High-intensity Exercise Performance Research Articles

Effects of High-Intensity Inspiratory Muscle Warm-Up on High-Intensity Exercise Performance and Muscle Oxygenation.

An inspiratory muscle warm-up (IMW) improves inspiratory muscle function, but the effects of high-intensity exercise are inconsistent. We aimed to determine the effects of high-intensity IMW on high-intensity exercise performance and muscle oxygenation. Ten healthy men (maximal oxygen uptake [V˙O2max] 52.2 [5.0]mL·kg-1·min-1) performed constant-load exercise to exhaustion on a cycle ergometer at V˙O2max under 2 IMW conditions: a placebo condition (PLA) and a high-intensity IMW condition (HIGH). The inspiratory loads were set at 15% and 80% of maximal inspiratory pressure, respectively. Maximal inspiratory pressure was measured before and after IMW. Oxyhemoglobin was measured in the vastus lateralis by near-infrared spectroscopy during exercise. Rating of perceived exertion (RPE)for a leg was measured after 1 and 2minutes of exercise. Exercise tolerance was significantly higher under HIGH than PLA (228 [49]s vs 218 [49]s, P = .003). Maximal inspiratory pressure was significantly increased by IMW under HIGH (from 125 [20] to 136 [25] cm H2O, P = .031). Oxyhemoglobin was significantly higher under HIGH than PLA at 80% of the total duration of exercise (P = .048). RPE for the leg was significantly lower under HIGH than PLA after 2minutes of exercise (P = .019). Given that oxyhemoglobin is an index of local oxygen supply, the results of this study suggest that high-intensity IMW increases the oxygen supply to active limbs. It may also reflect a reduction in RPE in the leg. In addition, high-intensity IMW may improve exercise performance.

Effects of In-Exercise Carbohydrate Supplementation on Prolonged High-Intensity Exercise Performance in Oral Contraceptive Users.

To examine the impact of oral contraceptive (OC) phases on performance, physiological, and subjective responses to prolonged, intensive exercise when carbohydrate (CHO) stores are reduced. Ten well-trained female cyclists using monophasic OC completed 4 identical trials (>150min) under conditions of in-trial 60-g·h-1 CHO supplementation (CHO+) or placebo (CHO-) during the sugar- (SUG) and active-pill (ACT) phases of their OC cycle. Each trial comprised two 400-kcal time trials (TT) separated by 1hour of submaximal cycling at first ventilatory threshold. Change in completion time from TT1 to TT2 was minimized in CHO+ compared with CHO- (4.06 [2.55] vs 6.08 [5.33]min; P = .019, effect size = -0.36). An interaction effect of OC and CHO was observed for time to complete TT (P = .006), mean TT power (P = .002), mean TT heart rate (P = .002), and posttrial emotional balance (P = .020) and negative emotional state (P = .033). In ACT, mean TT power and heart rate were higher in CHO+ when compared with CHO-, resulting in faster TTs in CHO+ and improved posttrial emotional well-being. When CHO was not supplemented, TT power and heart rate were higher in SUG when compared with ACT, resulting in faster TTs in SUG and improved posttrial emotional balance. CHO depletion during ACT negatively influenced TT performance and emotional well-being when compared with SUG. Irrespective of OC pill phase, CHO supplementation should be prioritized to sustain performance and improve postexercise recovery-stress balance.

The influence of low resistance respiratory muscle training on pulmonary function and high intensity exercise performance

