divided into three groups, according to maturation stages (early-pubertal, middle-pubertal, and pubertal), and subjected to a maximal 400 m free-swimming to determine AC_FS. In Part II, six swimmers were subjected to one 400 m maximal effort, and four submaximal constant efforts. The AOD was determined by the difference between the estimated demand and accumulated oxygen during the entire effort. The AC_ALT and AC_FS (for Part I as well) was assumed as the sum of lactic and alactic anaerobic contributions. AC_FS was higher in pubertal (3.8 ± 1.1 L) than early (2.1 ± 0.9 L) and middle pubertal group (2.4 ± 1.1 L). No difference was observed among absolute AOD (3.2 ± 1.3 L), AC_ALT (3.2 ± 1.5 L), and AC_FS (4.0 ± 0.9 L) (F = 3.6; p = 0.06). Relative AOD (51.8 ± 12.2 mL·kg⁻¹), AC_ALT (50.5 ± 14.3 mL·kg⁻¹), and AC_FS (65.2 ± 8.8 mL·kg⁻¹) presented main effect (F = 4.49; p = 0.04), without posthoc difference. The bias of AOD vs. AC_ALT was 0.04 L, and AOD vs. AC_FS was −0.74 L. The limits of agreement between AOD and AC_ALT were +0.9 L and −0.8 L, and between AOD and AC_FS were +0.7 L and −2.7 L. It can be concluded that AC_FS determination is a feasible tool to determine anaerobic contribution in young swimmers, and it changes during maturation stages. Also, AC_FS might be useful to measure anaerobic contribution in swimmers, especially because it allows greater speeds.

Effects of Multi-Ingredient Pre-Workout Supplement and Caffeine on Bench Press Performance: A Single-Blind Cross-Over Study

The problem addressed in this study is the appropriateness of using different pre-training supplementation strategies and their ability to improve training performance and psychological measures. The aim of the study is the evaluation of the effectiveness of a multi-ingredient pre-workout supplement (MIPS) containing beta-alanine, L-citrulline malate, arginine alpha-ketoglutarate, L-taurine, L-tyrosine and caffeine compared to an exact dosage of anhydrous caffeine in bench press strength endurance, feeling scale (FS), felt arousal scale (FAS) and session rating of perceived exertion (sRPE). A group of fifteen resistance-trained males, weighing 83.92 ± 8.95 kg and having an average of 5.6 ± 3.38 years of training experience, tested their bench press 10 repetition maximum (79.01 ± 12.13). In a cross-over manner, they participated in two sessions where they were blinded to the order of supplementation they were given: either a MIPS including caffeine or caffeine alone. They completed the bench press strength endurance test with pre- and post-training psychological assessments containing FS, FAS and sRPE. Bench press repetition volume was greater after anhydrous caffeine than MIPS supplementation with no difference in psychological measures. These results indicate that MIPS supplementation is less ergogenic and cost effective than caffeine alone.

Recent insights into the molecular regulators and mechanisms of taurine to modulate lipid metabolism: a review

Lipid metabolism disorders such as hypertriglyceridemia and hypercholesterolemia are risk factors for cardiovascular diseases and atherosclerosis that are grave public health issues. Taurine, a sulfur-containing non-essential amino acid exerts a wide range of physiological effects that regulate lipid metabolic disorders. Although the effects of taurine on lipid-lowering have been reported in animals and humans, mechanisms elucidating the lipid-lowering action of taurine remain unclear. A series of molecular regulators associated with lipid metabolism have been identified in the past few decades. These include nuclear receptors, transcription factors, and enzymes that undergo important changes during taurine treatment. In this review, we focus on the role of taurine in lipid metabolism and discuss taurine-related interventions in combating lipid disorders.

