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Acute Effects of Caffeine Supplementation on Movement Velocity in Resistance Exercise: A Systematic Review and Meta-analysis

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Background Several studies investigated the effects of caffeine supplementation on movement velocity in resistance exercise. However, these studies presented inconsistent findings. Objective This paper aimed to: (a) review the studies that explored the effects of caffeine supplementation on movement velocity in resistance exercise; and (b) pool their results using a meta-analysis. Methods A search for studies was performed through seven databases. Random-effects meta-analyses of standardized mean differences (SMD) were performed to analyze the data. Sub-group meta-analyses explored the effects of caffeine on different velocity variables (i.e., mean and peak velocity), different loads (i.e., low, moderate, and high loads), and upper- and lower-body exercises. Results Twelve studies met the inclusion criteria. In the main meta-analysis, in which we pooled all available studies, the SMD favored the caffeine condition (SMD = 0.62; 95% confidence interval [CI]: 0.39–0.84; p < 0.001). Sub-group analyses indicated that caffeine significantly enhances mean (SMD = 0.80; 95% CI: 0.48–1.12; p < 0.001) and peak velocity (SMD = 0.41; 95% CI: 0.08–0.75; p = 0.014), movement velocity with low loads (SMD = 0.78; 95% CI: 0.41–1.14; p < 0.001), moderate loads (SMD = 0.58; 95% CI: 0.25–0.91; p = 0.001), and high loads (SMD = 0.70; 95% CI: 0.33–1.07; p < 0.001), as well as in lower-body (SMD = 0.82; 95% CI: 0.42–1.23; p < 0.001) and upper-body exercises (SMD = 0.59; 95% CI: 0.37–0.82; p < 0.001). Conclusion Acute caffeine supplementation is highly ergogenic for movement velocity in resistance exercise. Sub-group analyses indicated that caffeine ingestion is ergogenic: (a) for both mean and peak velocity; (b) for movement velocity when exercising with low, moderate and high loads, and (c) for movement velocity in both lower- and upper-body exercises. Previous meta-analyses that explored the effects of caffeine on various aspects of resistance exercise performance (i.e., muscular strength and endurance) reported trivial to moderate ergogenic effects (effect size range: 0.16–0.38). In the present meta-analysis, the pooled effect size ranged from 0.41 to 0.82. From a resistance exercise performance standpoint, this suggests that caffeine has the most pronounced performance-enhancing effects on movement velocity.
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Vol.:(0123456789)
Sports Medicine (2020) 50:717–729
https://doi.org/10.1007/s40279-019-01211-9
SYSTEMATIC REVIEW
Acute Eects ofCaeine Supplementation onMovement Velocity
inResistance Exercise: ASystematic Review andMeta‑analysis
JavierRaya‑González1· TaraRendo‑Urteaga1· RaúlDomínguez1· DanielCastillo1·
AlejandroRodríguez‑Fernández1· JozoGrgic2
Published online: 23 October 2019
© Springer Nature Switzerland AG 2019
Abstract
Background Several studies investigated the effects of caffeine supplementation on movement velocity in resistance exercise.
However, these studies presented inconsistent findings.
Objective This paper aimed to: (a) review the studies that explored the effects of caffeine supplementation on movement
velocity in resistance exercise; and (b) pool their results using a meta-analysis.
Methods A search for studies was performed through seven databases. Random-effects meta-analyses of standardized mean
differences (SMD) were performed to analyze the data. Sub-group meta-analyses explored the effects of caffeine on differ-
ent velocity variables (i.e., mean andpeak velocity), different loads (i.e., low, moderate, and high loads), and upper- and
lower-body exercises.
Results Twelve studies met the inclusion criteria. In the main meta-analysis, in which we pooled all available studies,
the SMD favored the caffeine condition (SMD = 0.62; 95% confidence interval [CI]: 0.39–0.84; p < 0.001). Sub-group
analyses indicated that caffeine significantly enhances mean (SMD = 0.80; 95% CI: 0.48–1.12; p < 0.001) and peak veloc-
ity (SMD = 0.41; 95% CI: 0.08–0.75; p = 0.014), movement velocity with low loads (SMD = 0.78; 95% CI: 0.41–1.14;
p < 0.001), moderate loads (SMD = 0.58; 95% CI: 0.25–0.91; p = 0.001), and high loads (SMD = 0.70; 95% CI: 0.33–1.07;
p < 0.001), as well as in lower-body (SMD = 0.82; 95% CI: 0.42–1.23; p < 0.001) and upper-body exercises (SMD = 0.59;
95% CI: 0.37–0.82; p < 0.001).
