Mouth exposure to carbohydrate prior to exercise possibly impairs the efficacy of carbohydrate mouth rinsing during exercise

Decker K. P., M. J. Saunders, N. D. Luden, C. J. Womack, and N. J. Hladick. Mouth Exposure to Carbohydrate Prior to Exercise Possibly Impairs the Efficacy of Carbohydrate Mouth Rinsing during Exercise. Purpose: Carbohydrate mouth-rinsing (CHO-MR) during intense endurance exercise has been associated with improved cycling performance, due to neurological influences. However, prior studies have reported the efficacy of CHO-MR is attenuated following a pre-exercise meal. To determine if this outcome is related to desensitization of CHO receptors (rather than metabolic effects following digestion), this study will investigate whether CHO-MR prior to exercise influences cycling performance when CHO-MR is also used during exercise. Methods: Eight trained cyclists (age, 24 ± 6 yr; height, 176 ± 6 cm; weight 75 ± 12 kg; VO2max, 61 ± 8 ml/kg/min) completed three exercise trials, each consisting of 15-min of incremental, constant-load exercise followed by a simulated 30-km time-trial (TT). Treatment beverages in the trials were randomly counterbalanced: a) PL_PL: placebo before and during exercise, b) PL_CHO: placebo pre-exercise, CHO-MR during exercise, and c) R_CHO: CHO-MR before and during exercise. Physiological responses (VO2, VE, RER, RPE, heart rate, blood glucose and lactate) were assessed during constant-load exercise and during the TT. Magnitude-based qualitative inferences were used to evaluate differences in responses between treatments. Results: TT performance was ‘possibly’ impaired (59% likelihood) with R_CHO (57.3 ± 3.6) versus PL_CHO (56.9 ± 3.0 min). Both trials were ‘likely’ slower than PL_PL (55.8 ± 3.1 min), but the reliability of performance data from this trial may have been impacted by measurement error, which limited our ability to determine the influence of CHO-MR during exercise. Physiological responses between treatments during constant-load cycling, and the TT were generally similar between all treatments. Conclusion: A pre-exercise CHO-MR had a possibly negative impact on cycling performance that also included CHO-MR during exercise. Although further evidence is required to validate this finding, our data suggests that desensitization of CHO receptors related to recent CHO exposure may be partially responsible for previous reports that the efficacy of CHO-MR during exercise are attenuated by pre-exercise feedings. Keywords: CYCLING, CARBOHYDRATE, MOUTH-RINSING, PERFORMANCE, ERGOGENIC-AIDS

Problems of Double Charm Production in e+e−e^+e^- Annihilation at s=10.6\sqrt{s}=10.6 GeV

Using the nonrelativistic QCD(NRQCD) factorization formalism, we calculate the color-singlet cross sections for exclusive production processes ${e^++e^-\to J/\psi+\eta_c}$~ and ~$e^++e^-\to J/\psi + \chi_{cJ}$~$(J=0,1,2)$ at the center-of-mass energy $\sqrt{s}$=10.6 GeV. The cross sections are estimated to be 5.5fb, 6.7fb, 1.1fb, and 1.6fb for $\eta_c, \chi_{c0}, \chi_{c1}$ and $\chi_{c2}$, respectively. The calculated $J/\psi+\eta_c$ production rate is smaller than the recent Belle data by about an order of magnitude, which might indicate the failure of perturbative QCD calculation to explain the double-charmonium production data. The complete $\cal{O}$$(\alpha^2_{s})$ color-singlet cross section for ${e^++e^-\to \chi_{c0}+ c\bar {c}}$ is calculated. In addition, we also evaluate the ratio of exclusive to inclusive production cross sections. The ratio of $J/\psi\eta_c$ production to $J/\psi c\bar{c}$ production could be consistent with the experimental data.Comment: 10 pages, 4 figures. A few references added, errors and typoes correcte

Effects of Simple Carbohydrate vs. Carbohydrate-Protein Intake on Glucose Homeostasis Following Intense Exercise