Combined but Not Isolated Ingestion of Caffeine and Taurine Improves Wingate Sprint Performance in Female Team-Sport Athletes Habituated to Caffeine

Previous studies have investigated caffeine (CAF) and taurine (TAU) in isolation and combined during exercise in males. However, the potential synergistic effect during high-intensity exercise remains unknown in female athletes. Seventeen female team-sport athletes participated (age: 23.4 ± 2.1 years; height: 1.68 ± 0.05 m; body mass: 59.5 ± 2.2 kg). All participants were habitual caffeine consumers (340.1 ± 28.6 mg/day). A double-blind randomized crossover design was used. Participants completed four experimental trials: (i) CAF and TAU (6 mg/kg body mass of CAF + 1 g of TAU), (ii) CAF alone; (iii) TAU alone; and (iv) placebo (PLA). Supplements were ingested 60 min before a 30-s Wingate Anaerobic Test (WAnT). Heart rate and blood lactate (BL) were measured before and immediately after the WAnT; and ratings of perceived exertion (RPE) were recorded immediately after the WAnT. Peak power (PP) was significantly higher following co-ingestion of CAF+TAU compared to PLA (p = 0.03) and TAU (p = 0.03). Mean power (MP) was significantly higher following co-ingestion of CAF+TAU compared to PLA (p = 0.01). No other differences were found between conditions for PP and MP (p > 0.05). There were also no observed differences in fatigue index (FI), BL; heart rate; and RPE between conditions (p > 0.05). In conclusion, compared to PLA the combined ingestion of 6 mg/kg of CAF and 1 g of TAU improved both PP and MP in female athletes habituated to caffeine; however; CAF and TAU independently failed to augment WAnT performance.

The Dose Response of Taurine on Aerobic and Strength Exercises: A Systematic Review

Taurine is a naturally occurring amino acid involved in various functions, including regulating ion channels, cell volume, and membrane stabilization. However, how this molecule orchestrates such functions is unknown, particularly the dose response in exercised muscles. Therefore, this review aimed to systematically review the dose response of taurine on both aerobic and strength exercise performance. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, relevant articles were sought on PubMed, Medline, Web of Science, and Google Scholar using related terms, including taurine, exercise performance, exercise, muscle, physical training, running, strength, endurance exercise, resistance exercise, aerobic exercise, and swimming. Ten articles were retrieved, reviewed, and subjected to systematic analysis. The following parameters were used to assess exercise performance in the selected studies: creatine kinase (CK), lactic acid dehydrogenase, carbohydrate, fat, glycerol, malondialdehyde, enzymatic antioxidants, blood pH, taurine level, and muscular strength. From the selected literature, we observed that taurine supplementation (2 g three times daily) with exercise can decrease DNA damage. Furthermore, 1 g of acute taurine administration before or after exercise can decrease lactate levels. However, acute administration of taurine (6 g) at a high dose before the start of exercise had no effect on reducing lactate level, but increased glycerol levels, suggesting that taurine could be an effective agent for prolonged activities, particularly at higher intensities. However, further studies are warranted to establish the role of taurine in fat metabolism during exercise. Finally, we observed that a low dose of taurine (0.05 g) before performing strength enhancing exercises can decrease muscular fatigue and increase enzymatic antioxidants.

Systematic Review Registration:http://www.crd.york.ac.uk/PROSPERO, PROSPERO (CRD42021225243).

Taurine in sports and exercise

BACKGROUND

Taurine has become a popular supplement among athletes attempting to improve performance. While the effectiveness of taurine as an ergogenic aid remains controversial, this paper summarizes the current evidence regarding the efficacy of taurine in aerobic and anaerobic performance, metabolic stress, muscle soreness, and recovery.

METHODS

Google Scholar, Web of Science, and MedLine (PubMed) searches were conducted through September 2020. Peer-reviewed studies that investigated taurine as a single ingredient at dosages of < 1 g - 6 g, ranging from 10 to 15 min-to-2 h prior to exercise bout or chronic dose (7 days- 8 weeks) of consumption were included. Articles were excluded if taurine was not the primary or only ingredient in a supplement or food source, not published in peer-reviewed journals, if participants were older than 50 years, articles published before 1999, animal studies, or included participants with health issues. A total of 19 studies met the inclusion criteria for the review.

RESULTS

Key results include improvements in the following: VO₂max, time to exhaustion (TTE; n = 5 articles), 3 or 4 km time-trial (n = 2 articles), anaerobic performance (n = 7 articles), muscle damage (n = 3 articles), peak power (n = 2 articles), recovery (n = 1 article). Taurine also caused a change in metabolites: decrease in lactate, creatine kinase, phosphorus, inflammatory markers, and improved glycolytic/fat oxidation markers (n = 5 articles). Taurine dosing appears to be effective at ~ 1-3 g/day acutely across a span of 6-15 days (1-3 h before an activity) which may improve aerobic performance (TTE), anaerobic performance (strength, power), recovery (DOMS), and a decrease in metabolic markers (creatine kinase, lactate, inorganic phosphate).

