The Effect of Caffeine on Repeat-High-Intensity-Effort Performance in Rugby League Players

2017 ◽  
Vol 12 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Brandon M. Wellington ◽  
Michael D. Leveritt ◽  
Vincent G. Kelly
Keyword(s):  
Blood Lactate ◽  
High Intensity ◽  
Perceived Exertion ◽  
Rugby League ◽  
Rating Of Perceived Exertion ◽  
Critical Periods ◽  
Placebo Condition ◽  
Double Blind ◽  
Significant Difference ◽  
Experimental Trials

Context:Repeat-high-intensity efforts (RHIEs) have recently been shown to occur at critical periods of rugby league matches.Purpose:To examine the effect that caffeine has on RHIE performance in rugby league players.Methods:Using a double-blind, placebo-controlled, crossover design, 11 semiprofessional rugby league players (age 19.0 ± 0.5 y, body mass 87.4 ± 12.9 kg, height 178.9 ± 2.6 cm) completed 2 experimental trials that involved completing an RHIE test after either caffeine (300 mg caffeine) or placebo (vitamin H) ingestion. Each trial consisted of 3 sets of 20-m sprints interspersed with bouts of tackling. During the RHIE test, 20-m-sprint time, heart rate (HR), rating of perceived exertion (RPE), and blood lactate were measured.Results:Total time to complete the nine 20-m sprints during the caffeine condition was 1.0% faster (28.46 ± 1.4 s) than during the placebo condition (28.77 ± 1.7 s) (ES = 0.18, 90%CI –0.7 to 0.1 s). This resulted in a very likely chance of caffeine being of benefit to RHIE performance (99% likely to be beneficial). These improvements were more pronounced in the early stages of the test, with a 1.3%, 1.0%, and 0.9% improvement in sprint performance during sets 1, 2, and 3 respectively. There was no significant difference in RPE across the 3 sets (P = .47, 0.48, 1.00) or mean HR (P = .36), maximal HR (P = .74), or blood lactate (P = .50) between treatment conditions.Conclusions:Preexercise ingestion of 300 mg caffeine produced practically meaningful improvements in RHIE performance in rugby league players.

scholarly journals Impact of Sodium Bicarbonate on Blood Lactate and Psychometric Dimensions of Fatigue

2021 ◽  
Author(s):  
Heather E. Webb ◽  
Christopher Garrett ◽  
Mikaela D. Boham
Keyword(s):  
Body Weight ◽  
Sodium Bicarbonate ◽  
Blood Lactate ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Double Blind ◽  
Significant Difference ◽  
Response To Exercise ◽  
The Impact ◽  
Blind Manner

Abstract Background The purpose of this study was to assess the impact of sodium bicarbonate (NaHCO3) on blood lactate (BLa) and psychometric dimensions of fatigue in response to exercise. Methods Twelve recreationally active subjects (age 22.25 ± 2.70 years) performed three (one control and two supplemented) sessions of a 20-minute progressive exercise routine. Subjects completed the control condition during session one, and in the two subsequent sessions, subjects were randomly provided a beverage with either a 0.15g•kg− 1 body weight NaHCO3 or a placebo of 0.30g•kg− 1 body weight calcium carbonate (CaCO3) in a double-blind manner. Measurements of BLa, heart rate (HR), state anxiety (SAI), rating of perceived exertion (RPE), and perceived mood states (POMS) were measured prior to and during the exercise protocol, and then immediately post-exercise. Results BLa levels were significantly different [F(8,88) = 2.04, p < .05] between the three conditions. Further, BLa [F(4,44) = 41.25, p < .05], HR [F(4,32) = 182.16, p < .05], and RPE [F(4,44) = 140.13, p < .05] increased significantly as exercise progressed, with BLa [F(2,22) = 5.55, p < .05 ] and RPE [F(2,22) = 4.09, p < .05] changing differently between conditions. SAI responses showed no change from to pre-to post-measures, but a significant difference was seen between the conditions [F(2, 22) = 3.84, p = .05], with differences between the placebo and NaHCO3, but not the control. Only the POMS subscale of vigor was different between conditions [F(2, 22) = 7.69, p = .003], while the subscales of tension [F(1, 11) = 6.59, p = .03], anger [F(1, 11) = 9.81, p = .01], and confusion [F(1, 11) = 7.21, p = .02] changed across time. Conclusions Both BLa and RPE were greatest in the control condition compared to the placebo and NaHCO3 conditions, with no differences being seen between the control and NaHCO3 conditions for RPE, and between the placebo and NaHCO3 conditions for BLa. Using either NaHCO3 or CaCO3 appears to provide benefits by blunting BLa production during progressively intensive exercise, but differences in psychometric values suggest that other psychophysiological factors may impact perceptions of effort.

