Caffeine intake improves intense intermittent exercise performance and reduces muscle interstitial potassium accumulation

The effect of oral caffeine ingestion on intense intermittent exercise performance and muscle interstitial ion concentrations was examined. The study consists of two studies (S1 and S2). In S1, 12 subjects completed the Yo-Yo intermittent recovery level 2 (Yo-Yo IR2) test with prior caffeine (6 mg/kg body wt; CAF) or placebo (PLA) intake. In S2, 6 subjects performed one low-intensity (20 W) and three intense (50 W) 3-min (separated by 5 min) one-legged knee-extension exercise bouts with (CAF) and without (CON) prior caffeine supplementation for determination of muscle interstitial K+ and Na+ with microdialysis. In S1 Yo-Yo IR2 performance was 16% better ( P < 0.05) in CAF compared with PLA. In CAF, plasma K+ at the end of the Yo-Yo IR2 test was 5.2 ± 0.1 mmol/l with no difference between the trials. Plasma free fatty acids (FFA) were higher ( P < 0.05) in CAF than PLA at rest and remained higher ( P < 0.05) during exercise. Peak blood glucose (8.0 ± 0.6 vs. 6.2 ± 0.4 mmol/l) and plasma NH3 (137.2 ± 10.8 vs. 113.4 ± 13.3 μmol/l) were also higher ( P < 0.05) in CAF compared with PLA. In S2 interstitial K+ was 5.5 ± 0.3, 5.7 ± 0.3, 5.8 ± 0.5, and 5.5 ± 0.3 mmol/l at the end of the 20-W and three 50-W periods, respectively, in CAF, which were lower ( P < 0.001) than in CON (7.0 ± 0.6, 7.5 ± 0.7, 7.5 ± 0.4, and 7.0 ± 0.6 mmol/l, respectively). No differences in interstitial Na+ were observed between CAF and CON. In conclusion, caffeine intake enhances fatigue resistance and reduces muscle interstitial K+ during intense intermittent exercise.

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EFFECT OF CAFFEINE INGESTION ON HIGH-INTENSITY INTERMITTENT EXERCISE PERFORMANCE IN ATHLETES

Medicine & Science in Sports & Exercise ◽

10.1097/00005768-199905001-02062 ◽

1999 ◽

Vol 31 (Supplement) ◽

pp. S402

Author(s):

H. K. Whelan ◽

D. T. Drinkwater

Keyword(s):

Exercise Performance ◽

High Intensity ◽

Intermittent Exercise ◽

Caffeine Ingestion

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The Effects of Caffeine Mouth Rinsing on Exercise Performance: A Systematic Review

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2020-0083 ◽

2020 ◽

Vol 30 (5) ◽

pp. 362-373

Author(s):

Alex M. Ehlert ◽

Hannah M. Twiddy ◽

Patrick B. Wilson

Keyword(s):

Exercise Performance ◽

Systemic Absorption ◽

Caffeine Intake ◽

Mouth Rinse ◽

Genetic Modifiers ◽

Improve Performance ◽

Caffeine Ingestion ◽

Positive Effects ◽

Negative Side Effects ◽

Mouth Rinsing

Caffeine ingestion can improve performance across a variety of exercise modalities but can also elicit negative side effects in some individuals. Thus, there is a growing interest in the use of caffeine mouth rinse solutions to improve sport and exercise performance while minimizing caffeine’s potentially adverse effects. Mouth rinse protocols involve swilling a solution within the oral cavity for a short time (e.g., 5–10 s) before expectorating it to avoid systemic absorption. This is believed to improve performance via activation of taste receptors and stimulation of the central nervous system. Although reviews of the literature indicate that carbohydrate mouth rinsing can improve exercise performance in some situations, there has been no attempt to systematically review the available literature on caffeine mouth rinsing and its effects on exercise performance. To fill this gap, a systematic literature search of three databases (PubMed, SPORTDiscus, and Web of Science) was conducted by two independent reviewers. The search resulted in 11 randomized crossover studies that were appraised and reviewed. Three studies found significant positive effects of caffeine mouth rinsing on exercise performance, whereas the remaining eight found no improvements or only suggestive benefits. The mixed results may be due to heterogeneity in the methods across studies, interindividual differences in bitter tasting, and differences in the concentrations of caffeine solutions. Future studies should evaluate how manipulating the concentration of caffeine solutions, habitual caffeine intake, and genetic modifiers of bitter taste influence the efficacy of caffeine mouth rinsing as an ergogenic strategy.