Conclusion Acute caffeine supplementation is highly ergogenic for movement velocity in resistance exercise. Sub-group
analyses indicated that caffeine ingestion is ergogenic: (a) for both mean and peak velocity; (b) for movement velocity when
exercising with low, moderate and high loads, and (c) for movement velocity in both lower- and upper-body exercises. Previ-
ous meta-analyses that explored the effects of caffeine on various aspects of resistance exercise performance (i.e., muscular
strength and endurance) reported trivial to moderate ergogenic effects (effect size range: 0.16–0.38). In the present meta-
analysis, the pooled effect size ranged from 0.41 to 0.82. From a resistance exercise performance standpoint, this suggests
that caffeine has the most pronounced performance-enhancing effects on movement velocity.
1 Introduction
The 2018 International Olympic Committee consensus
statement classified caffeine as a nutritional supplement
that has good evidence of benefits for enhancing exercise
performance [1]. As such, caffeine is widely consumed
by athletes [2]. Studies that examined the prevalence of
caffeine ingestion among different groups of athletes
reported that those competing in strength- and power-
based sports are among the highest users of caffeine—in
terms of the urine concentration of caffeine [2].
Many primary studies and several meta-analy-
ses have explored the effects of caffeine on muscle
strength [310]. The currently published meta-analyses
investigated the effects of caffeine on one-repetition
maximum (1RM), isokinetic, and isometric strength
[35]. These meta-analyses [35] reported ergogenic
effects of caffeine on strength in the effect size mag-
nitude of 0.16 for isokinetic strength (95% confidence
* Jozo Grgic
jozo.grgic@live.vu.edu.au
1 Faculty ofHealth Sciences, Universidad Isabel I, Burgos,
Spain
2 Institute forHealth andSport (IHES), Victoria University,
Melbourne, VIC, Australia
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Acute ingestion of caffeine seems to evoke effects on increased wakefulness, diuresis, heart rate and metabolic function, and decreased sleepiness, fatigue, rating of perceived exertion (RPE) and pain perception . Moderate-to-high quality systematic reviews provide moderate-quality evidence supporting the ergogenic benefits of caffeine on muscle endurance, muscle strength, anaerobic power, and aerobic endurance (Grgic et al. 2020). Additionally, acute caffeine supplementation seems to be highly ergogenic for movement velocity in RT, enhancing both mean and peak velocity under different loads and for both upper-and lower-body exercises (Raya-González et al. 2020). ...
... Moderate-to-high quality systematic reviews provide moderate-quality evidence supporting the ergogenic benefits of caffeine on muscle endurance, muscle strength, anaerobic power, and aerobic endurance (Grgic et al. 2020). Additionally, acute caffeine supplementation seems to be highly ergogenic for movement velocity in RT, enhancing both mean and peak velocity under different loads and for both upper-and lower-body exercises (Raya-González et al. 2020). Therefore, caffeine is well-supported for its ergogenic effects on mechanical performance in RT (Grgic et al. , 2020Raya-González et al. 2020). ...
... Additionally, acute caffeine supplementation seems to be highly ergogenic for movement velocity in RT, enhancing both mean and peak velocity under different loads and for both upper-and lower-body exercises (Raya-González et al. 2020). Therefore, caffeine is well-supported for its ergogenic effects on mechanical performance in RT (Grgic et al. , 2020Raya-González et al. 2020). To our knowledge, only one study has examined the acute effects of caffeine on supersets, although this study combined upper-body with lowerbody exercises (Jacobs et al. 2003). ...
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... gain in upper limb strength [59]. Another meta-analysis showed significant benefits of caffeine supplementation for speed-based resistance training [60]. For lower-limb strength, most studies have found that caffeine supplementation can have a performance-enhancing effect at a lower dose (2 mg/kg) compared with the upper limbs. ...