scholarly journals Effects of Beetroot Juice Supplementation on Cognitive Function, Aerobic and Anaerobic Performances of Trained Male Taekwondo Athletes: A Pilot Study

2021 ◽  
Vol 18 (19) ◽  
pp. 10202
Author(s):  
Hossein Miraftabi ◽  
Zahra Avazpoor ◽  
Erfan Berjisian ◽  
Amir Sarshin ◽  
Sajjad Rezaei ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Blood Lactate ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Rating Of Perceived Exertion ◽  
Beetroot Juice ◽  
Double Blind ◽  
Specific Performance ◽  
Before And After ◽  
Experimental Trials

Studies have shown that nitrate (NO3−)-rich beetroot juice (BJ) supplementation improves endurance and high-intensity intermittent exercise. The dose–response effects on taekwondo following BJ supplementation are yet to be determined. This study aimed to investigate two acute doses of 400 mg of NO3− (BJ-400) and 800 mg of NO3− (BJ-800) on taekwondo-specific performance and cognitive function tests compared with a placebo (PL) and control (CON) conditions. Eight trained male taekwondo athletes (age: 20 ± 4 years, height: 180 ± 2 cm, body mass: 64.8 ± 4.0 kg) completed four experimental trials using a randomized, double-blind placebo-controlled design: BJ-400, BJ-800, PL, and CON. Participants consumed two doses of BJ-400 and BJ-800 or nitrate-depleted PL at 2.5 h prior to performing the Multiple Frequency Speed of Kick Test (FSKT). Countermovement jump (CMJ) was performed before the (FSKT) and PSTT, whereas cognitive function was assessed (via the Stroop test) before and after supplementation and 10 min following PSTT. Blood lactate was collected before the CMJ tests immediately and 3 min after the FSKT and PSST; rating of perceived exertion (RPE) was recorded during and after both specific taekwondo tests. No significant differences (p > 0.05), with moderate and large effect sizes, between conditions were observed for PSTT and FSKT performances. In addition, blood lactate, RPE, heart rate, and CMJ height were not significantly different among conditions (p > 0.05). However, after the PSTT test, cognitive function was higher in BJ-400 compared to other treatments (p < 0.05). It was concluded that acute intake of 400 and 800 mg of NO3−rich BJ reported a moderate to large effect size in anaerobic and aerobic; however, no statistical differences were found in taekwondo-specific performance.

scholarly journals Acute Caffeine Ingestion did not Enhance Punch Performance in Professional Mixed-Martial Arts Athletes

Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1422 ◽  
Author(s):  
Arthur de Azevedo ◽  
Mauro Guerra ◽  
Leonardo Caldas ◽  
Lucas Guimarães-Ferreira
Keyword(s):  
Martial Arts ◽  
Perceived Exertion ◽  
Force Transducer ◽  
Rating Of Perceived Exertion ◽  
Combat Sport ◽  
Mixed Martial Arts ◽  
Placebo Condition ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Punch Force