CONCLUSIONS

Limited and varied findings prohibit definitive conclusions regarding the efficacy of taurine on aerobic and anaerobic performance and metabolic outcomes. There are mixed findings for the effect of taurine consumption on improving recovery from training bouts and/or mitigating muscle damage. The timing of taurine ingestion as well as the type of exercise protocol performed may contribute to the effectiveness of taurine as an ergogenic aid. More investigations are needed to better understand the potential effects of taurine supplementation on aerobic and anaerobic performance, muscle damage, metabolic stress, and recovery.

Taurine Supplementation Increases Post-Exercise Lipid Oxidation at Moderate Intensity in Fasted Healthy Males

Based on the fact that taurine can increase lipid metabolism, the objective of the present study was to evaluate the effects of different doses of acute taurine supplementation on lipid oxidation levels in healthy young men after a single bout of fasting aerobic exercise. A double-blind, acute, and crossover study design was conducted. Seventeen men (age 24.8 ± 4.07y; BMI: 23.9 ± 2.57 kg/m²) participated in the present study. Different doses of taurine (TAU) (3 g or 6 g) or placebo were supplemented 90 min before a single bout of fasting aerobic exercise (on a treadmill at 60% of VO₂ max). The subjects performed three trials, and each one was separated by seven days. Blood samples were collected at baseline and after the exercise protocol of each test to analyze plasma levels of glycerol and taurine. Lipid and carbohydrate oxidation were determined immediately after exercise for 15 min by indirect calorimetry. We observed that TAU supplementation (6 g) increased lipid oxidation (38%) and reduced the respiratory coefficient (4%) when compared to the placebo (p < 0.05). However, no differences in lipid oxidation were observed between the different doses of taurine (3 g and 6 g). For glycerol concentrations, there were no differences between trials. Six grams of TAU supplementation 90 min before a single bout of aerobic exercise in a fasted state was sufficient to increase the lipid oxidation post-exercise in healthy young men.

Oral taurine improves critical power and severe-intensity exercise tolerance

This study investigated the effects of acute oral taurine ingestion on: (1) the power-time relationship using the 3-min all-out test (3MAOT); (2) time to exhaustion (TTE) 5% > critical power (CP) and (3) the estimated time to complete (T_lim) a range of fixed target intensities. Twelve males completed a baseline 3MAOT test on a cycle ergometer. Following this, a double-blind, randomised cross-over design was followed, where participants were allocated to one of four conditions, separated by 72 h: TTE + taurine; TTE + placebo; 3MAOT + taurine; 3MAOT + placebo. Taurine was provided at 50 mg kg^-1, whilst the placebo was 3 mg kg^-1 maltodextrin. CP was higher (P < 0.05) in taurine (212 ± 36 W) than baseline (197 ± 40 W) and placebo (193 ± 35 W). Work end power was not affected by supplement (P > 0.05), yet TTE 5% > CP increased (P < 0.05) by 1.7 min after taurine (17.7 min) compared to placebo (16.0 min) and there were higher (P < 0.001) estimated T_lim across all work targets. Acute supplementation of 50 mg kg^-1 of taurine improved CP and estimated performance at a range of severe work intensities. Oral taurine can be taken prior to exercise to enhance endurance performance.

The Effect of Acute Taurine Ingestion on Human Maximal Voluntary Muscle Contraction

PURPOSE

This study aimed to examine the effect of taurine ingestion on maximal voluntary muscle torque and power in trained male athletes with different caffeine habits.

METHODS

Fourteen male athletes 21.8 ± 2.5 yr old were separated into caffeine and noncaffeine consumers to control for the effect of caffeine withdrawal on muscle function. On separate occasions, participants performed four isokinetic or three maximal isometric knee extensions with and without taurine (40 mg·kg body mass) after a double-blind, counterbalanced design. Muscle contractile performances were compared between the first sets as well as between the sets where these variables scored best.