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Background: Caffeine intake in the form of chewing gum is characterized by rapid absorption and utilization. Objectives: The purpose of this study was to investigate the effects of caffeinated chewing gum on exercise performance and physiological responses in a systematic review. Methods: All articles were searched using the PubMed and Scopus databases to include articles published up to June 2024, following the Preferred Reporting Items for Systematic Evaluation and Meta-Analysis (PRISMA) protocol. Results: Thirty-two studies were finally included. Most studies have found that pre-exercise caffeinated chewing gum supplementation is effective in improving endurance, repetitive sprinting, lower limb strength, and sport-specific performance, as well as lowering rating of perceived exertion (RPE) or fatigue index even with lower dosages of caffeine. Sympathetic activation may be one of the mechanisms by which caffeinated chewing gum affects athletic performance. No significant effect on energy metabolism indicators (blood glucose, blood lactate, free fatty acids) was found. In addition, two studies found that caffeinated chewing gum reduced or maintained cortisol levels and increased testosterone levels. However, caffeinated chewing gum intake does not have an impact on catecholamines and β-endorphins. There have been inconsistent results for explosive performance, agility performance, and pain perception. Only a few studies have examined balance performance. In conclusion, a low dose of caffeine (100–300 mg or 2–4 mg/kg) in the form of chewing gum is rapidly absorbed and utilized, positively impacting most exercise and physiological performance. Conclusions: Future studies should also consider the performance variables of agility, pain perception, and explosive performance to gain a more comprehensive understanding of the effects of caffeinated chewing gum on sympathetic activation and exercise performance.
... Previous cross-sectional studies [24][25][26] investigated the relationship between lower limb asymmetry and unilateral mechanical performance. Thomas et al. [24] showed no significant relationships between dominant-non-dominant ratios and strength tests. ...
... Research also indicates small ergogenic effects on power in isokinetic, isometric, and 1RM strength tasks, with effect sizes of 0.16, 0.19, and 0.20, respectively [6][7][8][9]. While caffeine benefits aerobic exercises, its effects on anaerobic performance are less certain. ...
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Caffeine and sodium bicarbonate are extensively researched ergogenic aids known for their potential to enhance exercise performance. The stimulant properties of caffeine on the central nervous system, coupled with the buffering capacity of sodium bicarbonate, have been associated with improved athletic performance. This has led to investigations of their combined effects on strength. The aim of the present study is to investigate the effect of isolated and combined caffeine and sodium bicarbonate consumption on strength using the isometric mid-thigh pull test (IMTP). Nineteen male college students (age 23.6 ± 1.6 years) participated in this crossover, double-blind, placebo-controlled study. They were exposed to the following conditions: control (no supplement), placebo (20 g maltodextrin), caffeine (6 mg/kg), sodium bicarbonate (0.3 g/kg), and a combination of caffeine and sodium bicarbonate. Supplements and placebo were diluted in water and consumed 60 min prior to the IMTP tests. Two 5 s IMTP trials were performed at 40–60% and 60–80% of One Repetition of Maximum (1RM) with a 60 s rest between. Consumption of caffeine or Caf + NaHCO3 did not significantly change peak IMTP strength values at any intensity (p = 0.110). The peak IMTP values did not show significant differences between conditions or from control condition values (1091 ± 100 N) to Caf (1224 ± 92 N), NaHCO3 (1222 ± 74 N), and Caf ± NaHCO3 (1152 ± 109 N). However, the test of the results of the ANOVA analysis of repeated measures of effect within the caffeine condition was significant for the increase in IMTP relative strength compared to control (p < 0.05). Thus, the IMTP force values increased significantly from control to Caf (p = 0.016) and from Pla to Caf (p = 0.008), but not for other comparisons (p > 0.05). In summary, caffeine supplementation alone, taken 60 min before exercise, positively affects submaximal strength performance. In contrast, sodium bicarbonate, whether taken alone or in combination with caffeine, does not enhance submaximal strength in the IMTP tests.
... The trainer also determined each participant's onerepetition maximum (1RM) for both exercises. Bench press and back squat exercises were chosen as they target major muscle groups in the upper and lower body, respectively, and have been previously used to investigate the performance-enhancing effects of caffeine on muscular strength, power, and endurance [28]. Data obtained from visit one were not used to test the hypothesis of the study. ...
