Correction: Effect of caffeine ingestion on anaerobic capacity quantified by different methods.
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ABSTRACT:
SUBMITTER: Arcoverde L
PROVIDER: S-EPMC5557578 | biostudies-other | 2017
REPOSITORIES: biostudies-other
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Project description:We investigated whether caffeine ingestion before submaximal exercise bouts would affect supramaximal oxygen demand and maximal accumulated oxygen deficit (MAOD), and if caffeine-induced improvement on the anaerobic capacity (AC) could be detected by different methods. Nine men took part in several submaximal and supramaximal exercise bouts one hour after ingesting caffeine (5 mg·kg-1) or placebo. The AC was estimated by MAOD, alternative MAOD, critical power, and gross efficiency methods. Caffeine had no effect on exercise endurance during the supramaximal bout (caffeine: 131.3 ± 21.9 and placebo: 130.8 ± 20.8 s, P = 0.80). Caffeine ingestion before submaximal trials did not affect supramaximal oxygen demand and MAOD compared to placebo (7.88 ± 1.56 L and 65.80 ± 16.06 kJ vs. 7.89 ± 1.30 L and 62.85 ± 13.67 kJ, P = 0.99). Additionally, MAOD was similar between caffeine and placebo when supramaximal oxygen demand was estimated without caffeine effects during submaximal bouts (67.02 ± 16.36 and 62.85 ± 13.67 kJ, P = 0.41) or when estimated by alternative MAOD (56.61 ± 8.49 and 56.87 ± 9.76 kJ, P = 0.91). The AC estimated by gross efficiency was also similar between caffeine and placebo (21.80 ± 3.09 and 20.94 ± 2.67 kJ, P = 0.15), but was lower in caffeine when estimated by critical power method (16.2 ± 2.6 vs. 19.3 ± 3.5 kJ, P = 0.03). In conclusion, caffeine ingestion before submaximal bouts did not affect supramaximal oxygen demand and consequently MAOD. Otherwise, caffeine seems to have no clear positive effect on AC.
| S-EPMC5472322 | biostudies-literature
Project description:PURPOSE:The purpose of the present study was to test if caffeine ingestion affects rifle shooting accuracy in trained shooters. METHODS:Twenty trained shooters performed 4 shooting tests in a randomized, double-blinded, placebo controlled crossover design; 2 identical tests after placebo ingestion and 2 after ingestion of 300 mg caffeine. The tests consisted of 30 shots in prone position and 30 in standing position on a 10 ring electronic target, on a distance of 50 metres, without any time limit, at rest. RESULTS:Caffeine supplementation entailed a mean decrease in shooting performance by 11.8 points (95% CI: 6.7 to 17.0, effect size: 0.9). This was primarily a result of an 11.3 (95% CI: 7.2 to 15.4, effect size: 0.9) point decrease during shooting in standing position and not in prone position (0.6 point decrease, 95% CI: -2.1 to 3.2, effect size: 0.1). CONCLUSIONS:We conclude that prior ingestion of 300 mg caffeine impairs rifle shooting accuracy in trained shooters when performed in standing but not in prone position.
| S-EPMC6822722 | biostudies-literature
Project description:BackgroundIt is currently unclear whether pre-exercise caffeine ingestion can improve free-throw shooting performance, a vital skill in basketball. The purpose of this study was to investigate the effects of caffeine on free-throw shooting performance in college-aged basketball players.MethodsTwelve males (23.1 ± 1.9 years; 180.1 ± 8.8 cm; 77.1 ± 12.4 kg) and six females (22.0 ± 1.3 years; 169.4 ± 8.9 cm; 67.0 ± 11.1 kg) who competed at the college level ingested 6 mg per kg of body mass of (a) caffeine or (b) maltodextrin (placebo) on two separate occasions in a random order. After 60 min, they performed five sets of a match-simulated basketball protocol comprising six sideline-to-sideline sprints on a standard basketball court followed by two free-throws after each set. The number of successful shots was counted. Heart rate and rating of perceived exertion (RPE) after each sprint set were also recorded.ResultsCaffeine ingestion did not improve overall free-throw success (caffeine = 6.1 ± 1.7 vs. placebo = 5.5 ± 2.0; p = 0.34) compared with placebo across all five sets. There was no change in shooting accuracy across sprint sets in either trial despite significant increases in both heart rate and RPE. Caffeine increased heart rate (p = 0.02) but had no effect on RPE (p = 0.57) across five sets compared with placebo.ConclusionsIngestion of 6 mg of caffeine per kg of body mass did not improve basketball free-throw performance. Free-throw performance did not deteriorate with increasing number of sprint sets.
