Exercise-induced oxidative stress: the effects of β-alanine supplementation in women

The purpose of this study was to evaluate the effects of β-alanine supplementation on markers of oxidative stress. Twenty-four women (age: 21.7±2.1 years; VO2max: 2.6±0.3 l min(-1)) were randomly assigned, in a double-blind fashion, to a β-alanine (BA, 2×800 mg tablets, 3× daily; CarnoSyn?; n=13) or placebo (PL, 2×800 mg maltodextrin tablets, 3× daily; n=11) group. A graded oxygen consumption test (VO2max) was performed to evaluate VO2max, time to exhaustion, ventilatory threshold and establish peak velocity (PV). A 40-min treadmill run was used to induce oxidative stress. Total antioxidant capacity, superoxide dismutase, 8-isoprostane (8ISO) and reduced glutathione were measured. Heart rate and ratings of perceived exertion were recorded during the 40 min run. Separate three- [4×2×2; acute (base vs. IP vs. 2 vs. 4 h)×chronic (pre- vs. post-)×treatment (BA vs. PL)] and two- [2×2; time (pre-supplement vs. post-supplement)×treatment (BA vs. PL)] way ANOVAs were used for analyses. There was a significant increase in VO2max (p=0.009), independent of treatment, with no significant changes in TTE (p=0.074) or VT (p=0.344). Ratings of perceived exertion values were significantly improved from pre- to post-supplementation for the BA group only at 40 min (p=0.02). The ANOVA model demonstrated no significant treatment effects on oxidative stress. The chronic effects of BA supplementation demonstrated little antioxidant potential, in women, and little influence on aerobic performance assessments.     

The effect of creatine on treadmill running with high-intensity intervals

To determine whether creatine monohydrate supplementation would improve performance during a submaximal treadmill run interspersed with high-intensity intervals, 15 college soccer players (8 women, 7 men) received either creatine or a maltodextrin placebo at 0.3 g.kg body mass per day for 6 days. The speed of the treadmill was constant at 160.8 m.min, and every 2 minutes the grade was elevated to 15%. Each hill segment was 1 minute long. At the end of the 20-minute protocol, the treadmill was again elevated to 15% and held there until volitional exhaustion occurred. There was a significant treatment effect of creatine supplementation on body mass (p < 0.05) in the men; however, no significant differences were observed in the women (p > 0.05). There were no treatment effects (p > 0.05) on time to exhaustion, ratings of perceived exertion, or blood lactate concentration. There was a tendency for blood lactate levels to be lower after short-term creatine supplementation in the women, but this was not statistically significant. Based on these results, it appears that creatine supplementation does not improve performance in submaximal running interspersed with high-intensity intervals.     

Influence of training status on high-intensity intermittent performance in response to β-alanine supplementation

Recent investigations have suggested that highly trained athletes may be less responsive to the ergogenic effects of β-alanine (BA) supplementation than recreationally active individuals due to their elevated muscle buffering capacity. We investigated whether training status influences the effect of BA on repeated Wingate performance. Forty young males were divided into two groups according to their training status (trained: T, and non-trained: NT cyclists) and were randomly allocated to BA and a dextrose-based placebo (PL) groups, providing four experimental conditions: NTPL, NTBA, TPL, TBA. BA (6.4 g day^?1) or PL was ingested for 4 weeks, with participants completing four 30-s lower-body Wingate bouts, separated by 3 min, before and after supplementation. Total work done was significantly increased following supplementation in both NTBA (p = 0.03) and TBA (p = 0.002), and it was significantly reduced in NTPL (p = 0.03) with no difference for TPL (p = 0.73). BA supplementation increased mean power output (MPO) in bout 4 for the NTBA group (p = 0.0004) and in bouts 1, 2 and 4 for the TBA group (p ≤ 0.05). No differences were observed in MPO for NTPL and TPL. BA supplementation was effective at improving repeated high-intensity cycling performance in both trained and non-trained individuals, highlighting the efficacy of BA as an ergogenic aid for high-intensity exercise regardless of the training status of the individual.     