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Background: This study assessed the impact of acute caffeine intake on muscular strength, power, and endurance performance between resistance-trained male and female individuals according to load in upper- and lower-body exercises. Methods: Here, 76 resistance-trained individuals (38 females, 38 males) participated in a study comparing caffeine and a placebo. Each received either 3 mg/kg of caffeine or a placebo 60 min before tests measuring muscular strength and power through bench press and back squat exercises at different intensities (25%, 50%, 75%, 90% 1RM). Muscular endurance at 65% 1RM was also assessed by performing reps until reaching task failure. Results: Compared to placebo, caffeine increased mean, peak and time to reach peak velocity and power output (p < 0.01, ηp² = 0.242–0.293) in the muscular strength/power test in males and females. This effect was particularly observed in the back squat exercise at 50%, 75% and 90% 1RM (2.5–8.5%, p < 0.05, g = 1.0–2.4). For muscular endurance, caffeine increased the number of repetitions, mean velocity and power output (p < 0.001, ηp² = 0.177–0.255) in both sexes and exercises (3.0–8.9%, p < 0.05, g = 0.15–0.33). Conclusions: Acute caffeine intake resulted in a similar ergogenic effect on muscular strength, power, and endurance performance in upper- and lower-body exercises for male and female resistance-trained participants.
... In this sense, a more recent meta-analysis has already responded to this last suggestion, concluding that caffeine is highly effective in improving speed in resistance exercises. This effect was observed at low, medium and high loads for both upper and lower limbs [12]. In an opinion article commissioned by a fight magazine, we discussed the benefits of using caffeine for fighters, associating its use with improving the performance of these athletes [13]. ...
... A test was also carried out to determine the 1RM of each participant in back squat and bench press, so that the load used during the two days of testing would be individualised and always the same. Bench press and back squat exercises were selected as they represent major upper-and lower-body muscle group loads and both have been studied previously to analyse the ergogenic effect of caffeine on muscular strength, power and endurance [30]. Both exercises were performed using a Smith machine (Multipower, Technogym, Spain) in which 2 vertical guides regulated the barbell movement. ...
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This study aimed to analyse the placebo effect associated with a high dose of caffeine (9 mg/kg) on heart rate and its variability and on strength tests. Methods: 18 participants experienced in strength training (19.7 ± 2.3 years; 72.2 ± 15.0 kg; 169.6 ± 9.0 cm) performed two days of trials (caffeine-informed/placebo-ingested (placebo) and non-ingested (control)). Firstly, heart rate and its variability were measured while participants lay down for 15 min. After that, bench press and squat tests were performed at 3 different loads (50%, 75% and 90% of 1RM). Perception of performance, effort and side effects were also evaluated. Results: no differences were found in the vast majority of strength variables analysed. Resting heart rate decreased in the placebo trial (60.39 ± 10.18 bpm control vs. 57.56 ± 9.50 bpm placebo, p = 0.040), and mean RR increased (1020.1 ± 172.9 ms control vs. 1071.5 ± 185.7 ms placebo, p = 0.032). Heart rate variability and perception of performance and effort were similar between conditions (p > 0.05 in all cases). Side effects such as activeness and nervousness were reported while consuming the placebo. Conclusions: the placebo effect did not modify performance in the majority of the strength test variables, HRV and perception of performance and effort. However, resting heart rate was reduced, mean RR increased, and some side effects appeared in the placebo trial.
... Most team sport studies focusing on athlete nutrition have reported on the health-and performance-related positive effects of diets [5,6] and supplementation [7][8][9]. However, some promising data have emerged regarding the efficacy of nutrition education interventions in team sports [10]. ...
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... Athletes of individual sports or athletes of sports with an aerobic-like nature (i.e., rowing, cycling, triathlon, etc.) are more prone to using caffeine in competition [11]. Although nowadays there is solid evidence about the ergogenic effect of caffeine on strength performance [8,12,13], there were controversial results on this topic years ago [14]. In contrast, the ergogenic properties of caffeine on endurance performance have been well-established for a long time [9,[15][16][17], and athletes in these sports could be more prone to generate expectancies about its positive effects. ...
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Background Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power. Methods A search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model. Results Ten studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147). Conclusion The meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.