| S-EPMC6939085 | biostudies-literature
Project description:Mr K, aged 48, was found sweating by his partner at home at 11.50 pm. He claimed to have attempted suicide. She immediately called the Emergency Unit to ask for support. At the phone, the physician on duty indicated her to give a pill of Lysanxia (prazepam) to decrease the level of stress of the victim. However, the clinical situation worsened and he was taken to the hospital at 1.00 am. At his arrival at 1.28 am he was in cardiac arrest. Despite intensive resuscitation manoeuvres, death was pronounced at 2.30 am. At home, an empty plastic bag with a 100 g caffeine label was found. The drug was bought via Internet 6 months earlier. External body examination and autopsy revealed the lack of any traumatic injury.During examination, the pathologist collected peripheral blood (femoral blood). This specimen was tested for ethanol, volatiles, pharmaceuticals and drugs of abuse, using head space GC/FID and GC/MS, ELISA, LC-DAD, GC/MS and LC/MS/MS. Ethanol tested negative in blood. Using a dedicated LC/MS/MS procedure, caffeine was identified at 401 mg/l, which can correspond to a fatal concentration. Nordiazepam, sertraline and fluoxetine, the prescribed medications of the victim, were identified at therapeutic concentrations, 188, 31, and 48 ng/ml, respectively. Amiodarone was also identified at high concentration (4200 ng/ml), part of the medical assistance of the rescue team.The manner of death was considered as acute intoxication with caffeine.
| S-EPMC5514181 | biostudies-other
Project description:IntroductionTo date, no study has compared anaerobic capacity (AnC) estimates computed with the maximal accumulated oxygen deficit (MAOD) method and the gross energy cost (GEC) method applied to treadmill running exercise.PurposeFour different models for estimating anaerobic energy supply during treadmill running exercise were compared.MethodsFifteen endurance-trained recreational athletes performed, after a 10-min warm-up, five 4-min stages at ∼55-80% of peak oxygen uptake, and a 4-min time trial (TT). Two linear speed-metabolic rate (MR) regression models were used to estimate the instantaneous required MR during the TT (MR TT_req ), either including (5+Y LIN ) or excluding (5-Y LIN ) a measured Y-intercept. Also, the average GEC (GEC AVG ) based on all five submaximal stages, or the GEC based on the last submaximal stage (GEC LAST ), were used as models to estimate the instantaneous MR TT_req . The AnC was computed as the difference between the MR TT_req and the aerobic MR integrated over time.ResultsThe GEC remained constant at ∼4.39 ± 0.29 J⋅kg-1⋅m-1 across the five submaximal stages and the TT was performed at a speed of 4.7 ± 0.4 m⋅s-1. Compared with the 5-Y LIN , GEC AVG , and GEC LAST models, the 5+Y LIN model generated a MR TT_req that was ∼3.9% lower, with corresponding anaerobic capacities from the four models of 0.72 ± 0.20, 0.74 ± 0.16, 0.74 ± 0.15, and 0.54 ± 0.14 kJ⋅kg-1, respectively (F 1.07,42 = 13.9, P = 0.002). The GEC values associated with the TT were 4.22 ± 0.27 and 4.37 ± 0.30 J⋅kg-1⋅m-1 for 5+Y LIN and 5-Y LIN , respectively (calculated from the regression equation), and 4.39 ± 0.28 and 4.38 ± 0.27 J⋅kg-1⋅m-1 for GEC AVG and GEC LAST , respectively (F 1.08,42 = 14.6, P < 0.001). The absolute typical errors in AnC ranged between 0.03 and 0.16 kJ⋅kg-1 for the six pair-wise comparisons and the overall standard error of measurement (SEM) was 0.16 kJ⋅kg-1.ConclusionThese findings demonstrate a generally high disagreement in estimated anaerobic capacities between models and show that the inclusion of a measured Y-intercept in the linear regression (i.e., 5+Y LIN ) is likely to underestimate the MR TT_req and the GEC associated with the TT, and hence the AnC during maximal 4-min treadmill running.
| S-EPMC8371633 | biostudies-literature
Project description:To screen for xenobiotic-metabolizing-enzyme genes (XME) induced by caffeine exposure, a microarray experiment (performed with a Drosophila pangenomic array (Agilent 4 X 44K) was carried out between control and individuals exposed to caffeine (18mM ). Among 23401 genes consistantly found in the three biological replicates, 13108 showed a significant variation. 749 genes were over-expressed whereas 1518 were under-expressed. Interestingly, several genes belonging to all major classes of detoxification enzymes including XME were among the most highly induced such as CYP12d1, CYP6a8 and CYP6d5.
2014-07-04 | GSE59084 | GEO
Project description:To screen for xenobiotic-metabolizing-enzyme genes (XME) induced by caffeine exposure, a microarray experiment (performed with a Drosophila pangenomic array (Agilent 4 X 44K) was carried out between control and individuals exposed to caffeine (18mM ). Among 23401 genes consistantly found in the three biological replicates, 13108 showed a significant variation. 749 genes were over-expressed whereas 1518 were under-expressed. Interestingly, several genes belonging to all major classes of detoxification enzymes including XME were among the most highly induced such as CYP12d1, CYP6a8 and CYP6d5. Caffeine ingestion induced gene expression in Drosophila melanogaster male thorax and abdomen was mesured at 12h after exposure to doses of 0, 18mM of caffeine. Three independant experiments were performed at each dose using different drosophila for each experiment.