Background/objectivesRespiratory muscle training (RMT) was recognized as an effective means to improve respiratory muscle (RM) strength and enhance exercise performance. The purpose of this study was to examine the effect of low-intensity RMT on RM strength, pulmonary function, and performance. MethodsFourteen healthy active adults were assigned randomly to either a training or placebo group. The training group completed six weeks of RMT, which consisted of a first week, 1 set of 15 min/d, 5 d/wk at 10–25% of maximal inspiratory pressure (PImax), and the remaining 5 weeks, 2 sets of 15 min/d, 5 d/wk, at 30% PImax. The placebo group followed the same protocol but with almost no additional ventilatory resistance. Measurement of RM strength and endurance, spirometry, and endurance exercise performance were obtained before and after the RMT program. ResultsIn the training group, PImax (+14%) and maximal expiratory pressure (PEmax, +27%), forced vital capacity (FVC, +3.6%), maximal oxygen uptake (VO2max, +11%), and time to exhaustion (Tlim90%, +25%) increased significantly from baseline values (P < 0.05). No significant changes were observed in the placebo group. Also, no significant interaction in maximum voluntary ventilation (MVV12), minute ventilation (VE), and respiratory rate (RR) were detected. ConclusionsThese data suggest that low-intensity RMT is an effective tool to improve RM strength, pulmonary elastic properties and endurance exercise performance.

Effects of acute and multi-day low-dose sodium bicarbonate intake on high-intensity endurance exercise performance in male recreational cyclists.

This study aimed to compare the effects of acute and multi-day low-dose sodium bicarbonate (SB)intake on high-intensity endurance exercise performance. In a randomized, double-blind, cross-over design, twelve recreational male cyclists (age: 31.17 ± 4.91years; O2peak: 47.98 ± 7.68ml·kg-1·min-1) completed three endurance performance tests following acute SB (ASB, 0.2g·kg-1 SB), multi-day SB (MSB, 0.2g·kg-1·day-1 SB for four days), and placebo (PLA) intake. The high-intensity endurance performance was assessed with a cycling exercise test, wherein participants cycled on a bicycle ergometer at 95% of the predetermined anaerobic threshold for 30min, followed by a time-to-exhaustion test at 110% of the anaerobic threshold. Data were analyzed using one-way and two-way repeated-measures ANOVA. Significant main effects of supplementation protocol were evident in pre-exercise bicarbonate concentrations (F = 27.93; p < 0.01; partial eta squared (η2) = 0.72; false discovery rate (FDR)-adjusted p value = 0.001). Prior to performance test, blood bicarbonate concentrations were significantly higher in MSB (25.78 ± 1.63mmol·L-1[95% CI 26.55-28.44] (p < 0.001; FDR-adjusted p value = 0.001)) and ASB (27.49 ± 1.49mmol·L-1 [95% CI 24.75-26.81] (p < 0.001; FDR-adjusted p value = 0.007)) compared to PLA (23.75 ± 1.40mmol·L-1 [95% CI 22.86 to 24.64]). Time-to-exhaustion increased in MSB (54.27 ± 9.20min [95% CI 48.43-60.12]) compared to PLA (49.75 ± 10.80min [95% CI 42.89-56.62]) (p = 0.048); however, this increase in MSB did not reach the significance threshold of 1% FDR (FDR-adjusted p value = 0.040). No significant difference was noted in exhaustion times between ASB (51.15 ± 8.39min [95% CI 45.82-56.48]) and PLA (p > 0.05). Both acute and multi-day administration of low-dose SB improves buffering system in cyclists; nevertheless, neither intervention demonstrates sufficient efficacy in enhancing high-intensity endurance performance.

Yohimbine Ingestion Mitigates Morning-Associated Decrements in High-Intensity Exercise Performance