Effects of β-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women

Summary. This study examined the effects of 28 days of β-alanine supplementation on the physical working capacity at fatigue threshold (PWC_FT), ventilatory threshold (VT), maximal oxygen consumption ( O_2-MAX), and time-to-exhaustion (TTE) in women. Twenty-two women (age ± SD 27.4 ± 6.1 yrs) participated and were randomly assigned to either the β-alanine (CarnoSyn™) or Placebo (PL) group. Before (pre) and after (post) the supplementation period, participants performed a continuous, incremental cycle ergometry test to exhaustion to determine the PWC_FT, VT, O_2-MAX, and TTE. There was a 13.9, 12.6 and 2.5% increase (p < 0.05) in VT, PWC_FT, and TTE, respectively, for the β-alanine group, with no changes in the PL (p > 0.05). There were no changes for O_2-MAX (p > 0.05) in either group. Results of this study indicate that β-alanine supplementation delays the onset of neuromuscular fatigue (PWC_FT) and the ventilatory threshold (VT) at submaximal workloads, and increase in TTE during maximal cycle ergometry performance. However, β-alanine supplementation did not affect maximal aerobic power ( O_2-MAX). In conclusion, β-alanine supplementation appears to improve submaximal cycle ergometry performance and TTE in young women, perhaps as a result of an increased buffering capacity due to elevated muscle carnosine concentrations.     

Effects of β-alanine supplementation on performance and body composition in collegiate wrestlers and football players

The purpose of this study was to examine the effectiveness of β-alanine as an ergogenic aid in tests of anaerobic power output after 8 weeks of high-intensity interval, repeated sprint, and resistance training in previously trained collegiate wrestlers (WR) and football (FB) players. Twenty-two college WRs (19.9 ± 1.9 years, age ± SD) and 15 college FB players (18.6 ± 1.5 years) participated in this double-blind, placebo-controlled study. Each subject ingested either 4 g·d β-alanine or placebo in powdered capsule form. Subjects were tested pre and posttreatment in timed 300-yd shuttle, 90° flexed-arm hang (FAH), body composition, and blood lactate after 300-yd shuttle. Although not statistically significant (p > 0.05) subjects taking β-alanine achieved more desirable results on all tests compared to those on placebo. Performance improvements were greatest in the FB supplement group, decreasing 300 shuttle time by 1.1 seconds (vs. 0.4-second placebo) and increasing FAH (3.0 vs. 0.39 seconds). The wrestlers, both placebo and supplement, lost weight (as was the goal, i.e., weight bracket allowance); however, the supplement group increased lean mass by 1.1 lb, whereas the placebo group lost lean mass (-0.98 lb). Both FB groups gained weight; however, the supplement group gained an average 2.1-lb lean mass compared to 1.1 lb for placebo. β-Alanine appears to have the ability to augment performance and stimulate lean mass accrual in a short amount of time (8 weeks) in previously trained athletes. Training regimen may have an effect on the degree of benefit from β-alanine supplementation.     

Magnesium homeostasis during high-intensity anaerobic exercise in men

This study was conducted to determine whether short-term, high-intensity anaerobic exercise alters Mg homeostasis. Thirteen men performed intermittent bouts of treadmill running at 90% of their predetermined maximum O2 uptake until exhaustion on one occasion during a week in which all men were consuming a standard diet (115 mg Mg/1,000 kcal). Plasma and erythrocyte Mg concentrations and peripheral blood mononuclear cell Mg content were measured before and after the exercise. Complete 24-h urine collections were obtained on control days, on the day of exercise, and on the day after exercise. Exercise induced a transient but significant decrease in plasma Mg content (-6.8%; P less than 0.01); over 85% of the loss could be accounted for by a shift to the erythrocytes. Significant increases in urinary excretion of Mg were observed on the day of exercise (131.5 +/- 6.8 mg/day) compared with control days (108 +/- 6.6 mg/day), with the percent increase correlating with postexercise blood lactate concentration (r = 0.68; P less than 0.01) and oxygen consumption during recovery (r = 0.84; P less than 0.001). The data indicate that high-intensity anaerobic exercise induces intercompartmental Mg shifts in blood that return to preexercise values within 2 h and urinary losses on the day of exercise that return to base line the day after exercise. It is postulated that the exercise-induced increase in Mg excretion may depend on the intensity of the exercise, and the relative contribution of anaerobic metabolism to the total energy expended during exercise.     

