scholarly journals Effects of Caffeine Supplementation on Power Performance in a Flywheel Device: A Randomised, Double-Blind Cross-Over Study

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 255 ◽  
Author(s):  
Daniel Castillo ◽  
Raúl Domínguez ◽  
Alejandro Rodríguez-Fernández ◽  
Javier Raya-González
Keyword(s):  
Inertial Load ◽  
Power Performance ◽  
Mean Power ◽  
Placebo Condition ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Squat Exercise ◽  
Ergogenic Effects ◽  
The Mean ◽  
Double Blind Design

Despite the demonstrated evidence of the importance of eccentric contractions in sports performance, no research has evaluated the ergogenic effects of caffeine on this type of contraction means during flywheel exercises. Therefore, the aims of the present study were to compare the power outcomes, using different inertial loads, between caffeine and placebo conditions. Twenty-four young, healthy, and active men (age: 22.5 ± 4.8 years) took part in the study. A crossed, randomised double-blind design was used to analyse the effects of caffeine on lower limb power outcomes during a flywheel half-squat exercise. Participants completed four sets of eight all-out repetitions with a fixed three-minutes rest interval, and each set was performed using different inertial loads (i.e., 0.025, 0.050, 0.075 and 0.100 kg·m−2). Both the mean power (MP) and peak power (PP) in concentric (CON) and eccentric (ECC) movement phases at each inertial load were recorded after participants were administered either a caffeine supplement (6 mg·kg−1) or placebo (sucrose). Participants receiving a caffeine supplementation demonstrated improvements versus the placebo in total MP (MPtotal), as well as MP in CON phase (MPcon) and in ECC phase (MPecc) at each inertial load (22.68 to 26.53%; p < 0.01, effect size (ES) = 0.89–1.40). In addition, greater improvements with caffeine ingestion were obtained with respect to the placebo condition (18.79 to 24.98%; p < 0.01, ES = 1.03–1.40) in total PP (PPtotal), as well as PP in CON phase (PPcon) and in ECC phase (PPecc) at each inertial load. Thus, the supplementation of 6 mg·kg−1 caffeine may be considered to maximise on-field physical performance in those sports characterised by high demands of resistance.

Caffeine, but not bicarbonate, improves 6 min maximal performance in elite rowers

2014 ◽  
Vol 39 (9) ◽  
pp. 1058-1063 ◽  
Author(s):  
Peter M. Christensen ◽  
Mads H. Petersen ◽  
Signe N. Friis ◽  
Jens Bangsbo
Keyword(s):  
Sodium Bicarbonate ◽  
Perceived Exertion ◽  
Performance Test ◽  
Light Weight ◽  
Mean Power ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Maximal Performance ◽  
Ergogenic Effects ◽  
Elite Rowers

This study examined the ergogenic effects in a 6 min maximal performance test (PT) on 12 elite rowers: 6 open-weight (mean ± SD; 25 ± 1 years, and 92 ± 3 kg) and 6 light-weight (25 ± 3 years, and 73 ± 6 kg), following supplementation with caffeine (CAF), sodium bicarbonate (SB), and the combination of both, in a double-blind randomized placebo (PLA) controlled design. PT was executed on 4 occasions, on separate days within a week, and in a non-fasted state, with standardized training being performed the day before PT. Protocols were as follows: (i) CAF, 3 mg/kg, 45 min prior to PT + calcium as SB-PLA; (ii) SB, 0.3 g/kg, 75 min prior to PT + dextrose as CAF-PLA; (iii) CAF + SB; and (iv) PLA; CAF-PLA + SB-PLA. The total distance in the CAF (1878 ± 97 m) and CAF + SB (1877 ± 97 m) was longer than in the PLA (1865 ± 104 m; P < 0.05) and SB (1860 ± 96 m; P < 0.01). The mean power in CAF (400 ± 58 W) and CAF + SB (400 ± 58 W) was higher than the PLA (393 ± 61 W; P < 0.05) and SB (389 ± 57 W; P < 0.01). In CAF and CAF + SB, power was higher (P < 0.05) relative to PLA in the last half (4–6 min) of PT. Trials with CAF were more effective in light-weight rowers (1.0% ± 0.8% improvement in distance; P < 0.05) than in open-weight rowers (0.3% ± 0.8%; P > 0.05). No difference between interventions was observed for readiness and stomach comfort before PT and perceived exertion during PT. This study demonstrates that caffeine ingestion does improve performance in elite rowing. In contrast sodium bicarbonate does not appear to be ergogenic, but it does not abolish the ergogenic effect of caffeine.

scholarly journals Effects Of Caffeine, Beetroot Juice And Its Interaction Consumption On Exercise-Related Fatigue