Exercise performance tends to suffer during the morning compared to the evening, which may decrease potential training adaptations. Currently, it is unclear how nutritional interventions may affect this phenomenon and whether supplementation may allow for the attainment of optimal performance regardless of the time of day. The purpose of this study was to investigate the effects of acute yohimbine ingestion on morning-associated decrements in performance and psychophysiological responses to exercise. Physically active females (n = 16) were recruited to participate in three total visits, each with a different treatment: (1) placebo-morning (PL-AM), (2) yohimbine-morning (YHM-AM; oral 2.5 mg), and (3) placebo-afternoon (PM). The morning and afternoon visits occurred between 7:00–8:00 h and 16:00–17:00 h, respectively. The experimental treatments in the morning were ingested 20 min prior to capillary blood collection, which was completed pre- and post-exercise. Following a warm-up, participants completed a 2000 m time trial on a rowing ergometer. Power output, heart rate (HR), and rating of perceived exertion (RPE) were recorded every minute. Time to competition (TTC) and subjective energy, focus, and alertness were documented post-exercise. Pre- and post-exercise blood lactate (La) and plasma hypoxanthine (HX) levels were also assessed. The trials were separated by a 48 h washout period. The results showed that power output (p = 0.010) was lower and TTC (p = 0.003) was significantly slower with PL-AM compared to PM. Furthermore, YHM-AM resulted in higher power output (p = 0.035) and faster TTC (p = 0.007) compared to PL-AM, with no differences compared to PM (p &gt; 0.05). Post-exercise La was significantly lower with YHM-AM compared to PL-AM (p = 0.046) and PM (p = 0.001). Pre-exercise plasma HX, as measured via conversion to xanthine, was significantly higher with PM (p = 0.039), while the levels trended higher with YHM-AM (p = 0.060) compared to PL-AM. Subjective energy was higher with YHM-AM (p = 0.045) and PM (p = 0.009) compared to PL-AM, while alertness was only higher for YHM-AM compared to PL-AM (p = 0.045). No statistical differences between the treatments were found for RPE or HR (p &gt; 0.05). These findings indicate that YHM ingestion attenuates performance decrements in the morning. Improvements in performance may be underpinned by improved feelings of energy and alterations in metabolism. Practically, YHM may represent an effective ergogenic aid to combat a lack of energy and low performance during the morning.

Modelling human endurance: power laws vs critical power

The power–duration relationship describes the time to exhaustion for exercise at different intensities. It is believed to be a “fundamental bioenergetic property of living systems” that this relationship is hyperbolic. Indeed, the hyperbolic (a.k.a. critical-power) model which formalises this belief is the dominant tool for describing and predicting high-intensity exercise performance, e.g. in cycling, running, rowing or swimming. However, the hyperbolic model is now the focus of a heated debate in the literature because it unrealistically represents efforts that are short (< 2 min) or long (> 15 min). We contribute to this debate by demonstrating that the power–duration relationship is more adequately represented by an alternative, power-law model. In particular, we show that the often-observed good fit of the hyperbolic model between 2 and 15 min should not be taken as proof that the power–duration relationship is hyperbolic. Rather, in this range, a hyperbolic function just happens to approximate a power law fairly well. We also prove mathematical results which suggest that the power-law model is a safer tool for pace selection than the hyperbolic model and that the former more naturally models fatigue than the latter.

Dietary β-Alanine Intake Assessed by Food Records Does Not Associate With Muscle Carnosine Content in Healthy, Active, Omnivorous Men and Women.

β-Alanine (BA) is one of the most widely used sport supplements, due to its capacity to improve high-intensity exercise performance by increasing muscle carnosine (MCarn) content, and consequently, the buffering capacity of the muscle. BA is also available in a variety of animal foods, but little is currently known about the influence of dietary BA intake on MCarn. The aim of the current study was to compile a detailed summary of available data on the BA content of commonly consumed foods, and to explore whether associations could be detected between self-reported dietary BA intake and skeletal MCarn in a group of 60 healthy, active, omnivorous men and women. Dietary BA intake was assessed via 3-day food records, and MCarn content assessed by high-performance liquid chromatography. A series of univariate and multivariate linear regression models were used to explore associations between estimated dietary BA and MCarn. No evidence of associations between dietary BA intake and MCarn were identified, with effect sizes close to zero calculated from models accounting for key demographic variables (f2 ≤ 0.02 for all analyses). These findings suggest that capacity to increase MCarn via dietary strategies may be limited, and that supplementation may be required to induce increases of the magnitude required to improve performance.

Identifying the Optimal Arm Priming Exercise Intensity to Improve Maximal Leg Sprint Cycling Performance.