Effect of beta-alanine supplementation on muscle carnosine concentrations and exercise performance

High-intensity exercise results in reduced substrate levels and accumulation of metabolites in the skeletal muscle. The accumulation of these metabolites (e.g. ADP, Pi and H⁺) can have deleterious effects on skeletal muscle function and force generation, thus contributing to fatigue. Clearly this is a challenge to sport and exercise performance and, as such, any intervention capable of reducing the negative impact of these metabolites would be of use. Carnosine (β-alanyl-l-histidine) is a cytoplasmic dipeptide found in high concentrations in the skeletal muscle of both vertebrates and non-vertebrates and is formed by bonding histidine and β-alanine in a reaction catalysed by carnosine synthase. Due to the pKa of its imidazole ring (6.83) and its location within skeletal muscle, carnosine has a key role to play in intracellular pH buffering over the physiological pH range, although other physiological roles for carnosine have also been suggested. The concentration of histidine in muscle and plasma is high relative to its K _m with muscle carnosine synthase, whereas β-alanine exists in low concentration in muscle and has a higher K _m with muscle carnosine synthase, which indicates that it is the availability of β-alanine that is limiting to the synthesis of carnosine in skeletal muscle. Thus, the elevation of muscle carnosine concentrations through the dietary intake of carnosine, or chemically related dipeptides that release β-alanine on absorption, or supplementation with β-alanine directly could provide a method of increasing intracellular buffering capacity during exercise, which could provide a means of increasing high-intensity exercise capacity and performance. This paper reviews the available evidence relating to the effects of β-alanine supplementation on muscle carnosine synthesis and the subsequent effects on exercise performance. In addition, the effects of training, with or without β-alanine supplementation, on muscle carnosine concentrations are also reviewed.     

Acute arginine supplementation fails to improve muscle endurance or affect blood pressure responses to resistance training

Dietary supplement companies claim that arginine supplements acutely enhance skeletal muscular endurance. The purpose of this study was to determine whether acute arginine α-ketoglutarate supplementation (AAKG) will affect local muscle endurance of the arm and shoulder girdle or the blood pressure (BP) response to anaerobic exercise. Twelve trained college-aged men (22.6 ± 3.8 years) performed 2 trials of exercise separated by at least 1 week. At 4 hours before, and 30 minutes before exercise, a serving of an AAKG supplement (3,700 mg arginine alpha-ketoglutarate per serving) or placebo was administered. Resting BP was assessed pre-exercise after 16 minutes of seated rest, and 5 and 10 minutes postexercise. Three sets each of chin-ups, reverse chin-ups, and push-ups were performed to exhaustion with 3 minutes of rest between each set. Data were analyzed using repeated-measures analysis of variance and paired t-tests. The AAKG supplementation did not improve muscle endurance or significantly affect the BP response to anaerobic work. Subjects performed fewer total chin-ups (23.75 ± 6.38 vs. 25.58 ± 7.18) and total trial repetitions (137.92 ± 28.18 vs. 141.08 ± 28.57) in the supplement trial (p ≤ 0.05). Subjects executed fewer reverse chin-ups (5.83 ± 1.85 vs. 6.75 ± 2.09) during set 2 after receiving the supplement as compared to the placebo (p < 0.05). Because AAKG supplementation may hinder muscular endurance, the use of these supplements before resistance training should be questioned.     

Effect of beta-alanine supplementation on repeated sprint performance during the Loughborough Intermittent Shuttle Test

The aim of this study was to examine the effect of β-alanine supplementation on repeated sprint performance during an intermittent exercise protocol designed to replicate games play. Sixteen elite and twenty non-elite game players performed the Loughborough Intermittent Shuttle Test (LIST) on two separate occasions. Trials were separated by 4 weeks of supplementation with either β-alanine (BA) or maltodextrin (MD). There was no deterioration in sprint times from Set 1 to Set 6 of the LIST in either group prior to supplementation (elite: P=0.92; non-elite: P=0.12). Neither BA nor MD supplementation affected sprint times. Blood lactate concentrations were elevated during exercise in both groups, with no effect of supplementation. β-Alanine supplementation did not significantly improve sprint performance during the LIST. Neither group showed a performance decrement prior to supplementation, which might have masked any benefit from increased muscle buffering capacity due to β-alanine supplementation.     

Do compression garments enhance the active recovery process after high-intensity running?