RESULTS

In response to isokinetic contraction, taurine treatment in the noncaffeine consumers resulted in a significant fall in first (-16.1%; P = 0.013) and best peak torque (-5.0%; P = 0.016) as well as in first (-17.7%; P = 0.015) and best power output (-8.0%; P = 0.008). In the caffeine consumers deprived of caffeine, taurine intake improved best power (5.2%; P = 0.045). With respect to the isometric variables, there was a significant decrease in the first (-5.1%; P = 0.002) and best peak torque (-4.3%; P = 0.032) in the noncaffeine group, but no effect in the group of caffeine consumers deprived of caffeine. Taurine ingestion increased blood taurine levels but had no effect on plasma amino acid levels.

CONCLUSIONS

Taurine ingestion is detrimental to maximal voluntary muscle power and both maximal isokinetic and isometric peak torque in noncaffeine consumers, whereas taurine ingestion in caffeine-deprived caffeine consumers improves maximal voluntary muscle power but has no effect on other aspects of contractile performance.

ISSN exercise & sports nutrition review update: research & recommendations

Background

Sports nutrition is a constantly evolving field with hundreds of research papers published annually. In the year 2017 alone, 2082 articles were published under the key words ‘sport nutrition’. Consequently, staying current with the relevant literature is often difficult.

Methods

This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in 2004 and updated in 2010. It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. As such, this paper provides an overview of: 1.) How ergogenic aids and dietary supplements are defined in terms of governmental regulation and oversight; 2.) How dietary supplements are legally regulated in the United States; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of nutritional approaches to augment skeletal muscle hypertrophy and the potential ergogenic value of various dietary and supplemental approaches.

Conclusions

This updated review is to provide ISSN members and individuals interested in sports nutrition with information that can be implemented in educational, research or practical settings and serve as a foundational basis for determining the efficacy and safety of many common sport nutrition products and their ingredients.

The effects of taurine on repeat sprint cycling after low or high cadence exhaustive exercise in females

This study investigated the effects of taurine on repeated sprint exercise, performed after fixed incremental ramp exercise to exhaustion at isokinetic high (90 r/min) or low (50 r/min) cadences. In a double-blind, repeated measures design, nine females completed an incremental ramp test to volitional exhaustion, followed by 2 min active recovery and 6 × 10 s sprints on a cycle ergometer, in one of four conditions: high cadence (90 r/min) + taurine (50 mg/kg body mass); high cadence + placebo (3 mg/kg body mass maltodextrin); low cadence (50 r/min) + taurine; low cadence + placebo. Heart rate (HR) and blood lactate concentration B[La] were measured before and after the ramp test and after the sprints. Taurine lowered HR vs. placebo prior to the ramp test (P = 0.004; d = 2.1). There was an effect of condition on ramp performance (P < 0.001), with higher end-test power (d = 3.7) in taurine conditions. During repeated sprints, there was a condition × time interaction (P = 0.002), with higher peak sprint power in the placebo conditions compared to taurine (sprint 2-6; P < 0.05). B[La] was higher in taurine compared to placebo post-ramp (P = 0.004; d = 4.7). Taurine-lowered pre-exercise HR and improved incremental end-test power output, with subsequent detrimental effects on sprint performance, independent of cadence. Short endurance performance can be acutely enhanced after taurine ingestion but this effect might not be maintained across longer periods of exercise or induce the need for longer recovery periods.

The Effects of Caffeine, Taurine, or Caffeine-Taurine Coingestion on Repeat-Sprint Cycling Performance and Physiological Responses

Purpose: To investigate the effects of caffeine (C), taurine (T), caffeine and taurine coingestion (C +T), or placebo (P) on repeated Wingate cycling performance and associated physiological responses. Methods: Seven male team-sport players participated in a randomized, single-blind, crossover study, where they completed 3 Wingate tests, each separated by 2 min, an hour after ingesting: C (5 mg/kg body mass [BM]), T (50 mg/kg BM), C +T (5 mg/kg BM + 50 mg/kg BM), or P (5 mg/kg BM) in a gelatin capsule. Performance was measured on an ergometer, and blood lactate, perceived exertion, heart rate (HR), mean arterial pressure (MAP), and rate pressure product (RPP) were measured at rest (presupplement), baseline (1 h postsupplement), and during and after exercise. Results: Magnitude-based inferences revealed that all of the supplements increased (small to moderate, likely to very likely) mean peak power (MPP), peak power (PP), and mean power (MP) compared to P, with greater MPP, PP, and MP in T compared to C (small, possible). Intrasprint fatigue index (%FIIntra) was greater in T compared to P and C (moderate, likely), and %FIInter was lower in T compared to C (small, possible). C and C +T increased HR, MAP, and RPP compared to P and T at baseline (moderate to very large, likely to most likely); however, these only remained higher in C compared to all conditions in the final sprint. Conclusions: T elicited greater improvements in performance compared to P, C, or C +T while reducing the typical chronotropic and pressor effects of C.