Mixed martial arts (MMA) is a combat sport where competitors utilize strikes (punches, kicks, knees, and elbows) and submission techniques to defeat opponents in a cage or ring. The aim of this study was to investigate the effect of acute caffeine ingestion on punching performance by professional MMA athletes. The study used a double-blind, counterbalanced, crossover design. Eleven professional MMA competitors (27.6 ± 4.3 years and 83.5 ± 7.8 kg of body weight) ingested a dose of caffeine (5 mg·kg−1) or placebo 60 min prior to three sets of punching. Each set consisted of 15 s, at which participants were asked to perform straight punches with maximum strength and frequency with his dominant arm. After each set, a 45 s recovery time was applied. Using a force transducer attached to a cushioned plate, the punch frequency, and mean and maximal punch force was measured. The readiness to invest in both physical (RTIPE) and mental (RTIME) effort was assessed prior to the protocol, and the rating of perceived exertion (RPE) was recorded after. Caffeine ingestion did not result in increased punching frequency, mean and maximum punch force, RTIPE, RTIME, and RPE when compared to the placebo condition. Based on these results, acute caffeine ingestion did not improve punching performance in professional MMA athletes.

Failure of Glycine-Arginine-α-Ketoisocaproic Acid to Improve High-Intensity Exercise Performance in Trained Cyclists

2011 ◽  
Vol 21 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Lukas Beis ◽  
Yaser Mohammad ◽  
Chris Easton ◽  
Yannis P. Pitsiladis
Keyword(s):  
Exercise Performance ◽  
High Intensity ◽  
Perceived Exertion ◽  
Cycle Ergometer ◽  
High Intensity Exercise ◽  
Ratings Of Perceived Exertion ◽  
Mean Power ◽  
Double Blind ◽  
Oral Supplementation ◽  
Experimental Trials

Oral supplementation with glycine-arginine-α-ketoisocaproic acid (GAKIC) has previously been shown to improve exhaustive high-intensity exercise performance. There are no controlled studies involving GAKIC supplementation in well-trained subjects. The aim of the current study was to examine the effects of GAKIC supplementation on fatigue during high-intensity, repeated cycle sprints in trained cyclists. After at least 2 familiarization trials, 10 well-trained male cyclists completed 2 supramaximal sprint tests each involving 10 sprints of 10 s separated by 50-s rest intervals on an electrically braked cycle ergometer. Subjects ingested 11.2 g of GAKIC or placebo (Pl) during a period of 45 min before the 2 experimental trials, administered in a randomized and double-blind fashion. Peak power declined from the 1st sprint (M ± SD; Pl 1,332 ± 307 W, GAKIC 1,367 ± 342 W) to the 10th sprint (Pl 1,091 ± 229 W, GAKIC 1,061 ± 272 W) and did not differ between conditions (p = .88). Mean power declined from the 1st sprint (Pl 892 ± 151 W, GAKIC 892 ± 153 W) to the 10th sprint (Pl 766 ± 120 W, GAKIC 752 ± 138 W) and did not differ between conditions (p = .96). The fatigue index remained at ~38% throughout the series of sprints and did not differ between conditions (p = .99). Heart rate and ratings of perceived exertion increased from the 1st sprint to the 10th sprint and did not differ between conditions (p = .11 and p = .83, respectively). In contrast to previous studies in untrained individuals, these results suggest that GAKIC has no ergogenic effect on repeated bouts of high-intensity exercise in trained individuals.

scholarly journals The Dose-Effects of Caffeine on Lower Body Maximal Strength, Muscular Endurance, and Rating of Perceived Exertion in Strength-Trained Females

Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3342
Author(s):  
Louise Jones ◽  
Iona Johnstone ◽  
Charlotte Day ◽  
Sasha Le Marquer ◽  
Andrew T. Hulton
Keyword(s):  
Effect Size ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Hormonal Contraception ◽  
Rating Of Perceived Exertion ◽  
Muscular Endurance ◽  
Lower Body ◽  
Double Blind ◽  
Strength Performance ◽  
Significant Difference