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Cortical substrates of the effects of caffeine and time-on-task on perception of effort

Journal of Applied Physiology ◽

10.1152/japplphysiol.00898.2013 ◽

2014 ◽

Vol 117 (12) ◽

pp. 1514-1523 ◽

Cited By ~ 52

Author(s):

Helma M. de Morree ◽

Christoph Klein ◽

Samuele M. Marcora

Keyword(s):

Vastus Lateralis ◽

Knee Extension ◽

Caffeine Intake ◽

Time On Task ◽

Force Output ◽

Double Blind ◽

Caffeine Ingestion ◽

Perceived Effort ◽

Perception Of Effort ◽

Motor Areas

Caffeine intake results in a decrease in perception of effort, but the cortical substrates of this perceptual effect of caffeine are unknown. The aim of this randomized counterbalanced double-blind crossover study was to investigate the effect of caffeine on the motor-related cortical potential (MRCP) and its relationship with rating of perceived effort (RPE). We also investigated whether MRCP is associated with the increase in RPE occurring over time during submaximal exercise. Twelve healthy female volunteers performed 100 intermittent isometric knee extensions at 61 ± 5% of their maximal torque 1.5 h after either caffeine (6 mg/kg) or placebo ingestion, while RPE, vastus lateralis electromyogram (EMG), and MRCP were recorded. RPE and MRCP amplitude at the vertex during the first contraction epoch (0–1 s) were significantly lower after caffeine ingestion compared with placebo ( P < 0.05) and were significantly higher during the second half of the submaximal intermittent isometric knee-extension protocol compared with the first half ( P < 0.05). No significant effects of caffeine and time-on-task were found for EMG amplitude and submaximal force output variables. The covariation between MRCP and RPE across both caffeine and time-on-task ( r10 = −0.335, P < 0.05) provides evidence in favor of the theory that perception of effort arises from neurocognitive processing of corollary discharges from premotor and motor areas of the cortex. Caffeine seems to reduce perception of effort through a reduction in the activity of cortical premotor and motor areas necessary to produce a submaximal force, and time-on-task has the opposite effect.

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The Effects of 3 Different Doses of Caffeine on Jumping and Throwing Performance: A Randomized, Double-Blind, Crossover Study

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2018-0884 ◽

2019 ◽

Vol 14 (9) ◽

pp. 1170-1177 ◽

Cited By ~ 18

Author(s):

Filip Sabol ◽

Jozo Grgic ◽

Pavle Mikulic

Keyword(s):

Exercise Performance ◽

Repeated Measures ◽

Vertical Jump ◽

Caffeine Intake ◽

Lower Body ◽

Acute Effects ◽

Experimental Conditions ◽

Caffeine Ingestion ◽

Ballistic Exercise ◽

Medicine Ball

Purpose: To examine the acute effects of 3 doses of caffeine on upper- and lower-body ballistic exercise performance and to explore if habitual caffeine intake affects the acute effects of caffeine ingestion on ballistic exercise performance. Methods: Twenty recreationally active male participants completed medicine-ball-throw and vertical-jump tests under 4 experimental conditions (placebo and 2, 4, and 6 mg·kg−1 of caffeine). Results: One-way repeated-measures analysis of variance (ANOVA) with subsequent post hoc analyses indicated that performance in the medicine-ball-throw test improved, compared with placebo, only with a 6 mg·kg−1 dose of caffeine (P = .032). Effect size, calculated as the mean difference between the 2 measurements divided by the pooled SD, amounted to 0.29 (+3.7%). For the vertical-jump test, all 3 caffeine doses were effective (compared with placebo) for acute increases in performance (P values .022–.044, effect sizes 0.35–0.42, percentage changes +3.7% to +4.1%). A 2-way repeated-measures ANOVA indicated that there was no significant group × condition interaction effect, suggesting comparable responses between low (≤100 mg·d−1) and moderate to high (>100 mg·d−1) caffeine users to the experimental conditions. Conclusion: Caffeine doses of 2, 4, and 6 mg·kg−1 seem to be effective for acute enhancements in lower-body ballistic exercise performance in recreationally trained male individuals. For the upper-body ballistic exercise performance, only a caffeine dose of 6 mg·kg−1 seems to be effective. The acute effects of caffeine ingestion do not seem to be affected by habitual caffeine intake; however, this requires further exploration.

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Simultaneous determination of muscle31P and O2 uptake kinetics during whole body NMR spectroscopy

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.2.742 ◽

1999 ◽

Vol 86 (2) ◽

pp. 742-747 ◽

Cited By ~ 48

Author(s):

B. J. Whipp ◽

H. B. Rossiter ◽

S. A. Ward ◽

D. Avery ◽

V. L. Doyle ◽

...