Taurine supplementation can increase lipolysis and affect the contribution of energy systems during front crawl maximal effort

Taurine can affect the energy system metabolism, specifically the lipid metabolism, since an increase in lipid oxidation may promote carbohydrate savings. We hypothesized that taurine supplementation associated with high-intensity exercise could increase levels of lipolysis, benefiting swimmer performance. Nine male competitive swimmers performed two 400-m front crawl maximal efforts with a 1-week washout, and the athletes received 6 g of taurine (TAU) or placebo (PLA) supplementation 120 min before performing the effort. Oxygen consumption and the contribution of the energy systems were analyzed post effort using a Quark CPET gas analyzer. Blood samples were collected before, and 5 min post the effort for taurine and glycerol analysis. Immediately before and 3, 5, and 7 min post the effort, blood samples from the earlobe were collected to determine lactate levels. An increase of 159% was observed in taurine plasma levels 120 min post ingestion. Glycerol levels were higher in both groups post effort; however, the TAU condition promoted an 8% higher increase than the PLA. No changes were observed in swimmer performance or lactate levels; however, the percentage change in lactate levels (∆[La^-]) was different (TAU: 9.36 ± 2.78 mmol L^-1; PLA: 11.52 ± 2.19 mmol L^-1, p = 0.04). Acute taurine supplementation 120 min before performing a maximal effort did not improve swimmer performance; however, it increased glycerol plasma levels and reduced both the ∆[La^-] and lactic anaerobic system contribution.

Anaerobic Contribution Determined in Swimming Distances: Relation with Performance

Total anaerobic contribution (TAn) can be assessed by accumulated oxygen deficit, and through sum of glycolytic and phosphagen contribution which enable the evaluation of TAn without influences on mechanical parameters. However, little is known about the difference of TAn within swimming distances. Therefore, the objectives of the present study were to determine and compare the TAn in different performances using the backward extrapolation technique and amount of lactate accumulated during exercise, and relate it with swimming performance. Fourteen competitive swimmers performed five maximal front crawl swims of 50, 100, 200, 400, and 800 m. The total phosphagen (AnAl) and glycolytic (AnLa) contributions were assumed as the fast component of post-exercise oxygen consumption (EPOC_FAST) and amount of blood lactate accumulated during exercise, respectively. TAn was the sum of AnAl and AnLa. Significantly lower values of AnLa were observed in the 800 m (p < 0.01) than other distances. For AnAl, the 50 m performance presented the lowest values, followed by 100 and 800 m (p < 0.01). The highest values of AnAl were observed in the 200 and 400 m (p > 0.13). The TAn was significantly higher in the 200 and 400 m performances than observed at 50 and 800 m (p < 0.01). Anaerobic contributions were correlated with 50, 100, 200, and 400 m performances (p < 0.01). The AnAl contribution was not correlated with 400 m performance. Anaerobic parameters were not correlated with 800 m performance. In conclusion, the highest values of anaerobic contribution were observed in the 200 and 400 m distances. Moreover, TAn is important to performances below 400 m, and may be used in training routines.

Taurine supplementation improves economy of movement in the cycle test independently of the detrimental effects of ethanol