Caffeine supplementation has shown to be an effective ergogenic aid enhancing athletic performance, although limited research within female populations exists. Therefore, the aim of the investigation was to assess the effect of pre-exercise caffeine supplementation on strength performance and muscular endurance in strength-trained females. In a double-blind, randomised, counterbalanced design, fourteen strength-trained females using hormonal contraception consumed either 3 or 6 mg·kg−1 BM of caffeine or placebo (PLA). Following supplementation, participants performed a one-repetition maximum (1RM) leg press and repetitions to failure (RF) at 60% of their 1RM. During the RF test, rating of perceived exertion (RPE) was recorded every five repetitions and total volume (TV) lifted was calculated. Repeated measures ANOVA revealed that RF (p = 0.010) and TV (p = 0.012) attained significance, with pairwise comparisons indicating a significant difference between 3 mg·kg−1 BM and placebo for RF (p = 0.014), with an effect size of 0.56, and for 6 mg·kg−1 BM (p = 0.036) compared to the placebo, with an effect size of 0.65. No further significance was observed for 1RM or for RPE, and no difference was observed between caffeine trials. Although no impact on lower body muscular strength was observed, doses of 3 and 6 mg·kg−1 BM of caffeine improved lower body muscular endurance in resistance-trained females, which may have a practical application for enhancing resistance training stimuli and improving competitive performance.

scholarly journals Effects of Half-Time Cooling Using a Fan with Skin Wetting on Thermal Response During Intermittent Cycling Exercise in the Heat

2021 ◽  
Vol 05 (03) ◽  
pp. E91-E98
Author(s):  
Jumpei Osakabe ◽  
Masanobu Kajiki ◽  
Kiho Kondo ◽  
Takaaki Matsumoto ◽  
Yoshihisa Umemura
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Rating Of Perceived Exertion ◽  
Half Time ◽  
Physiological Strain ◽  
Cycling Exercise ◽  
Repeated Sprint ◽  
Significant Difference ◽  
Sprint Cycling ◽  
Experimental Trials

AbstractThe present study investigated the effects of half-time (HT) break cooling using a fan and damp sponge on physiological and perceptual responses during the 2nd half of a repeated-sprint exercise in a hot environment. Eight physically active men performed a familiarization trial and two experimental trials of a 2×30-min intermittent cycling exercise protocol with a 15-min HT break in hot conditions (35°C, 50% relative humidity). Two experimental trials were conducted in random order: skin wetting with a fan (FANwet) and no cooling (CON). During the 2nd half, a repeated-sprint cycling exercise was performed: i. e., 5 s of maximal pedaling (body weight×0.075 kp) every minute, separated by 25 s of unloaded pedaling (80 rpm) and 30 s of rest. Rectal temperature, skin temperature (chest, forearm, thigh, and calf), heart rate, physiological strain index, rating of perceived exertion, thermal sensation, and comfort were significantly improved in the FANwet condition (P<0.05). There was no significant difference in the repeated-sprint cycling exercise performance between conditions. The results suggest that skin wetting with a fan during the HT break is a practical and effective cooling strategy for mitigating physiological and perceptual strain during the 2nd half in hot conditions.

Caffeinated Chewing Gum Improves Bicycle Motocross Time-Trial Performance

2020 ◽  
Vol 30 (6) ◽  
pp. 427-434 ◽  
Author(s):  
Amin Daneshfar ◽  
Carl J. Petersen ◽  
Majid S. Koozehchian ◽  
Daniel E. Gahreman
Keyword(s):  
Perceived Exertion ◽  
Weight Ratio ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Repeated Measure ◽  
Chewing Gum ◽  
Placebo Condition ◽  
Double Blind ◽  
Measure Analysis ◽  
Repeated Measure Analysis