Lovell, DI, Mason, DG, Delphinus, EM, and McLellan, CP. Do compression garments enhance the active recovery process after high-intensity running? J Strength Cond Res 25(12): 3264-3268, 2011-This study examined the effect of wearing waist-to-ankle compression garments (CGs) on active recovery after moderate- and high-intensity submaximal treadmill running. Twenty-five male semiprofessional rugby league players performed two 30-minute treadmill runs comprising of six 5-minute stages at 6 km·h, 10 km·h, approximately 85% VO(2)max, 6 km·h as a recovery stage followed by approximately 85% VO(2)max and 6 km·h wearing either CGs or regular running shorts in a randomized counterbalanced order with each person acting as his own control. All stages were followed by 30 seconds of rest during which a blood sample was collected to determine blood pH and blood lactate concentration [La]. Expired gases and heart rate (HR) were measured during the submaximal treadmill tests to determine metabolic variables with the average of the last 2 minutes used for data analysis. The HR and [La] were lower (p ≤ 0.05) after the first and second 6 km·h recovery bouts when wearing CGs compared with when wearing running shorts. The respiratory exchange ratio (RER) was higher and [La] lower (p ≤ 0.05) after the 10 km·h stage, and only RER was higher after both 85% VO(2)max stages when wearing CGs compared with when wearing running shorts. There was no difference in blood pH at any exercise stage when wearing the CGs and running shorts. The results of this study indicate that the wearing of CGs may augment the active recovery process in reducing [La] and HR after high-intensity exercise but not effect blood pH. The ability to reduce [La] and HR has important consequences for many sports that are intermittent in nature and consist of repeated bouts of high-intensity exercise interspersed with periods of low-intensity exercise or recovery.     

Anaerobic capacity determined by maximal accumulated O2 deficit

We present a method for quantifying the anaerobic capacity based on determination of the maximal accumulated O2 deficit. The accumulated O2 deficit was determined for 11 subjects during 5 exhausting bouts of treadmill running lasting from 15 s to greater than 4 min. The accumulated O2 deficit increased with the duration for exhausting bouts lasting up to 2 min, but a leveling off was found for bouts lasting 2 min or more. Between-subject variation in the maximal accumulated O2 deficit ranged from 52 to 90 ml/kg. During exhausting exercise while subjects inspired air with reduced O2 content (O2 fraction = 13.5%), the maximal O2 uptake was 22% lower, whereas the accumulated O2 deficit remained unchanged. The precision of the method is 3 ml/kg. The method is based on estimation of the O2 demand by extrapolating the linear relationship between treadmill speed and O2 uptake at submaximal intensities. The slopes, which reflect running economy, varied by 16% between subjects, and the relationships had to be determined individually. This can be done either by measuring the O2 uptake at a minimum of 10 different submaximal intensities or by two measurements close to the maximal O2 uptake and by making use of a common Y-intercept of 5 ml.kg-1.min-1. By using these individual relationships the maximal accumulated O2 deficit, which appears to be a direct quantitative expression of the anaerobic capacity, can be calculated after measuring the O2 uptake during one exhausting bout of exercise lasting 2-3 min.     

Determinants of muscle carnosine content

The main determinant of muscle carnosine (M-Carn) content is undoubtedly species, with, for example, aerobically trained female vegetarian athletes [with circa 13 mmol/kg dry muscle (dm)] having just 1/10th of that found in trained thoroughbred horses. Muscle fibre type is another key determinant, as type II fibres have a higher M-Carn or muscle histidine containing dipeptide (M-HCD) content than type I fibres. In vegetarians, M-Carn is limited by hepatic synthesis of β-alanine, whereas in omnivores this is augmented by the hydrolysis of dietary supplied HCD's resulting in muscle levels two or more times higher. β-alanine supplementation will increase M-Carn. The same increase in M-Carn occurs with administration of an equal molar quantity of carnosine as an alternative source of β-alanine. Following the cessation of supplementation, M-Carn returns to pre-supplementation levels, with an estimated t1/2 of 5-9 weeks. Higher than normal M-Carn contents have been noted in some chronically weight-trained subjects, but it is unclear if this is due to the training per se, or secondary to changes in muscle fibre composition, an increase in β-alanine intake or even anabolic steroid use. There is no measureable loss of M-Carn with acute exercise, although exercise-induced muscle damage may result in raised plasma concentrations in equines. Animal studies indicate effects of gender and age, but human studies lack sufficient control of the effects of diet and changes in muscle fibre composition.     