Priming exercises improve subsequent motor performance; however, their effectiveness may depend on the workload and involved body areas. The present study aimed to estimate the effects of leg and arm priming exercises performed at different intensities on maximal sprint cycling performance. Fourteen competitive male speed-skaters visited a lab eight times, where they underwent a body composition measurement, two V̇O2max measurements (leg and arm ergometers), and five sprint cycling sessions after different priming exercise conditions. The five priming exercise conditions included 10-minute rest (Control); 10-minute arm ergometer exercise at 20% V̇O2max (Arm 20%); 10-minute arm ergometer exercise at 70% V̇O2max (Arm 70%); 1-min maximal arm ergometer exercise at 140% V̇O2max (Arm 140%); and 10-min leg ergometer exercise at 70% V̇O2max (Leg 70%). Power outputs of 60-s maximal sprint cycling, blood lactate concentration, heart rate, muscle and skin surface temperature, and rating of perceived exertion were compared between the priming conditions at different measurement points. Our results showed that the Leg 70% was the optimal priming exercise among our experimental conditions. Priming exercise with the Arm 70% also tended to improve subsequent motor performance, while Arm 20% and Arm 140% did not. Mild elevation in blood lactate concentration by arm priming exercise may improve the performance of high-intensity exercise.

High intensity exercise performance and muscle damage. A role for free radicals

The purpose of this paper is to outline muscle damage and oxidative stress responses to high intensity exercise protocols. The information provided will be important for athletes, coaches, and the general population to provide information related to mechanisms and consequences of high intensity exercise performance

Metabolic and hormonal factors influencing high intensity exercise, recovery, and fatigue

The purpose of the paper is to consider the metabolic mechanisms contributing to high intensity exercise performance, recovery, and fatigue. A further purpose is also to consider the total stress response to exercise by outlining the catecholamine responses to exercise performance

Four Weeks of Intensified Training Enhances On-Ice Intermittent Exercise Performance and Increases Maximal Oxygen Consumption of Youth National-Team Ice Hockey Players.

We investigated whether 4 weeks of intensified training consisting of speed endurance training (SET) enhanced high-intensity exercise performance in youth national-team ice hockey players. Utilizing a randomized crossover design, we subjected 17 players to 4 weeks of SET, comprising 6 to 10 × 20 seconds at maximal effort (>95% maximum ice skating speed) with 120-second recovery performed 3 times weekly, or maintenance of regular training (control period). Before and after each period, players completed ice-hockey-specific tests on ice, including a Yo-Yo Intermittent Recovery Level 1 test, a 30-m sprint test, and an agility test. On a separate day, players were assessed for body composition with dual-energy X-ray absorptiometry and performed countermovement jump, maximal voluntary isometric knee extensor contraction, a 15-second maximal sprint test, and a submaximal and incremental test on a bike ergometer in which pulmonary oxygen consumption was determined. Yo-Yo Intermittent Recovery Level 1 test performance increased (P < .001) by 14% (95% CI, 201-496 m) during the SET period. Maximal pulmonary oxygen consumption (P < .05) and time to exhaustion (P < .05) were 4.8% and 6.5% higher, respectively, after the SET period than before. Fat-free mass increased (P < .01) during the SET period by 1.7 kg (95% CI, 1.0-2.5), whereas fat mass remained unchanged. These effects were superior to the control period. These findings underpin the effectiveness of SET for improving on-ice high-intensity performance and highlight that elite ice hockey players can benefit from implementing SET.

The effect of acute manipulation of carbohydrate availability on high intensity running performance, running economy, critical speed, and substrate metabolism in trained Male runners