This study aimed to identify the acute effects of caffeinated chewing gum (CAF) on bicycle motocross (BMX) time-trial (TT) performance. In a randomized, placebo-controlled, double-blind cross-over design, 14 male BMX riders (age = 20.0 ± 3.3 years; height = 1.78 ± 0.04 m; body mass = 72 ± 4 kg), consumed either (300 mg; 4.2 ± 0.2 mg/kg) caffeinated (300 mg caffeine, 6 g sugars) or a placebo (0 mg caffeine, 0 g sugars) gum, and undertook three BMX TTs. Repeated-measure analysis revealed that CAF has a large ergogenic effect on TT time, F(1, 14) = 33.570, p = .001, ; −1.5% ± 0.4 compared with the placebo. Peak power and maximal power to weight ratio also increased significantly compared with the placebo condition, F(1, 14) = 54.666, p = .001, ; +3.5% ± 0.6, and F(1, 14) = 57.399, p = .001, ; +3% ± 0.3, respectively. Rating of perceived exertion was significantly lower F(1, 14) = 25.020, p = .001, in CAF (6.6 ± 1.3) compared with the placebo (7.2 ± 1.7). Administering a moderate dose (300 mg) of CAF could improve TT time by enhancing power and reducing the perception of exertion. BMX coaches and riders may consider consuming CAF before a BMX race to improve performance and reduce rating of perceived exertion.

Anaerobic Threshold Prediction Using the OMNI-Walk/Run Scale in Long-Distance Runners: A Preliminary Study

2021 ◽  
Vol 16 (5) ◽  
pp. 727-730
Author(s):  
Yuri de Almeida Costa Campos ◽  
Jeferson M. Vianna ◽  
Miller P. Guimarães ◽  
Hiago L.R. Souza ◽  
Raúl Domínguez ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Anaerobic Threshold ◽  
Lactate Threshold ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Distance Runners ◽  
Long Distance ◽  
Incremental Test ◽  
Significant Difference

Purpose: To identify the anaerobic threshold through the lactate threshold determined by Dmax and rating of perceived exertion (RPE) threshold by Dmax and to evaluate the agreement and correlation between lactate threshold determined by Dmax and RPE threshold by Dmax during an incremental test performed on the treadmill in long-distance runners. Methods: A total of 16 long-distance runners volunteered to participate in the study. Participants performed 2 treadmill incremental tests for the collection of blood lactate concentrations and RPE separated by a 48-hour interval. The incremental test started at 8 km·h−1, increasing by 1.2 km·h−1 every third minute until exhaustion. During each stage of the incremental test, there were pauses of 30 seconds for the collection of blood lactate concentration and RPE. Results: No significant difference was found between methods lactate threshold determined by Dmax and RPE threshold by Dmax methods (P = .664). In addition, a strong correlation (r = .91) and agreement through Bland–Altman plot analysis were found. Conclusions: The study demonstrated that it is possible to predict anaerobic threshold from the OMNI-walk/run scale curve through a single incremental test on the treadmill. However, further studies are needed to evaluate the reproducibility and objectivity of the OMNI-walk/run scale for anaerobic threshold determination.

scholarly journals Expectancy of ergogenicity from sodium bicarbonate ingestion increases high-intensity cycling capacity

2016 ◽  
Vol 41 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Matthew F. Higgins ◽  
Akbar Shabir
Keyword(s):  
Sodium Bicarbonate ◽  
High Intensity ◽  
Perceived Exertion ◽  
Metabolic Flux ◽  
Tap Water ◽  
Nutritional Supplement ◽  
Peak Power Output ◽  
Double Blind ◽  
Gut Fullness ◽  
Experimental Trials