Kinesiology ◽  
2021 ◽  
Vol 53 (2) ◽  
pp. 185-192
Author(s):  
Daniel Castillo ◽  
Alejandro Rodríguez-Fernández ◽  
Rodrigo Ramirez-Campillo ◽  
Javier Raya-González
Keyword(s):  
Beetroot Juice ◽  
Mean Power ◽  
Experimental Conditions ◽  
Placebo Condition ◽  
Double Blind ◽  
Performance Reduction ◽  
Significant Performance ◽  
And Performance ◽  
Double Blind Design ◽  
Mean Power Output

The aim of this study was to analyze the effect of different supplementation conditions on fatigue and performance in flywheel half-squat tests in senior men. Sixteen active males (age: 22.8±4.9 years; body mass index: 23.7±2.4 kgm-2) participated in the intervention during a 4-week period. Four experimental conditions were established using a double-blind design: placebo, caffeine (CAF), beetroot juice (BRJ), and combined BRJ+CAF. To assess the effect of supplementation, participants completed a countermovement jump (CMJ) before (Pre), 30 s after (Post-30s) and 180 s after (Post-180 s) completing a flywheel half-squat exercise protocol (four sets of eight all-out repetitions, with 3-min inter-set rest, using different inertial loads). Additionally, the mean power output during the flywheel half-squat protocol was recorded. Repeated measured ANOVA showed greater mean power (~1000 W, p&lt;.001) produced/OR/generated in flywheel exercise after the CAF, BRJ and BRJ+CAF consumption compared to the placebo condition. After placebo, CAF and BRJ, CMJ performance at Post-180 s was reduced compared to Pre (p=.003-.087, two-way ANOVA; ES=-0.39/-0.49), although no significant performance reduction (p=.087) was noted after BRJ+CAF. In conclusion, compared to placebo, CAF, BRJ and BRJ+CAF allow greater total mean power in the flywheel half-squat power test, although without effects on exercise-related fatigue. Additionally, BRJ+CAF improved recovery after a high demanding power-production protocol.

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.

scholarly journals Challenging the Myth of Non-Response to the Ergogenic Effects of Caffeine Ingestion on Exercise Performance

Nutrients ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 732 ◽  
Author(s):  
Juan Del Coso ◽  
Beatriz Lara ◽  
Carlos Ruiz-Moreno ◽  
Juan Salinero
Keyword(s):  
Physical Performance ◽  
Ergogenic Effect ◽  
Caffeine Intake ◽  
Correct Identification ◽  
Repeated Testing ◽  
Mean Power ◽  
Caffeine Ingestion ◽  
Cycling Test ◽  
Ergogenic Effects ◽  
The Individual

The ergogenicity of caffeine on several exercise and sport situations is well-established. However, the extent of the ergogenic response to acute caffeine ingestion might greatly vary among individuals despite using the same dosage and timing. The existence of one or several individuals that obtained minimal ergogenic effects or even slightly ergolytic effects after caffeine intake (i.e., non-responders) has been reported in several previous investigations. Nevertheless, the concept non-responding to caffeine, in terms of physical performance, relies on investigations based on the measurement of one performance variable obtained once. Recently it has been suggested that correct identification of the individual ergogenic effect induced by caffeine intake requires the repeated measurement of physical performance in identical caffeine–placebo comparisons. In this communication, we present data from an investigation where the ergogenic effect of acute caffeine intake (3 mg/kg) was measured eight times over a placebo in the same individuals and under the same conditions by an incremental cycling test to volitional fatigue and an adapted version of the Wingate cycling test. The ergogenic response to caffeine varied from 9% to 1% among individuals, but all participants increased both cycling power in the incremental test and Wingate mean power at least three to eight times out of eight the caffeine–placebo comparisons. These data expand the suggestion of a minimal occurrence of caffeine non-responders because it shows that all individuals responded to caffeine when caffeine is compared to a placebo on multiple and repeated testing sessions.

Topographic Quantitative EEG Response to Acute Caffeine Withdrawal: A Comprehensive Analysis of Multiple Quantitative Variables

2002 ◽  
Vol 33 (4) ◽  
pp. 178-188 ◽  
Author(s):  
Roy R. Reeves ◽  
Frederick A. Struve ◽  
Gloria Patrick
Keyword(s):  
Quantitative Eeg ◽  
Comprehensive Analysis ◽  
Relative Power ◽  
Caffeine Consumption ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Absolute Power ◽  
Caffeine Withdrawal ◽  
The Mean ◽  
Abstinence Period