ABSTRACT Completing selected training sessions with reduced glycogen availability is associated with greater signalling and improved muscle oxidative capacity, although it may impact the overall quality of the session. We examined the effects of low carbohydrate availability on high intensity exercise performance, running economy, critical speed, and substrate metabolism. On two occasions, nine male runners (V̇O2peak 60.3 ± 3.3 mL.kg−1.min−1) completed a glycogen depletion protocol involving 90-min at 75%vV̇O2peak followed by 10 × 1-min at 110% vV̇O2peak. This was followed either by high (HIGH) or low (LOW) carbohydrate intake (>6 g.kg−1.day−1 and <50 g.day−1, respectively) until completion of a performance protocol on day 2 consisting of a series of time-trials (TT) (50m to 3000m) and physiological assessments. There were no differences between LOW and HIGH for any TT distance (mean TT performance times for LOW and HIGH were: 3000m TT 651.7 ± 52.8s and 646.4 ± 52.5s, 1500 m TT 304.0 ± 20.2s and 304.2 ± 22.1s, 400 m TT 67.64 ± 4.2s and 67.3 ± 3.8s, 50 m TT 7.27 ± 0.44s and 7.25 ± 0.45s, respectively, P > 0.05), though some athletes performed better in LOW (n = 5). While fat oxidation in LOW was significantly greater than HIGH (Δ0.32 ± 0.14 g.min−1; P < 0.001 at 14 km.h−1 and Δ0.34 ± 0.12 g.min−1 at 16 km.h−1; P < 0.01), running economy did not differ between trials (P > 0.05). Acute manipulation of carbohydrate availability showed immediate effects on substrate metabolism evidenced by greater fat oxidation without changes in RE. Acute low carbohydrate availability did not affect high intensity running performance across a range of distances. Highlights Acute manipulation of muscle glycogen availability using an exercise and dietary manipulation protocol did not affect subsequent high intensity running performance across a range of running distances. Reduced muscle glycogen resulted in a marked increase in fat oxidation in low glycogen condition but no changes in running economy or critical speed. Individual factors should be considered when prescribing high intensity sessions with restricted carbohydrate availability.

Relationship between anaerobic work capacity and critical oxygenation in athletes

Objective: Anaerobic work capacity (AWC) is understood as the maximum power that the athlete can withstand over time, conditioned by high intensity effort and it is important to interpret it for the performance improvement. In addition, the muscle oxygen saturation (SmO2) provides information on muscle metabolism and hemodynamics. Likewise, critical oxygenation (CO) is the highest metabolic rate that results in a fully oxidative energy supply that reaches a stable state at the substrate level. The main problem is that SmO2 generally offers a traditional laboratory interpretation without application in field tests, Therefore, the purpose of this study is to provide the use of CO as an indicator of AWC performance in high intensity exercise. &#x0D; Methods: Twenty-two male rugby players participated. Peak torques during an isokinetic fatigue test and muscle oxygen consumption (mVO2) and SmO2 in the vastus lateralis were measured. A correlation and multiple regression analysis were applied to find an explanatory prediction model of the AWC. &#x0D; Results: A greater SmO2 amplitude and CO would mean less anaerobic work (r = -0.58 and r=-0.63) and less force production. In addition, CO along with weight (kg) can explain the AWC by 64% during high intensity exercise. &#x0D; Conclusion: The measurement of critical oxygenation is associated with the AWC, so should be considered a performance factor. These parameters could be included in NIRS sensors to evaluate muscle metabolism.

Effects Of Low Muscle Glycogen On High-intensity Exercise Performance: A Placebo-controlled Study