Kluka, J., Baskerville, J., Clifton, K., Fisher, K., Marks, D., Weidner, C., Veerabhadrappa, P. and Braun, W.A. (FACSM), Shippensburg University, Shippensburg, PA. Purpose: To test the effects of simple carbohydrate (CHO) and the combination of CHO and protein on blood glucose (BG) clearance following intense anaerobic exercise. Methods: Eight members (age = 18.8 ± 1.4 years) of the Shippensburg University Football team participated in the study. On separate test days, subjects were given either a placebo (PL) drink, a CHO drink (74 g CHO in 473 ml), or a carbohydrate-protein (C-PRO) drink (58 g CHO and 16 g PRO in 473 ml), upon completing the exercise bout. Before exercise, baseline measurements were taken for BG and heart rate. The subject then completed a 90-sec modified Wingate protocol (resistance set at 70% of the individual’s Wingate protocol resistance). BG was tested post-exercise, and every ten minutes after ingestion of the solution for 60 min. Results: Neither total revolutions completed (PL = 123.0±5.0; CHO = 126.9±3.9; C-PRO = 125.4±2.8) nor post-exercise BG (mg.dl-1) differed across treatments (PL = 88.6±6.5; CHO = 93.1±4.0; C-PRO = 101.1±4.7). However, CHO elicited the highest (p\u3c0.05) mean BG during recovery and the lowest BG was found in the PL. Conclusion: While matching post-exercise energy intake, C-PRO elicited a smaller BG area than CHO but tended to be larger than that of PL (p=0.052). C-PRO may be a better choice for post-exercise intake if aiming to maintain glucose homeostasis during recovery

Carbohydrate gel ingestion significantly improves the intermittent endurance capacity, but not sprint performance, of adolescent team games players during a simulated team games protocol

The aim of this study was to investigate the influence of ingesting a carbohydrate (CHO) gel on the intermittent endurance capacity and sprint performance of adolescent team games players. Eleven participants [mean age 13.5 ± 0.7 years, height 1.72 ± 0.08 m, body mass (BM) 62.1 ± 9.4 kg] performed two trials separated by 3–7 days. In each trial, they completed four 15 min periods of part A of the Loughborough Intermittent Shuttle Test (LIST), followed by an intermittent run to exhaustion (part B). In the 5 min pre-exercise, participants consumed 0.818 mL kg−1 BM of a CHO or a non-CHO placebo gel, and a further 0.327 mL kg−1 BM every 15 min during part A of the LIST (38.0 ± 5.5 g CHO h−1 in the CHO trial). Intermittent endurance capacity was increased by 21.1% during part B when the CHO gel was ingested (4.6 ± 2.0 vs. 3.8 ± 2.4 min, P < 0.05, r = 0.67), with distance covered in part B significantly greater in the CHO trial (787 ± 319 vs. 669 ± 424 m, P < 0.05, r = 0.57). Gel ingestion did not significantly influence mean 15 m sprint time (P = 0.34), peak sprint time (P = 0.81), or heart rate (P = 0.66). Ingestion of a CHO gel significantly increases the intermittent endurance capacity of adolescent team games players during a simulated team games protocol

Impact of pre-exercise feedings with a low or high glycemic index on the ergogenic effects of carbohydrate mouth-rinsing during cycling

Purpose: Carbohydrate (CHO) ingestion during exercise enhances performance in short endurance events (~ 1 hr) due to neural influences, as demonstrated by the efficacy of CHO mouth-rinsing during cycling. However, the magnitude of these neural effects may be blunted following pre-exercise CHO feedings. This study examined whether the glycemic index (GI) of a pre-exercise meal affected time-trial (TT) performance in cyclists using a CHO mouth-rinse during exercise. Methods: Eight cyclists (age: 24 ± 6 yr; VO2max: 61 ± 8 ml×kg-1×min-1) completed 4 exercise trials, consisting of 15 min of constant-load cycling followed by a simulated 30-km TT. Treatments were: a) L-CHO: low GI CHO beverage pre-exercise (1.5 g×kg-1 CHO, 120 min prior), CHO mouth rinsing during exercise (6.4% maltodextrin solution), b) H-CHO: high GI CHO beverage (1.5 g×kg-1 CHO) pre-exercise, CHO mouth rinsing during-exercise, c) PL-CHO: placebo beverage pre-exercise, CHO mouth rinsing during exercise, and d) PL-PL: placebo beverage pre-exercise, placebo mouth rinsing during exercise. Blood glucose was measured before beverage consumption and at 30 and 120 min following ingestion. Physiological measurements (VO2, VE, RER, HR, RPE, glucose, lactate, and gastrointestinal distress) were assessed during constant-load cycling and the TT. Magnitude-based qualitative inferences were used to assess differences in responses between trials. Results: Blood glucose differed among treatments 30 min post-feeding (H-CHO \u3e L-CHO \u3e PL-CHO = PL-PL), and was lower in H-CHO versus PL-CHO and PL-PL during subsequent exercise. Compared to PL-CHO, TT performance was faster in both L-CHO (-0.5 ± 0.8 min; “likely” beneficial) and H-CHO (-0.7 ± 0.7 min; “likely” beneficial), with no systematic differences between L-CHO and H-CHO. However, none of the 3 mouth rinse trials were clearly different from the PL-PL trial. Conclusions: When using a CHO mouth rinse during exercise, CHO ingestion 2 hr prior to cycling enhanced TT performance versus exercise in the fasted state. The GI of the pre-exercise feeding did not systematically affect TT performance in cyclists using a CHO mouth-rinse. However, the impact of these findings is confounded by the lack of performance differences versus a control trial without CHO before or during exercise