Most previous studies of the neurophysiological effects of caffeine have focused on the effects of caffeine ingestion, and few studies have examined the effects of caffeine withdrawal. This open study evaluated the quantitative EEG (QEEG) changes occurring during a 4-day period of abstinence in subjects who habitually consume 300 mg or more of caffeine daily. Thirteen subjects underwent QEEG studies during their usual caffeine consumption (baseline) and on days 1,2, and 4 of a 4-day period of caffeine abstinence. Ten of the subjects underwent a second QEEG on day 4 that consisted of a period of recording after reinstitution of caffeine. A comprehensive analysis of multiple quantitative variables was performed for each study during the abstinence period and compared to the variables obtained at baseline for each subject. Changes occurring during caffeine abstinence included: 1) increases in theta absolute power over all cortical areas, 2) increases in delta absolute power over the frontal cortex, 3) decreases in the mean frequency of both the alpha and beta rhythm, 4) increase in theta relative power and decrease in beta relative power, and 5) significant changes in interhemispheric coherence. Most of these changes tended to return to pre-abstinence baseline levels rapidly after resumption of caffeine consumption. The caffeine withdrawal state affects a number of neurophysiological variables. Further investigation of the neurophysiological aspects of caffeine withdrawal using placebo controlled double blind assessment methods is warranted.

Effects of Caffeine Ingestion on Exercise-induced Change during High-Intensity Intermittent Exercise

1995 ◽  
Vol 5 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Isaiah Trice ◽  
Emily M. Haymes
Keyword(s):  
Blood Glucose ◽  
Perceived Exertion ◽  
Intermittent Exercise ◽  
Time To Exhaustion ◽  
Double Blind ◽  
Serum Free Fatty Acid ◽  
Caffeine Ingestion ◽  
Serum Free ◽  
Placebo Trial ◽  
Double Blind Design

In this study a double-blind design was used to determine the effect of caffeine on time to exhaustion and on associated metabolic and circulatory measures. Eight male subjects ingested either caffeine (5 mg/kg body weight) or a placebo 1 hr prior to exercise at 85-90% of maximum workload. Subjects were encouraged to complete three 30-min intermittent cycling periods at 70 rpm with 5 min rest between each. The exercise was terminated when the subject failed to complete three 30-min periods or failed to maintain 70 rpm for at least 15 s consecutively. Serum free fatty acids, glycerol, blood glucose, lactate, perceived exertion, heart rate, andcost were measured. The time to exhaustion was significantly longer during the caffeine trial than during the placebo trial. Serum free fatty acid levels were significantly different between trials. The decline in blood glucose levels was significantly less during the caffeine trial than during the placebo trial. There were no significant differences between trials for the other measures. It was concluded that caffeine increases time to exhaustion when trained subjects cycled intermittently at high levels of intensity.

scholarly journals Effects of creatine hydrochloride supplementation on physical performance and hormonal changes in soldiers

2021 ◽  
Vol 9 (1) ◽  
pp. 93-99
Author(s):  
Mohammad Milad Tayebi ◽  
Mitra Yousefpour ◽  
Laya Ghahari
Keyword(s):  
Physical Performance ◽  
Vertical Jump ◽  
Hormonal Changes ◽  
Power Performance ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Double Blind ◽  
Back Squat ◽  
Before And After ◽  
Army Soldiers

Purpose: The aim of this study was to examine the effects of 2 weeks of creatine hydrochloride (CrHCl) supplementation on physical performance and hormonal changes in army soldiers. Materials: Eighteen male army soldiers were randomly assigned in a double-blind fashion to either a CrHCl (n=9) or placebo (Pl) (n=9) groups. CrHCl group costumed 3g of creatine per day, whereas Pl group was given dextrose. Before and after supplementation period, the subjects performed a battery of performance tests including one repletion maximum (1RM) of bench press and back squat, vertical jump (VJ) and Wingate anaerobic test. In addition, blood samples were obtained to determine changes in testosterone and cortisol concentrations per and post supplementation. Results: There were significant increases in VJ, peak and mean power, and 1RM back squat test following the 2 weeks of CrHCl supplementation (p < 0.05) without any significant change for the Pl group. In addition significant changes were observed in testosterone and cortisol concentrations from before to after supplementation in CrHCl group (p < 0.05) and compared with Pl group (p=0.001). Conclusions: In conclusion, the present study indicates that CrHCl supplementation can improve VJ, power performance, 1RM back squat and hormonal changes in army soldiers.

