Coffee and Caffeine Ingestion Have Little Effect on Repeated Sprint Cycling in Relatively Untrained Males

International society of sports nutrition position stand: coffee and sports performance

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).

Low and Moderate Doses of Caffeinated Coffee Improve Repeated Sprint Performance in Female Team Sport Athletes

The aim of this study was to determine the effect of low and moderate doses of caffeine ingestion via caffeinated coffee on repeated sprint test (RST) and plasma catecholamine concentration in trained female team-sport athletes. In a randomized, double-blind, crossover design, 13 female team-sport athletes (VO2max: 48.7 ± 4 mL·kg·min−1) completed three RST trials, separated by 4-day, 60 min post-ingestion of either 3 mg·kg−1 (LCOF) or 6 mg·kg−1 (MCOF) or placebo (PLA). The RST consisted of 12 × 4 s sprints on a cycle ergometer interspersed with 20 s of active recovery. Blood lactate (BLa) and glucose (GLU) and epinephrine and norepinephrine concentrations were collected before and 60 min after coffee ingestion, and after RST. Heart rate (HR) and ratings of perceived exertion (RPE) were measured at the beginning of RST, and after the 6th and 12th sprints. Average peak power score during RST was significantly improved after LCOF (p = 0.016) and MCOF (p = 0.041) compared to PLA, but peak and mean power output of the individual sprints, and fatigue index were not different between trials (all p > 0.05). Epinephrine and norepinephrine concentrations were significantly higher before and after RST in LCOF and MCOF compared to PLA (all p < 0.05). BLa was also higher after RST in both LCOF and MCOF compared to PLA (p = 0.005). HR, RPE, and GLU were not different between conditions (p > 0.05). In conclusion, low and moderate dose of caffeine ingestion can enhance the average peak power score during repeated sprints. These findings partly support low and moderate doses of caffeine supplementation via coffee as a nutritional ergogenic aid for trained female team-sport players during repeated sprint exercise.

The Effects of Acute Caffeine Supplementation on Repeated-Sprint Ability in Healthy Young Non-Athletes

The ergogenic effects of caffeine supplementation on repeated-sprint ability (RSA) have produced equivocal results. This study aimed to examine the effects of 200 mg of caffeine during repeated-sprint running on heart rate (HR), rating of perceived exertion (RPE), blood lactate (BLa) concentration, and sprint time (ST). Thirty-two individuals (males: n = 17, females: n = 15; age: 22 ± 1 years) participated in the study. The study followed a double-blind, randomized, placebo-controlled, crossover design, in which each participant ingested 200 mg of caffeine or placebo on separate visits 60 minutes prior to repeated-sprinting exercise. The repeated-sprint protocol consisted of three sets of six maximal-effort 30-meter sprints with 20 seconds and 5 minutes of active recovery in between sprints and sets, respectively. During each set, HR, RPE, BLa, and ST were recorded. Caffeine supplementation did not significantly (set 1: p = 0.535; set 2: p = 0.602; set 3: p = 0.189) impact HR during exercise. Similarly, RPE was not statistically (p = 0.052) altered between conditions during any of the sprint sets. The caffeine trials elicited greater BLa values after all three sets compared to the placebo trials (p < 0.001). Moreover, the caffeine trials demonstrated significantly reduced total STs during all sets compared to the placebo trials (p < 0.001). Thus, our findings suggested that 200 mg of caffeine supplementation elicited an increase in RSA in young, healthy non-athletes. These findings are accompanied by a blunted perceived exertion relative to an increase in exercise intensity during repeated-sprint exercise.

Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis

INTRODUCTION

Placebos are used as a control treatment that is meant to be indistinguishable from the active intervention. However, where substantive placebo effects may occur, studies that do not include a nonplacebo control arm may underestimate the overall effect of the intervention (active plus placebo components). This study aimed to determine the relative magnitude of the placebo effect associated with nutritional supplements (caffeine and extracellular buffers) by meta-analyzing data from studies containing both placebo and nonplacebo control sessions.

METHODS

Bayesian multilevel meta-analysis models were used to estimate pooled effects and express the placebo effect as a percentage of the overall intervention effect.