Keyword(s):

Simultaneous Determination ◽

Creatine Phosphate ◽

High Energy ◽

Knee Extension ◽

Whole Body ◽

Control Mechanisms ◽

Free Induction ◽

Measuring Module ◽

Knee Extension Exercise

Our understanding of O2 uptake (V˙o 2) control mechanisms during exercise may be improved by the simultaneous determination of the kinetics of intramuscular high-energy phosphate turnover and pulmonary V˙o 2. We therefore developed a technique for remote gas-exchange analysis while subjects exercised in a whole body 1.5-T NMR system. Knee-extension exercise was performed against restraining rubber bands in the prone position. Free induction decays were acquired every 1,875 ms by using a transmit-receive coil, which was placed under the quadriceps. This allowed 31P spectra of intramuscular ATP, Pi, and creatine phosphate dynamics to be determined every 15 s. Airflow was measured with a custom-designed turbine and a 45-ft.-long cable to reach the volume-measuring module. This was located in an adjacent radio-frequency-shielded room, as was the respiratory mass spectrometer, which also used a 45-ft.-long sampling line. The respired gas profiles were not discernibly different from those that used the standard inlet; the increase in the delay was readily incorporated into the breathby-breath algorithm, allowing theV˙o 2 kinetics to be determined in concert with those of intramuscular phosphate metabolism.

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Effects of Various Doses of Caffeine Ingestion on Intermittent Exercise Performance and Cognition

Brain Sciences ◽

10.3390/brainsci10090595 ◽

2020 ◽

Vol 10 (9) ◽

pp. 595 ◽

Cited By ~ 1

Author(s):

Cuicui Wang ◽

Yuechuan Zhu ◽

Cheng Dong ◽

Zigui Zhou ◽

Xinyan Zheng

Keyword(s):

Stroop Task ◽

Exercise Performance ◽

Power Output ◽

Intermittent Exercise ◽

Peak Power Output ◽

High Dose ◽

Double Blind ◽

Caffeine Ingestion ◽

Positive Effects ◽

The Mean

To date, no study has examined the effects of caffeine on prolonged intermittent exercise performance that imitates certain team-sports, and the suitable concentration of caffeine for improved intermittent exercise performance remains elusive. The purpose of the present cross-over, double-blind preliminary study was to investigate effects of low, moderate, and high doses of caffeine ingestion on intermittent exercise performance and cognition. Ten males performed a familiarization session and four experimental trials. Participants ingested capsules of placebo or caffeine (3, 6, or 9 mg/kg) at 1 h before exercise, rested quietly, and then performed cycling for 2 × 30 min. The cycling protocol consisted of maximal power pedaling for 5 s (mass × 0.075 kp) every minute, separated by unloaded pedaling for 25 s and rest for 30 s. At pre-ingestion of capsules, 1 h post-ingestion, and post-exercise, participants completed the Stroop task. The mean power-output (MPO), peak power-output (PPO), and response time (RT) in the Stroop task were measured. Only 3 mg/kg of caffeine had positive effects on the mean PPO and MPO; 3 mg/kg caffeine decreased RTs significantly in the incongruent and congruent conditions. These results indicate that the ingestion of low-dose caffeine had greater positive effects on the participants’ physical strength during prolonged intermittent exercise and cognition than moderate- or high-dose caffeine.

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Electromyographic activity of vastus lateralis muscle of dominant thigh (right) in relation to performance levels during the leg/knee extension exercise performance with 30 repetition maximum load

BLDE University Journal of Health Sciences ◽

10.4103/bjhs.bjhs_22_20 ◽

2020 ◽

Vol 5 (2) ◽

pp. 194

Author(s):

Dhananjoy Shaw ◽

Deepak Singh ◽

Manvinder Kaur ◽

UmeshKr Ahlawat ◽

Dinesh Bhatia

Keyword(s):

Exercise Performance ◽

Vastus Lateralis ◽

Maximum Load ◽

Knee Extension ◽

Vastus Lateralis Muscle ◽

Electromyographic Activity ◽

Performance Levels ◽

Repetition Maximum ◽

Lateralis Muscle ◽

Knee Extension Exercise

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International society of sports nutrition position stand: caffeine and exercise performance

Journal of the International Society of Sports Nutrition ◽

10.1186/s12970-020-00383-4 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Nanci S. Guest ◽

Trisha A. VanDusseldorp ◽

Michael T. Nelson ◽

Jozo Grgic ◽

Brad J. Schoenfeld ◽

...

Keyword(s):

Physical Performance ◽

Body Mass ◽

International Society ◽

Exercise Performance ◽

Sports Nutrition ◽

Exercise Session ◽

Caffeine Intake ◽

List Type ◽

Caffeine Ingestion ◽

Chewing Gums

AbstractFollowing critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions. Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals. Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg/kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect. The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session. Caffeine appears to improve physical performance in both trained and untrained individuals. Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation. Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals. Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation. The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4–6 mg/kg, respectively. Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise. Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance.

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