Muscle glycogen is the major fuel during high-intensity exercise (HIE) and large reductions can occur after relatively short durations; however, the relationship between low muscle glycogen and HIE performance has not been investigated in a placebo-controlled design. PURPOSE: To investigate the effects of low muscle glycogen content on repeated sprint ability (RSA), ratings of perceived exertion (RPE) during HIE and neuromuscular function using a double-blinded design. METHODS: Eighteen well-trained subjects (VO2max; 57 ± 5 mL·kg-1·min-1) performed glycogen-depleting cycling exercise consisting of three periods of 10x45 s at ~110% VO2max interspersed by 135 s of passive recovery between bouts and 15 min between periods. After the glycogen-depleting exercise subjects were randomly assigned to a low (LOW) or high (HIGH) carbohydrate dietary intake for 5 hours (n = 9 in each group). The diets consisted of fluid and small amounts of bars and was blinded to assessors and participants. At baseline, after each period and following the diet manipulation RSA (5x6 s sprints separated by 24 s of rest) was evaluated. Moreover, isometric knee-extensor function (maximal voluntary contractions, voluntary activation level and electrically induced low- (20 Hz) and high-frequency (50 Hz) force production) was assessed at baseline, after the exercise intervention and following the diet administration. At the same time points a 2-min fixed intensity (~90% VO2max) cycling protocol was performed with subsequent RPE measures. Finally, muscle biopsies and blood samples were obtained. RESULTS: The glycogen-depleting exercise followed by recovery in LOW and HIGH resulted in distinct glycogen concentrations (176 ± 99 vs. 292 ± 78 mmol·kg-1 dw, P < 0.01), but indifferent blood glucose concentrations (P > 0.05). This was accompanied by an impaired RSA only in LOW (7.8 ± 5.9% reduction relative to baseline, P < 0.05) coupled with a high rating of perceived exertion during HIE in LOW compared to HIGH (7.7 ± 1.2 vs. 5.6 ± 1.2 AU, P < 0.01). In contrast, no between-group difference was observed for any aspects of neuromuscular function (P > 0.05). CONCLUSIONS: Low muscle glycogen results in impaired RSA and increased RPE during HIE, whereas voluntary and electrically induced isometric knee-extensor force remains unaffected.

Effects Of Transdermal Sodium Bicarbonate Lotion On High-intensity Cycling Performance

Pre-exercise oral ingestion of sodium bicarbonate may lead to improved high-intensity exercise performance in trained individuals. However, this practice often causes gastrointestinal distress, which can mitigate the ergogenic benefits. An alternative method of administration involves the delivery of sodium bicarbonate through applying lotion to the surface of the skin surrounding the working muscles. However, few studies have examined the ergogenic benefits of this practice. PURPOSE: To examine the effects of pre-exercise application of a sodium bicarbonate lotion (SBL) on performance during a series of intermittent high-intensity cycling bouts compared to a placebo (PLA). METHODS: In a randomized cross-over fashion, 7 trained cyclists completed a one-hour cycling performance test on a stationary trainer using their personal road bikes on two separate occasions. This protocol consisted series of maximal 5-second (neuromuscular, NM), 5-minute (maximal aerobic, MAP), 20-minute (functional threshold, FTP), and 1-minute (anaerobic capacity, AC) efforts separated by recovery. Performance was determined by the mean power output during each effort. Thirty minutes prior, subjects applied 0.4 g/kg-bw of either SBL or PLA to the quadriceps, hamstrings, and gastrocnemius. Capillary samples were collected at 1-minute and 3-minutes following the MAP, FTP, and AC tests to measure blood lactate. Differences in power output and lactate responses between conditions were tested using Wilcoxon signed-rank tests. RESULTS: There were no differences in power output during the any of the efforts between conditions. In the SBL condition, participants had higher blood lactate concentrations one-minute following the MAP test compared to PLA (p = 0.01, mean dif. = 4.3 mmol/L). CONCLUSION: Our findings suggest that pre-exercise application of SBL did not influence performance in trained cyclists. The elevated blood lactate response to the MAP effort in SBL could indicate enhanced cellular buffering and lactate clearance. Practically, this suggests that SBL could be beneficial prior to shorter time-trials or intervals performed near maximal aerobic capacity. Once the target sample of 16 cyclists have completed the study, we can provide further insight on the ergogenic effects of SBL application in this population.

Ammonia Inhalants Enhance Psychophysiological Responses and Performance During Repeated High Intensity Exercise