2014-07-04 | E-GEOD-59084 | biostudies-arrayexpress
Project description:This study aimed to determine the effect of 3 mg.kg-1 acute caffeine ingestion on muscular strength, power and strength endurance and the repeatability of potential ergogenic effects across multiple trials. Twenty-two university standard male rugby union players (20 ± 2 years) completed the study. Using a double-blind, randomized, and counterbalanced within-subject experimental design. Participants completed six experimental trials (three caffeine and three placebo) where force time characteristic of the Isometric Mid-Thigh Pull (IMTP), Countermovement Jump (CMJ) and Drop Jumps (DJ) were assessed followed by assessments of Chest Press (CP), Shoulder Press (SP), Squats (SQ), and Deadlifts (DL) Repetitions Until Failure (RTF at 70% 1 RM). ANOVA indicated that caffeine improved both the CMJ and DJ (p < 0.044) and increased RTF in all RTF assessments (p < 0.002). When individual caffeine trials were compared to corresponding placebo trials, effect sizes ranged from trivial-large favoring caffeine irrespective of a main effect of treatment being identified in the ANOVA. These results demonstrate for the first time that the performance enhancing effects of caffeine may not be repeatable between days, where our data uniquely indicates that this is in part attributable to between sessions variation in caffeine's ergogenic potential.
| S-EPMC9611362 | biostudies-literature
Project description:BackgroundWhole blood is frequently utilized in genome-wide association studies of DNA methylation patterns in relation to environmental exposures or clinical outcomes. These associations can be confounded by cellular heterogeneity. Algorithms have been developed to measure or adjust for this heterogeneity, and some have been compared in the literature. However, with new methods available, it is unknown whether the findings will be consistent, if not which method(s) perform better.ResultsMethods: We compared eight cell-type correction methods including the method in the minfi R package, the method by Houseman et al., the Removing unwanted variation (RUV) approach, the methods in FaST-LMM-EWASher, ReFACTor, RefFreeEWAS, and RefFreeCellMix R programs, along with one approach utilizing surrogate variables (SVAs). We first evaluated the association of DNA methylation at each CpG across the whole genome with prenatal arsenic exposure levels and with cancer status, adjusted for estimated cell-type information obtained from different methods. We then compared CpGs showing statistical significance from different approaches. For the methods implemented in minfi and proposed by Houseman et al., we utilized homogeneous data with composition of some blood cells available and compared them with the estimated cell compositions. Finally, for methods not explicitly estimating cell compositions, we evaluated their performance using simulated DNA methylation data with a set of latent variables representing "cell types".ResultsResults from the SVA-based method overall showed the highest agreement with all other methods except for FaST-LMM-EWASher. Using homogeneous data, minfi provided better estimations on cell types compared to the originally proposed method by Houseman et al. Further simulation studies on methods free of reference data revealed that SVA provided good sensitivities and specificities, RefFreeCellMix in general produced high sensitivities but specificities tended to be low when confounding is present, and FaST-LMM-EWASher gave the lowest sensitivity but highest specificity.ConclusionsResults from real data and simulations indicated that SVA is recommended when the focus is on the identification of informative CpGs. When appropriate reference data are available, the method implemented in the minfi package is recommended. However, if no such reference data are available or if the focus is not on estimating cell proportions, the SVA method is suggested.
| S-EPMC5391562 | biostudies-literature
Project description:The buffering capacity of the soil is a very important property of the soil, which determines the ability of the soil to resist external influences, especially changes in pH and thus create good living conditions for plants and microorganisms in the soil. The buffering capacity thus significantly contributes to maintaining the health and quality of the soil. Buffering capacity is an important indicator of soil quality, because it is related to the overall condition of the soil ecosystem and other soil properties. The goal of this paper is to determine the effect of applying different soil amendments on the soils, 10 years after application. We compared the effect of 6 different treatments in closed plots: Natural conditions (N = control); Bare soil (B); Straw mulching (S); Pine mulch (P); TerraCottem hydroabsorbent polymers (H); Prescribed burn (F); and Sewage sludge (M). Our results have shown that the application of different amedments leads to an effect on the plowing capacity of the soil. While in the case of the control variant (Natural conditions, N) the buffering capacity of the soil was measured at 144.93 ± 0.25, the addition of different amendments decreased the buffering capacity in the following order: Bare soil (B) 142.73±0.21 > TerraCotem hydroaborbent polymer (H) 142.23±.15 > Pine mulch (P) 140.40±0.30, Prescribed burn (F) 138.20±0.30, Sludge (S) 127.47±0.15. In the case of all variants, these are statistically significant differences (p ≤ 0.05). Thus, soil amendments have been shown to have a statistically significant effect on soil buffering capacity.
| S-EPMC8827450 | biostudies-literature