Taurine (TA) ingestion has been touted as blunting the deleterious effects of ethanol (ET) ingestion on motor performance. This study investigated the effects of ingestion of 0.6 mL·kg^-1 of ET, 6 grams of TA, and ethanol in combination with taurine (ET+TA) on economy of movement (EM) and heart rate (HR). Nine volunteers, five female (22 ± 3 years) and four male (26 ± 5 years), participated in a study that used a counterbalanced experimental design. EM and HR were measured for 6 min while the subjects were pedalling at a fixed load 10% below the anaerobic threshold. The blood alcohol concentration (BAC) was similar between ET and ET+TA treatments at 30 min after ingestion and after exercise (12.3 mmol·L^-1 vs. 13.7 mmol·L^-1, and 9.7 mmol • L^-1 vs 10.9 mmol·L^-1, respectively). EM was significantly different among treatments, with lower mL·W^-1 following ingestion of TA (-7.1%, p<0.001) than placebo and ET+TA (-2.45%, p=0.001) compared to ET. HR (bpm) was significantly (p<0.05) higher for ET (137 ± 14 bpm) than the other three treatments (placebo = 129 ± 14 bpm; TA = 127 ± 11 bpm; TA+ET = 133 ± 12 and ET = 137 ± 14 bpm). Taurine improved EM when compared to placebo or ET, and reduced HR when compared to ET. The combination of ET+TA also enhanced EM compared to placebo, and reduced HR in comparison to ET alone. Therefore, these findings indicate that taurine improves EM and counteracts ethanol-induced increases in HR during submaximal exercise.

Relationship between anaerobic capacity estimated using a single effort and 30-s tethered running outcomes

The purpose of the current study was to investigate the relationship between alternative anaerobic capacity method (MAOD_ALT) and a 30-s all-out tethered running test. Fourteen male recreational endurance runners underwent a graded exercise test, a supramaximal exhaustive effort and a 30-s all-out test on different days, interspaced by 48h. After verification of data normality (Shapiro-Wilk test), the Pearson’s correlation test was used to verify the association between the anaerobic estimates from the MAOD_ALT and the 30-s all-out tethered running outputs. Absolute MAOD_ALT was correlated with mean power (r = 0.58; P = 0.03), total work (r = 0.57; P = 0.03), and mean force (r = 0.79; P = 0.001). In addition, energy from the glycolytic pathway (E_[La^-_]) was correlated with mean power (r = 0.58; P = 0.03). Significant correlations were also found at each 5s interval between absolute MAOD_ALT and force values (r between 0.75 and 0.84), and between force values and E_[La^-_] (r between 0.73 to 0.80). In conclusion, the associations between absolute MAOD_ALT and the mechanical outputs from the 30-s all-out tethered running test evidenced the importance of the anaerobic capacity for maintaining force during the course of time in short efforts.

The sensitivity of the alternative maximal accumulated oxygen deficit method to discriminate training status

The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAOD_ALT) method to discriminate the "anaerobic" capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAOD_ALT. MAOD_ALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAOD_ALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg^-1) than in ET (56.8 ± 5.4 mL · kg^-1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg^-1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg^-1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAOD_ALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAOD_ALT was sensitive enough to distinguish the "anaerobic" capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants.

Acute LED irradiation does not change the anaerobic capacity and time to exhaustion during a high-intensity running effort: a double-blind, crossover, and placebo-controlled study : Effects of LED irradiation on anaerobic capacity and performance in running

The purpose of this study was to investigate the acute effects of photobiomodulation therapy using cluster light-emitting diodes (LEDT; 104 diodes) (wavelength 660 and 850 nm; energy density 1.5 and 4.5 J/cm(2); energy 60 J at each point; total energy delivered 600 J) on alternative maximal accumulated oxygen deficit (MAODALT) and time to exhaustion, during a high-intensity running effort. Fifteen moderately active and healthy males (age 25.1 ± 4.4 years) underwent a graded exercise test and two supramaximal exhaustive efforts at 115 % of the intensity associated with maximal oxygen uptake performed after acute LEDT or placebo irradiation in a double-blind, crossover, and placebo-controlled study design. The MAODALT was assumed as the sum of both oxygen equivalents estimated from the glycolytic and phosphagen metabolism pathways during each supramaximal effort. For the statistical analysis, a paired t test was used to determine differences between the treatments. The significance level was assumed as 95 %. In addition, a qualitative analysis was used to determine the magnitude of differences between groups. No significant differences were found for the values of oxygen equivalents from each energetic metabolism (P ≥ 0.28), for MAODALT values between the LEDT and placebo conditions (P ≥ 0.27), or for time to exhaustion (P = 0.80), except for the respiratory exchange ratio (P = 0.01). The magnitude-based inference of effect size reported only a possibly negative effect of photobiomodulation on MAODALT when expressed in units relative to body mass and on the glycolysis pathway (26 %). In summary, LEDT after a high-intensity running effort did not alter the MAODALT, metabolic energy pathways, or high-intensity running performance.