ABSTRACTPurpose: Ammonia inhalants (NH3) are anecdotally used in competition by athletes for their purported stimulant effects. However, evidence on the efficacy of NH3 is conflicting, and little to no studies to date have investigated its effect on repeated exercise. The purpose of this study was to examine the effects of NH3 on psychophysiological responses and performance during repeated high-intensity exercise. Methods: In a counterbalanced crossover design, physically active females completed two repeated high-intensity sprint trials with a different treatment: Control (CON; water) or Ammonia Inhalants (NH3; 0.33 cc). For each trial, participants completed 3 × 15s Wingate anaerobic tests (WAnT) separated by 2 min of active recovery. Prior to each WAnT, participants took a single 3-s inhale of the corresponding treatment. After the succession of each WAnT, heart rate (HR) and rate of perceived exertion (RPE) were documented. Subjective feelings of alertness and “psyched up” energy were measured using a visual analog scale. Trials were separated by at least 48 hr. Results: The results indicate that over the WAnTs, mean power (p = .017) and peak power (p = .006) were significantly higher with NH3 compared to CON despite a lack of changes in fatigue index (p = .928). HR (p = .101) and RPE (p = .897) were not different with varying treatments. Perceived alertness (p = .010) and psyched-up energy (p = .002) were significantly higher with NH3 versus CON. Conclusion: These findings provide empirical support for the use of NH3 to improve repeated high-intensity exercise performance in females that may be underpinned by alterations in subjective alertness and energy.

Effects of serial and acute enteric-coated sodium bicarbonate supplementation on anaerobic performance, physiological profile, and metabolomics in healthy young men.

BackgroundPrevious studies have reported that sodium bicarbonate ingestion may enhance high-intensity exercise performance and cause severe gastrointestinal distress. However, enteric-coated sodium bicarbonate may reduce gastrointestinal symptoms of sodium bicarbonate after oral administration. This remains to be confirmed. This study aimed to verify the effects of serial and acute enteric-coated sodium bicarbonate supplementation on anaerobic performance, physiological profile, and metabolomics in healthy young men.MethodsHealthy young males (n = 12) ingested 0.2 g/kg body mass of enteric-coated sodium bicarbonate (ES) in serial enteric-coated sodium bicarbonate (SES, continuous ES supplementation for 5 days) and acute enteric-coated sodium bicarbonate (AES, acute ES supplementation before exercise) or a placebo (PL) in a randomized crossover design. After each supplement protocol, the participants completed four Wingate anaerobic tests (WAT). The first three Wingate tests (testing anaerobic capacity) were performed with a 5-min passive recovery between each. After the third Wingate test, participants were required to complete a 50-min recovery followed by a fourth WAT test (testing the recovery of anaerobic capacity after 50-min intervals). Blood lactate (BLA), heart rate (HR), and ratings of perceived exertion (RPE) were measured in all conditions during the test, as was the subjective gastrointestinal–symptoms assessment questionnaire (GSAQ). Mean power (MP) and peak power (PP) were recorded after four WATs. Urine samples were collected before the test and 50 min after the 3rd WAT.ResultsSerial enteric-coated sodium bicarbonate supplementation improved anaerobic capacity in the third bout of WATs, as observed based on an increase in mean power (SES vs. PL (613 ± 57 vs. 542 ± 64 W), P = 0.024) and peak power (SES vs. PL (1,071 ± 149 vs. 905 ± 150 W), P = 0.016). Acute ES supplementation did not affect anaerobic capacity. The occurrence of gastrointestinal symptoms after enteric-coated sodium bicarbonate supplementation was minimal and no difference compared to placebo in the current study. In particular, serial enteric-coated sodium bicarbonate supplementation had no gastrointestinal side effects before the test. The AES and SES groups had a trivial effect on blood lactate compared to the PLA group. There was no significant difference in HR and RPE among the three groups. Based on targeted metabolomics analysis, the 50 min after the third WAT, the levels of lactate (P < 0.001), L-Malic acid (P < 0.05), and oxaloacetate (P < 0.05) were significantly higher in the SES group than in the PL group. Compared with the AES group, the levels of lactate and fumarate in the SES group were significantly increased (P < 0.05).ConclusionsOur study indicates that serial enteric-coated sodium bicarbonate supplementation positively improves anaerobic performance among healthy young men. However, acute ingestion of enteric-coated sodium bicarbonate did not improve anaerobic exercise performance. Either with serial or acute supplementation doses, enteric-coated sodium bicarbonate produced fewer gastrointestinal symptoms and no difference compared to placebo, especially with no gastrointestinal side effects after serial supplementation. Serial and acute supplementation of enteric-coated sodium bicarbonate might tend to promote lactate clearance. Furthermore, serial enteric-coated sodium bicarbonate ingestion may cause changes in the metabolism of lactate, L-Malic acid, oxaloacetate, and fumarate 50 min after exercise, which presumably may promote the tricarboxylic acid cycle and lactate clearance.

