ECSS Paris 2023: OP-PN18
INTRODUCTION: Buccal caffeine absorption bypasses digestion, can elicit peak serum caffeine concentration within ~30 min of administration, potentially accelerating cognitive benefits compared to ingestion. Caffeine mouth sprays are commercial products that involve sublingual delivery, but their ability to increase blood caffeine remains largely unknown. METHODS: This study investigated whether caffeine mouth spray can accelerate the time to peak serum caffeine concentration compared to coffee or an energy drink. Fourteen regular caffeine users (6 males, 8 females; 24 ± 3 years, 69.9 ± 9.3 kg) abstained from caffeine for 16 h, ate a standardized breakfast, then consumed 60 mg of caffeine via either mouth spray, coffee, or energy drink in a randomized, crossover, open-label design (osf.io/m9t3v). Serum caffeine concentration was determined at baseline as well as 5, 10, 20, 30, 45, 60, 75, and 90-min post-caffeine ingestion via commercial enzyme linked immunosorbent assay. Blood pressure was measured via automated oscillometric cuff (BpTRU). At ~30 and ~90 min post-ingestion, cognitive function was assessed via Stroop test and digit symbol substitution task (Inquisit version 6, millisecond, Seattle, USA). RESULTS: Serum caffeine level increased from baseline in all conditions (p<0.0001) but did not differ between the mouth spray, coffee, and energy drink at any time point (all p>0.06). Caffeine area under the curve was not different after mouth spray, coffee, or energy drink (61 [54-73], 82 [51-119], 68 [43-78] min*mg/L respectively, p=0.22) nor was peak concentration (1.6 [1.2-1.8], 1.9 [1.4-2.4], 1.2 [0.8-3.0] mg/L respectively, p=0.19). Within the mouth spray condition, serum caffeine was higher than baseline from 10 to 90 min (p<0.03) but not at 5 min (p=0.50), and peak concentration occurred 90-min after use. Average response latency per Stroop test (Time p<0.0001) was different at all timepoints (baseline = 667±81 ms, 30 min = 710±89 ms, 90 min = 770±154 ms, p<0.02 for all), but was unaffected by condition (p=0.83) or time*condition (p=0.27). The number of correct responses relative to total responses and total correct responses on the digit symbol substitution task were unaffected by time, condition, or their interaction (p > 0.22 for all). Systolic blood pressure (time p=0.002) was higher at 60 and 90 min vs. baseline (baseline: 102±7, 30-min: 106±7; 90-min: 105±8 mmHg, p<0.03 for both), but unaffected by condition (p=0.20) or time*condition (p=0.60). Diastolic blood pressure was 69±7 mmHg at baseline, 69±6 mmHg at 30 min, and 71±7 mmHg at 90 min (time p=0.08, condition p=0.32, time*condition p=0.92). CONCLUSION: In conclusion, sublingual caffeine administration via mouth spray did not accelerate the time to peak serum caffeine nor induce cognitive benefits compared to caffeinated beverages.
Read CV Jamie BurrECSS Paris 2023: OP-PN18
INTRODUCTION: We have previously shown that training quality was reduced in elite athletes who undertook a low-CHO high-fat diet ketogenic LCHF diet. We wanted to confirm the reduced training metrics associated with such an intervention using an improved methodology, and to investigate whether this could be attenuated with caffeine supplementation. We also wanted to investigate effects of caffeine supplementation on cognitive function after exercise. METHODS: Tier 3-5 (national to internation) level race-walkers (n=21) completed 3 weeks of periodized training while adhering to diets of chronic LCHF or high carbohydrate availability (HCHO). During baseline, where all athletes followed HCHO, and then 3 intervention weeks, we monitored training quality and cognitive performance during a weekly tempo session (14 km with a 450 m elevation gain). On weeks 2 and 3, in a randomized crossover allocation, participants received 3 mg/kg caffeine or placebo (gum), 20 min before the session. Race-walking speed, heart rate, RPE, blood metabolites and Stroop word-color test metrics were collected. RESULTS: Although LCHF athletes walked at a higher percentage of VO2max speed at baseline compared to HCHO (+3.4%, p = 0.04), relative speeds during Weeks 2 and 3 were lower (-5.2%; p = 0.01 and -4.4%; p = 0.05, respectively). Hill course completion for LCHF was slower by ~7 min (Week 1) to ~3 min (Week 3), compared to a 3.5 min improvement (Week 3) from baseline in the HCHO group. Compared to baseline, the 14 km hill session was faster (p = 0.01) with caffeine than placebo, without detectable differences in the magnitude of the effect between groups (HCHO: +2.9%, LCHF: +2.0%; p=0.66). Post-exercise Stroop metrics were also improved. CONCLUSION: Caffeine supplementation partially rescued the performance impairment associated with an LCHF diet, but training quality remained lower than the combination of caffeine and high CHO availability.