Reliability of the Lode Excalibur Sport Ergometer and applicability to Computrainer electromagnetically braked cycling training device

New technology allows cyclists to train via power output (PO) in addition to heart rate (HR). For those athletes undertaking seasonal laboratory testing (e.g., Vo(2), lactate threshold), it is imperative that athletes be able to directly apply this information to their training device. We examined the reliability of a standardized laboratory ergometer (Lode Excalibur Sport) and its applicability to an electromagnetically braked ergometer (Computrainer) in 2 phases. Phase I (n = 12) examined the reliability of the Lode. Phase II (n = 14) compared the Lode to the Computrainer using a randomized, counterbalance assignment. Following warm-up, each trial started at 100 W, progressing 50 W every 3 minutes to exhaustion. Outcomes were time-to-exhaustion (TTE), peak PO (W) (PO(peak)), peak HR (HR(peak)), and ventilatory (VT) and respiratory compensation (RCP) thresholds. We used a repeated measures analysis of variance (ANOVA), Tukey post hoc analysis, regression analysis, Bland-Altman plots, and coefficient of variation (CV) analysis for each variable. During phase I, we found no significant difference for any variable, minimal dispersion of Vo(2) during Bland-Altman analysis, and a low CV at each test stage (相似文献   

uHIIT显著改善男性减脂效果

本研究旨在探讨以心率控制方式进行12周的上坡高强度间歇训练(uphill high-intensityinterval training,uHIIT)和中等水平强度持续训练(moderate-intensity continuous training, MCT)对于中年过重肥胖男性的身体组成(体脂肪百分比和净体重)、代谢症候指标(安静血压,血糖,高低密度脂蛋白胆固醇,总胆固醇和甘油三脂)及心肺耐力指标(最大摄氧量,无氧阈值和力竭时间)的影响。本研究通过对25位中年过重肥胖男性(BMI>24)训练前后的身体组成与代谢症候指标进行检测,并进行渐增强度测验,以评估心肺耐力指标。前测后,受试者随机分配至uHIIT组(心率控制强度为90%HRmax,运动2 min休息1 min共7次进行约20 min)、MCT组(心率控制强度为65%～70%HR_max,运动约40 min)与控制组。进行每周3次为期12周的训练后,再接受相同的测试1次。研究显示,相较于控制组,uHIIT组与MCT组的最大摄氧量(V4O_2max)、无氧阈值、力竭时间、臀部脂肪皆显著改善,且uHIIT组在V4O_2max增加量上显著高于MCT组,仅有uHIIT组的血压、体脂肪百分比和腿部脂肪显著改善。本研究表明,uHIIT与MCT皆可改善中年肥胖男性心肺耐力,同时uHIIT对于减脂与血压的改善较为显著,但其余代谢指标受到运动的影响较小,减脂效果上uHIIT的运动效益优于MCT,建议运动时应重视运动强度。     

Predicting maximal aerobic capacity (VO2max) from the critical velocity test in female collegiate rowers

The objective of this study was to examine the relationship between the critical velocity (CV) test and maximal oxygen consumption (VO2max) and develop a regression equation to predict VO2max based on the CV test in female collegiate rowers. Thirty-five female (mean ± SD; age, 19.38 ± 1.3 years; height, 170.27 ± 6.07 cm; body mass, 69.58 ± 0.3 1 kg) collegiate rowers performed 2 incremental VO2max tests to volitional exhaustion on a Concept II Model D rowing ergometer to determine VO2max. After a 72-hour rest period, each rower completed 4 time trials at varying distances for the determination of CV and anaerobic rowing capacity (ARC). A positive correlation was observed between CV and absolute VO2max (r = 0.775, p < 0.001) and ARC and absolute VO2max (r = 0.414, p = 0.040). Based on the significant correlation analysis, a linear regression equation was developed to predict the absolute VO2max from CV and ARC (absolute VO2max = 1.579[CV] + 0.008[ARC] - 3.838; standard error of the estimate [SEE] = 0.192 L·min(-1)). Cross validation analyses were performed using an independent sample of 10 rowers. There was no significant difference between the mean predicted VO2max (3.02 L·min(-1)) and the observed VO2max (3.10 L·min(-1)). The constant error, SEE and validity coefficient (r) were 0.076 L·min(-1), 0.144 L·min(-1), and 0.72, respectively. The total error value was 0.155 L·min(-1). The positive relationship between CV, ARC, and VO2max suggests that the CV test may be a practical alternative to measuring the maximal oxygen uptake in the absence of a metabolic cart. Additional studies are needed to validate the regression equation using a larger sample size and different populations (junior- and senior-level female rowers) and to determine the accuracy of the equation in tracking changes after a training intervention.     