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Purpose: To explore the effects of three doses of caffeine on muscle strength and muscle endurance. Methods: Twenty-eight resistance-trained men completed the testing sessions under five conditions: no-placebo control, placebo-control, and with caffeine doses of 2, 4, and 6 mg.kg−1. Muscle strength was assessed using the one-repetition maximum (1RM) test; muscle endurance was assessed by having the participants perform a maximal number of repetitions with 60% 1RM. Results: In comparisons with both control conditions, only a caffeine dose of 2 mg.kg−1 enhanced lower-body strength (d=0.13–0.15). In comparisons with the no-placebo control condition, caffeine doses of 4 mg.kg−1 and 6 mg.kg−1 enhanced upper-body strength (d=0.07–0.09) with a significant linear trend for the effectiveness of different doses of caffeine (p=0.020). Compared to both control conditions, all three caffeine doses enhanced lower-body muscle endurance (d=0.46–0.68). For upper-body muscle endurance, we did not find significant effects of caffeine. Conclusions: We found a linear trend between the dose of caffeine and its effects on upper-body strength. This study found no clear association between the dose of caffeine and the magnitude of its ergogenic effects on lower-body strength and muscle endurance. From a practical standpoint, the magnitude of caffeine’s effects on strength is of questionable relevance. A low dose of caffeine (2 mg.kg−1)—for an 80kg individual, this dose of caffeine contained in one to two cups of coffee—may produce substantial improvements in lower-body muscle endurance with the magnitude of the effect being similar to that attained using higher doses of caffeine.
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Purpose: To examine the acute effects of three doses of caffeine on upper- and lower-body ballistic exercise performance, and to explore if habitual caffeine intake impacts 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 four experimental conditions (placebo, 2, 4, and 6 mg·kg-1 of caffeine). Results: One-way repeated measures ANOVA with subsequent post hoc analyses indicated that performance in the medicine ball throw test improved, compared to placebo, only with a 6 mg·kg-1 dose of caffeine (P=0.032). Effect size, calculated as the mean difference between the two measurements divided by the pooled standard deviation, amounted to 0.29 (+3.7%). For the vertical jump test, all three caffeine doses were effective (compared to placebo) for acute increases in performance (P values ranged from 0.022 to 0.044; effect sizes from 0.35 to 0.42; percent changes from +3.7% to +4.1%). A two-way repeated measures ANOVA indicated that there was no significant group x condition interaction effect, suggesting comparable responses between low (<100 mg·day-1) and moderate-to-high (>100 mg·day-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 impacted by habitual caffeine intake; however, this requires further exploration.
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Objectives The aims of this paper are threefold: (1) to summarize the research examining the effects of caffeine on isokinetic strength, (2) pool the effects using a meta-analysis, and (3) to explore if there is a muscle group or a velocity specific response to caffeine ingestion. Design Meta-analysis. Methods PubMed/MEDLINE, Scopus, and SPORTDiscus were searched using relevant terms. The PEDro checklist was used for the assessment of study quality. A random-effects meta-analysis of standardized mean differences (SMDs) was done. Results Ten studies of good and excellent methodological quality were included. The SMD for the effects of caffeine on strength was 0.16 (95% CI = 0.06, 0.26; p = 0.003; +5.3%). The subgroup analysis for knee extensor isokinetic strength showed a significant difference (p = 0.004) between the caffeine and placebo conditions with SMD value of 0.19 (95% CI = 0.06, 0.32; +6.1%). The subgroup analysis for the effects of caffeine on isokinetic strength of other, smaller muscle groups indicated no significant difference (p = 0.092) between the caffeine and placebo conditions. The subgroup analysis for knee extensor isokinetic strength at angular velocities of 60°·s−1 and 180°·s−1 showed a significant difference between the caffeine and placebo conditions with SMD value of 0.21 (95% CI = 0.07, 0.36; p = 0.004; +6.0%) and 0.23 (95% CI = 0.07, 0.38; p = 0.005; +5.5%), respectively. No significant effect (p = 0.193) was found at an angular velocity of 30°·s−1. Conclusions This meta-analysis demonstrates that acute caffeine ingestion caffeine may significantly increase isokinetic strength. Additionally, this meta-analysis reports that the effects of caffeine on isokinetic muscular strength are predominantly manifested in knee extensor muscles and at greater angular velocities.