Read CV Louise BurkeECSS Paris 2023: OP-PN18
INTRODUCTION: The intake of between 3 and 6 mg/kg of caffeine increases the rate of fat oxidation during moderate-intensity exercise (1). Previous research has been conducted under highly standardized laboratory conditions which are different to real applicable contexts (2). Therefore, the objective of the present study was to determine the effect of caffeine intake on fat oxidation during a 1-h mountain bike session at Fatmax (i.e., the intensity at which maximal fat oxidation occurs). The hypothesis is that caffeine will lead to an increase in fat oxidation rate, as previously observed in laboratory settings (2). METHODS: A double-blind, randomized, counterbalanced and crossover experimental design was performed by 11 participants (male, healthy, recreational athletes with cycling experience, VO2max = 49.1 ± 9.0 ml/kg/min) Participants conducted a pre-experimental incremental test on a cycloergometer to determine VO2max and Fatmax. Cyclists ingested either 3 mg/kg caffeine or a placebo 60 min before completing a 1-h mountain bike test on a trail circuit at Fatmax in which O2 uptake and CO2 production was analysed through a portable gas analyzer. The circuit was designed by the research team with the aim of simulating a real mountain bike circuit. The intensity was fixed in both conditions using Global Position System (GPS) data, potentiometer pedals and split times Statistical Package for Social Sciences software (SPSS, v.25, IBM, United States) was used to conduct the statistical analyses, and t-tests for related samples and two-way repeated measures ANOVA were performed. For the post-hoc analysis, the DMS adjustment factor was used. RESULTS: No significant effects of caffeine on the amount of fat oxidized (31.43 ± 14.39 g vs. 28.40 ± 10.81 g; p = 0.23), and carbohydrates oxidized (86.05 ± 32.33 g vs. 88.86 ± 42.64 g) were found (p = 0.26). Differences between conditions were neither observed in heart rate (131.73 ± 16.8 bpm vs. 132.64 ± 22.60 bpm; p = 0.74) nor perceived exertion during the test (9.8 ± 1.83 a.u. vs. 10.32 ± 1.96 a.u.; p = 0.12). CONCLUSION: In conclusion, caffeine intake had no effect on fat oxidation during a 1-h mountain bike test at Fatmax. The differences observed between these results and those obtained using laboratory cycloergometers may be related to a reduced metabolic effect of caffeine provoked by the inclusion of an important technical component in the mountain bike test or altered by the different individual responses of participants. Future research with participants of a more homogeneous sport level and including both men and women would be of interest. REFERENCES: 1. Collado-Mateo D, et al. Effect of acute caffeine intake on the fat oxidation rate during exercise: A systematic review and meta-analysis. Nutrients, 2020. 12(12): p. 1-18. 2. Ruiz-Moreno, C, et al. Caffeine increases whole-body fat oxidation during 1 h of cycling at Fatmax. European Journal of Nutrition, 2021. 60(4): p. 2077-2085.
Read CV Adrián Rodríguez CastañoECSS Paris 2023: OP-PN18