Acute effects of small-sided games combined with running drills on internal and external loads in young soccer players

The purpose of this study was to compare the effects of regular small-sided games (SSGreg) and SSGs combined with running drills (SSGcom) on players’ internal and external loads. Eighteen young male soccer players (average age: 18.2 ± 0.5 years) participated in 3 vs. 3 and 4 vs. 4 games, under both SSGreg and SSGcom conditions. SSGreg bouts were played for 4 minutes without additional running drills, while SSGcom bouts consisted of 3 min 30 s SSG and 15 s running before and after the bout, making the duration of each bout 4 minutes. During all SSGs, measurements of heart rate (HR) responses as well as distances covered in four different speed zones – walking (WLK), low-intensity (LIR), moderate-intensity (MIR) and high-intensity running (HIR) – were recorded. Technical characteristics were monitored during the SSGs, and the rating of perceived exertion (RPE) and blood lactate (La-) responses were determined at the end of each SSG condition. Compared to the SSGreg in both 3 vs. 3 and 4 vs. 4 formats, the SSGcom condition resulted in higher La- and RPE responses (p < 0.05), greater distance covered at MIR and HIR speeds and greater total distance (p < 0.05). The results of this study show that replacing 30 s within the 4-min bouts of SSGs (both 3- and 4-a-side) by 2 x 15 s of running drills is effective in increasing internal (La- and RPE) and external loads (MIR and HIR) without a significant decrease in total passes and successful passes in young soccer players.     

The role of anaerobic ability in middle distance running performance

The purpose of this study was to assess the relationship between anaerobic ability and middle distance running performance. Ten runners of similar performance capacities (5 km times: 16.72, SE 0.2 min) were examined during 4 weeks of controlled training. The runners performed a battery of tests each week [maximum oxygen consumption (VO2max), vertical jump, and Margaria power run] and raced 5 km three times (weeks 1, 2, 4) on an indoor 200-m track (all subjects competing). Regression analysis revealed that the combination of time to exhaustion (TTE) during the VO2max test (r2 = 0.63) and measures from the Margaria power test (W.kg-1, r2 = 0.18; W, r2 = 0.05) accounted for 86% of the total variance in race times (P less than 0.05). Regression analysis demonstrated that TTE was influenced by both anaerobic ability [vertical jump, power (W.kg-1) and aerobic capacity (VO2max, ml.kg-1.min-1)]. These results indicate that the anaerobic systems influence middle distance performance in runners of similar abilities.     

Effect of nutritionally enriched coffee consumption on aerobic and anaerobic exercise performance

The purpose of this study was to compare nutritionally enriched JavaFit coffee (JF) to commercially available decaffeinated coffee (P) with regard to impact on endurance and anaerobic power performance in a physically active, college-aged population. Ten subjects (8 men, 2 women) performed two 30-second Wingate anaerobic power tests and 2 cycle ergometer tests (75% VO2 max) to exhaustion. Mean VO2 was measured during each endurance exercise protocol. Excess postexercise oxygen consumption (EPOC) and respiratory exchange ratio (RER) were recorded for 30 minutes following all exercise sessions. Area under the curve analysis was used to compare EPOC between JF and P for all exercise sessions. No differences were seen between JF and P in any of the power performance measures. However, time to exhaustion was significantly (p = 0.05) higher in JF (35.3 +/- 15.2 minutes) compared with P (27.3 +/- 10.7 minutes). No difference between JF and P were seen in EPOC in either the aerobic or anaerobic exercise sessions. A significant (p < 0.05) difference in average 30-minute postanaerobic power exercise RER was seen between JF (0.87 +/- 0.04) and P (0.83 +/- 0.03), but not following endurance exercise. A nutritionally-enriched coffee beverage appears to enhance time to exhaustion during aerobic exercise, but does not provide an ergogenic benefit during anaerobic exercise.