Caffeine Improved Time to Exhaustion But Did Not Change Alternative Maximal Accumulated Oxygen Deficit Estimated During a Single Supramaximal Running Bout

2016 ◽  
Vol 26 (6) ◽  
pp. 549-557 ◽  
Author(s):  
Rodrigo De Araujo Bonetti De Poli ◽  
Willian Eiji Miyagi ◽  
Fabio Yuzo Nakamura ◽  
Alessandro Moura Zagatto
Keyword(s):  
Anaerobic Capacity ◽  
Oxygen Deficit ◽  
Time To Exhaustion ◽  
Placebo Condition ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Total Body Mass ◽  
Accumulated Oxygen Deficit ◽  
Negative Effect ◽  
Positive Effect

The aim of the current study was to investigate the effects of acute caffeine supplementation on anaerobic capacity determined by the alternative maximal accumulated oxygen deficit (MAODALT) in running effort. Eighteen recreational male runners [29 ± 7years; total body mass 72.1 ± 5.8 kg; height 176.0 ± 5.4cm; maximal oxygen uptake (VO2max) 55.8 ± 4.2 ml·kg-1 ·min-1] underwent a graded exercise test. Caffeine (6 mg·kg-1) or a placebo were administered 1 hr before the supramaximal effort at 115% of the intensity associated with VO2max in a double-blind, randomized cross-over study, for MAODALT assessment. The time to exhaustion under caffeine condition (130.2 ± 24.5s) was 11.3% higher (p = .01) than placebo condition (118.8 ± 24.9 s) and the qualitative inference for substantial changes showed a very likely positive effect (93%). The net participation of the oxidative phosphorylation pathway was significantly higher in the caffeine condition (p = .02) and showed a likely positive effect (90%) of 15.3% with caffeine supplementation. The time constant of abrupt decay of excess postexercise oxygen consumption (τ1) was significantly different between caffeine and placebo conditions (p = .03) and showed a likely negative effect (90%), decreasing -8.0% with caffeine supplementation. The oxygen equivalents estimated from the glycolytic and phosphagen metabolic pathways showed a possibly positive effect (68%) and possibly negative effect (78%) in the qualitative inference with caffeine ingestion, respectively. However, the MAODALT did not differ under the caffeine or placebo conditions (p = .68). Therefore, we can conclude that acute caffeine ingestion does not modify the MAODALT, reinforcing the robustness of this method. However, caffeine ingestion can alter the glycolytic and phosphagen metabolic pathway contributions to MAODALT.

The Effects of Caffeine on the Maximal Accumulated Oxygen Deficit and Short-Term Running Performance

1998 ◽  
Vol 8 (2) ◽  
pp. 95-104 ◽  
Author(s):  
Michael Doherty
Keyword(s):  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Oxygen Deficit ◽  
Preliminary Assessment ◽  
Short Term ◽  
Placebo Condition ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Running Performance ◽  
Accumulated Oxygen Deficit

The purpose of this study was to evaluate the effect of acute caffeine ingestion on the maximal accumulated oxygen deficit (MAOD) and short-term running performance. Nine well-trained males performed a preliminary assessment and. at least 4 days later, a supramaximal run to exhaustion. Their VO2max values were determined, and the MAOD test at an exercise intensity equivalent to 125% VO2max was performed. Caffeine (5 mg ⋅ kg−1) or placebo was administered 1 hr prior to the MAOD in a double-blind, randomized cross-over study. In comparison to the placebo condition, subjects in the caffeine condition developed a significantly greater MAOD and increased their run lime to exhaustion. However, posl-MAOD blood lactate concentration ([HLa]) was not different between trials for caffeine and placebo. Caffeine ingestion can be an effective ergogenic aid for short-term, supramaximal running performance and can increase MAOD. However, these results do not appear to be related to an increased [HLa).

Effects of Caffeine Ingestion on Exercise Testing: A Meta-Analysis

2004 ◽  
Vol 14 (6) ◽  
pp. 626-646 ◽  
Author(s):  
Mike Doherty ◽  
Paul M. Smith
Keyword(s):  
Exercise Testing ◽  
Meta Analysis ◽  
Time To Exhaustion ◽  
Inclusion Criteria ◽  
Short Term ◽  
Double Blind ◽  
Caffeine Ingestion ◽  
Ergogenic Effects ◽  
Endurance Testing ◽  
Type Of Exercise

This study used the meta-analytic approach to examine the effects of caffeine ingestion on exercise testing. Forty double-blind studies with 76 effect sizes (ES) met the inclusion criteria. The type of exercise test was classified as endurance, graded, or short-term. In comparison with placebo, caffeine improved test outcome by 12.3% (95% CI, 9.1 to 15.4), which was equivalent to an overall ES of 0.41 (95% CI, 0.31 to 0.51). Endurance exercise significantly improved test outcome (P < 0.05) more than either graded or short-term exercise. When exercise protocol was examined, time-to-exhaustion (Tlim) protocols had a significantly greater (P < 0.05) ES than either the graded or the non-Tlim protocol(s). The results from this meta-analysis confirm the ergogenic effects of caffeine, particularly for endurance testing that use Tlim protocols.

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