RESULTS

Thirty-four studies were included, with the median pooled effect size (ES0.5) indicating a very small (ES0.5 = 0.09 (95% credible interval (CrI), 0.01-0.17)) improvement in the performance of placebo compared with control. There was no moderating effect of exercise type (capacity or performance), exercise duration, or training status. The comparison between active intervention and control indicated a small to medium effect (ES0.5 = 0.37 (95% CrI, 0.20-0.56)). Expressed in relative terms, the placebo effect was equivalent to 25% (75% CrI, 16%-35%) and 59% (75% CrI, 34%-94%) of the total intervention effect for buffers and caffeine.

CONCLUSIONS

These results demonstrate a very small but potentially important placebo effect with nutritional supplementation studies. A substantive proportion of supplement effects may be due to placebo effects, with the relative proportion influenced by the magnitude of the overall ergogenic effect. Where feasible, intervention studies should use nonplacebo control-arm comparators to identify the proportion of the effect estimated to come from placebo effects and avoid underestimating the overall benefits that the physiological plus psychobiological aspects associated with an intervention provide in the real world.

Is Coffee a Useful Source of Caffeine Preexercise?

Caffeine is a well-established ergogenic aid, with its performance-enhancing effects demonstrated across a wide variety of exercise modalities. Athletes tend to frequently consume caffeine as a performance enhancement method in training and competition. There are a number of methods available as a means of consuming caffeine around exercise, including caffeine anhydrous, sports drinks, caffeine carbohydrate gels, and gum. One popular method of caffeine ingestion in nonathletes is coffee, with some evidence suggesting it is also utilized by athletes. In this article, we discuss the research pertaining to the use of coffee as an ergogenic aid, exploring (a) whether caffeinated coffee is ergogenic, (b) whether dose-matched caffeinated coffee provides a performance benefit similar in magnitude to caffeine anhydrous, and (c) whether decaffeinated coffee consumption affects the ergogenic effects of a subsequent isolated caffeine dose. There is limited evidence that caffeinated coffee has the potential to offer ergogenic effects similar in magnitude to caffeine anhydrous; however, this requires further investigation. Coingestion of caffeine with decaffeinated coffee does not seem to limit the ergogenic effects of caffeine. Although caffeinated coffee is potentially ergogenic, its use as a preexercise caffeine ingestion method represents some practical hurdles to athletes, including the consumption of large volumes of liquid and difficulties in quantifying the exact caffeine dose, as differences in coffee type and brewing method may alter caffeine content. The use of caffeinated coffee around exercise has the potential to enhance performance, but athletes and coaches should be mindful of the practical limitations.

Coffee Ingestion Enhances 1-Mile Running Race Performance

Context: Caffeine, often in the form of coffee, is frequently used as a supplement by athletes in an attempt to facilitate improved performance during exercise. Purpose: To investigate the effectiveness of coffee ingestion as an ergogenic aid prior to a 1-mile (1609 m) race. Methods: In a double-blind, randomized, cross-over, and placebo-controlled design, 13 trained male runners completed a 1-mile race 60 minutes following the ingestion of 0.09 g·kg−1 coffee (COF), 0.09 g·kg−1 decaffeinated coffee (DEC), or a placebo (PLA). All trials were dissolved in 300 mL of hot water. Results: The race completion time was 1.3% faster following the ingestion of COF (04:35.37 [00:10.51] min:s.ms) compared with DEC (04:39.14 [00:11.21] min:s.ms; P = .018; 95% confidence interval [CI], −0.11 to −0.01; d = 0.32) and 1.9% faster compared with PLA (04:41.00 [00:09.57] min:s.ms; P = .006; 95% CI, −0.15 to −0.03; d = 0.51). A large trial and time interaction for salivary caffeine concentration was observed (P < .001; ), with a very large increase (6.40 [1.57] μg·mL−1; 95% CI, 5.5–7.3; d = 3.86) following the ingestion of COF. However, only a trivial difference between DEC and PLA was observed (P = .602; 95% CI, −0.09 to 0.03; d = 0.17). Furthermore, only trivial differences were observed for blood glucose (P = .839; ) and lactate (P = .096; ) and maximal heart rate (P = .286; ) between trials. Conclusions: The results of this study show that 60 minutes after ingesting 0.09 g·kg−1 of caffeinated coffee, 1-mile race performance was enhanced by 1.9% and 1.3% compared with placebo and decaffeinated coffee, respectively, in trained male runners.