This study examined whether expectancy of ergogenicity of a commonly used nutritional supplement (sodium bicarbonate; NaHCO3) influenced subsequent high-intensity cycling capacity. Eight recreationally active males (age, 21 ± 1 years; body mass, 75 ± 8 kg; height, 178 ± 4 cm; WPEAK = 205 ± 22 W) performed a graded incremental test to assess peak power output (WPEAK), one familiarisation trial and two experimental trials. Experimental trials consisted of cycling at 100% WPEAK to volitional exhaustion (TLIM) 60 min after ingesting either a placebo (PLA: 0.1 g·kg−1 sodium chloride (NaCl), 4 mL·kg−1 tap water, and 1 mL·kg−1 squash) or a sham placebo (SHAM: 0.1 g·kg−1 NaCl, 4 mL·kg−1 carbonated water, and 1 mL·kg−1 squash). SHAM aimed to replicate the previously reported symptoms of gut fullness (GF) and abdominal discomfort (AD) associated with NaHCO3 ingestion. Treatments were administered double blind and accompanied by written scripts designed to remain neutral (PLA) or induce expectancy of ergogenicity (SHAM). After SHAM mean TLIM increased by 9.5% compared to PLA (461 ± 148 s versus 421 ± 150 s; P = 0.048, d = 0.3). Ratings of GF and AD were mild but ∼1 unit higher post-ingestion for SHAM. After 3 min TLIM overall ratings of perceived exertion were 1.4 ± 1.3 units lower for SHAM compared to PLA (P = 0.020, d = 0.6). There were no differences between treatments for blood lactate, blood glucose, or heart rate. In summary, ergogenicity after NaHCO3 ingestion may be influenced by expectancy, which mediates perception of effort during subsequent exercise. The observed ergogenicity with SHAM did not affect our measures of cardiorespiratory physiology or metabolic flux.

scholarly journals Dose Response of a Novel Exogenous Ketone Supplement on Physiological, Perceptual and Performance Parameters

2020 ◽  
Author(s):  
Philip J. Prins ◽  
Dominic P. D’Agostino ◽  
Christopher Q. Rogers ◽  
Dana L. Ault ◽  
Gary L. Welton ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Blood Lactate ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Ketone Bodies ◽  
Rating Of Perceived Exertion ◽  
Gaseous Exchange ◽  
Double Blind ◽  
Post Exercise ◽  
And Performance

Abstract Background: Interest into the health, disease, and performance impact of exogenous ketone bodies has rapidly expanded due to their multifaceted physiological and signaling properties but limiting our understanding is the isolated analyses of individual types and dose/dosing protocols. Methods: Thirteen recreational male distance runners (24.8±9.6y, 72.5±8.3kg, VO2max 60.1±5.4ml/kg/min) participated in this randomized, double-blind, crossover design study. The first two sessions consisted of a 5-km running time trial (TT) familiarization and a VO2max test. During subsequent trials, subjects were randomly assigned to one (KS1:22.1g) or two (KS2:44.2g) doses of beta-hydroxybutyrate (βHB) and medium chain triglycerides (MCTs) or flavor matched placebo (PLA). Blood R-βHB, glucose, and lactate concentrations were measured at baseline (0-min), post-supplement (30 & 60mins), post-exercise (+0min, +15mins). Time, heart rate (HR), rating of perceived exertion (RPE), affect, respiratory exchange ratio (RER), oxygen consumption (VO2), carbon dioxide production (VCO2), and ventilation (VE) were measured during exercise. Cognitive performance was evaluated prior to and post-exercise. Results: KS significantly increased R-βHB, with more potent and prolonged elevations in KS2, illustrating an administrative and dosing effect. R-βHB was significantly decreased in KS1 compared to KS2 illustrating a dosing and exercise interaction effect. Blood glucose elevated post-exercise but was unchanged across groups. Blood lactate significantly increased post-exercise but was augmented by KS administration. Gaseous exchange, respiration, HR , affect, RPE, and exercise performance was unaltered with KS administration. However, clear responders and none-responders were indicated. KS2 significantly augmented cognitive function in pre-exercise conditions, while exercise increased cognitive performance for KS1 and PLA to pre-exercise KS2 levels. Conclusion: Novel βHB+MCT formulation had a dosing effect on R-βHB and cognitive performance, an administrative response on blood lactate, while not influencing gaseous exchange, respiration, HR, affect, RPE, and exercise performance.

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