The influence of serial carbohydrate mouth rinsing on power output during a cycle sprint

The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO) mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD) age: 23.1 (3.0) years, height: 1.83 (0.07) m, body mass (BM): 86.3 (13.5) kg) completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin) solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA) solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg-1 BM resistance. Eight participants achieved a greater peak power output (PPO) in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2. 14 W·kg-1, p &lt; 0.05). Magnitude inference analysis reported a likely benefit (81% likelihood) of the CHO mouth rinse on PPO. In the CHO trial, mean power output (MPO) showed a trend for being greater in the first 5 seconds of the sprint and lower for the remainder of the sprint compared with the PLA trial (p &gt; 0.05). No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint

J/psi Production: Tevatron and Fixed-Target Collisions

In this talk I show the results of a fit of the NRQCD matrix elements to the CDF data for direct $J/\psi$ production, by including the radiative corrections to the colour-singlet channel and the effect of the $k_T$-smearing. Furthermore I perform the NLO NRQCD analysis of $J/\psi$ production in fixed-target proton-nucleon collisions and I fit the colour-octet matrix elements to the available experimental data. The results are compared to the Tevatron ones.Comment: 6 pages, 3 figures. Talk given at the QCD99 Euroconference, Montpellier, France, July 199

Complex organic molecules in comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy): detection of ethylene glycol and formamide

A spectral survey in the 1 mm wavelength range was undertaken in the long-period comets C/2012 F6 (Lemmon) and C/2013 R1 (Lovejoy) using the 30 m telescope of the Institut de radioastronomie millim\'etrique (IRAM) in April and November-December 2013. We report the detection of ethylene glycol (CH$_2$OH)$_2$ (aGg' conformer) and formamide (NH$_2$CHO) in the two comets. The abundances relative to water of ethylene glycol and formamide are 0.2-0.3% and 0.02% in the two comets, similar to the values measured in comet C/1995 O1 (Hale-Bopp). We also report the detection of HCOOH and CH$_3$CHO in comet C/2013 R1 (Lovejoy), and a search for other complex species (methyl formate, glycolaldehyde).Comment: Accepted for publication as a Letter in Astronomy and Astrophysic

The effect of caffeine mouth rinse on self-paced cycling performance

The aim of the study was to determine whether caffeine mouth rinse would improve 30 min self-paced cycling trial. Twelve healthy active males (age 20.5±0.7 years, mass 87.4±18.3 kg) volunteered for the study. They attended the laboratory on 3 separate occasions performing a 30 min self-paced cycling trial. On one occasion water was given as a mouth rinse for 5 s (PLA), on another occasion a 6.4% maltodextrin (CHO) solution was given for 5 s and finally a caffeine solution (containing 32 mg of caffeine dissolved in 125 ml water; CAF) was given for 5 s. Distance cycled, heart rate, ratings of perceived exertion, cadence, speed and power output were recorded throughout all trials. Distance cycled during the CAF mouth rinse trial (16.2±2.8 km) was significantly greater compared to PLA trial (14.9±2.6 km). There was no difference between CHO and CAF trials (P=0.89). Cadence, power and velocity were significantly greater during the CAF trial compared to both PLA and CHO (P0.05). Caffeine mouth rinse improves 30 min cycling performance by allowing the participant to increase cadence, power and velocity without a concurrent increase in perceived exertion and heart rate