The effects of inspiratory muscle fatigue on subsequent high-intensity exercise performance and muscle tissue oxygenation

The effects of inspiratory muscle fatigue on subsequent high-intensity exercise performance and muscle tissue oxygenation

The Impact of Pre-Exercise Carbohydrate Meal on the Effects of Yerba Mate Drink on Metabolism, Performance, and Antioxidant Status in Trained Male Cyclists

IntroductionThe consumption of yerba mate (YM), a source of antioxidants, in a fasted state increases fatty acid oxidation (FATox) during low–moderate-intensity exercise and improves performance in high-intensity exercise. However, the impact of a pre-exercise carbohydrate (CHO) meal on YM effects during exercise is unknown.ObjectiveWe investigated the effects of yerba mate drink (YMD) consumed in the fasted state (YMD-F) or after a CHO meal (YMD-CHO) on measurements of metabolism, performance, and blood oxidative stress markers in cycling exercise.MethodsIn a randomized, repeated-measures, crossover design, eight trained male cyclists ingested (i) YMD-CHO, (ii) YMD-F, or (iii) control-water and CHO meal (Control-CHO). The YMD (an infusion of 5 g of ultrarefined leaves in 250 mL of water) was taken for 7 days and 40 min before exercise. CHO meal (1 g/kg body mass) was consumed 60 min before exercise. The cycling protocol included a 40-min low-intensity (~ 53% V̇O2peak) constant load test (CLT); a 20-min time trial (TT); and 4 × 10-s all-out sprints. Blood samples and respiratory gases were collected before, during, and/or after tests.ResultsDuring CLT, YMD-CHO increased FATox ~ 13% vs. YMD-F (P = 0.041) and ~ 27% vs. Control-CHO (P < 0.001). During TT, YMD-CHO increased FATox ~ 160% vs. YMD-F (P < 0.001) and ~ 150% vs. Control-CHO (P < 0.001). Power output during TT improved ~ 3% (P = 0.022) in YMD-CHO vs. Control-CHO and was strongly correlated with changes in serum total antioxidant capacity (r = −0.87) and oxidative stress index (r = 0.76) at post-exercise in YMD-CHO. Performance in sprints was not affected by YMD.ConclusionCHO intake did not negate the effect of YMD on FATox or TT performance. Instead, a synergism between the two dietary strategies may be present.Clinical Trial Registration NCT04642144. November 18, 2020. Retrospectively registered.

High-Intensity Interval Exercise Performance in Judo Athletes: Physiological, Perceptual, and Pacing Responses.

This study aimed to verify the behavior of physiological, perceptual, and performance responses during a high-intensity exercise in judo athletes and to identify if this protocol is able to discriminate athletes from different levels (national vs. state). Forty-five male judo athletes participated and were divided into two groups: state (age 24.2 ± 3.7years) and national (22.1 ± 3.3years). Judo athletes performed a judo-specific protocol contained high-intensity intermittent exercise consisted of 12 sets of 20s in all-out intensity. During the protocol, the repetitions and heart rate were assessed over the sets, and at the end of the protocol, the rate of perceived exertion was measured. The results showed that the national group presented higher repetitions (29 ± 4 repetitions) during the high-intensity intermittent exercise compared with state (22 ± 2 repetitions). However, the national group showed a progressive decrease of repetitions up to the middle of the protocol, which coincided with higher values of heart rate compared with state (first and second sets). There was a decrease of repetitions from the first set (p < .001) and similar values of heart rate from the third set in the state. In conclusion, the performance (in repetitions) during the high-intensity intermittent exercise was able to discriminate athletes from different competitive levels. National athletes presented better performance, but worse pacing strategy compared with state.