Effect of 6% Maltodextrin Intake on Capillary Lactate Concentration in Soccer Players

Recent literature suggests that ergogenic substances may play a beneficial role in intermittent exercise. Maltodextrin supplementation has been investigated in soccer players, but few studies have been reported. The aim of this study was to evaluate the effect of 6% maltodextrin supplementation on capillary lactate in soccer players. The study was carried out during soccer training, which was characterised by intense activity (90 min). Participants (n = 24) were randomly allocated in control (water) and intervention (6% maltodextrin solution) groups. Capillary lactate levels were evaluated at pre-exercise (0 min—t0), exercise (45 min—t1), and post-exercise (90 min—t2) moments. At t1, the mean capillary lactate concentration value was significantly higher in players not supplemented with 6% maltodextrin (5.47 mmol/L) than in supplemented players (4.79 mmol/L).

Bingeing in rats: Persistence of high intakes of palatable solutions induced by 1-in-4 days intermittent access

When animals are given access to a palatable food or drink on some days but not on others, the amount they consume can far exceed the daily amounts consumed by controls given daily access. In a previous study such bingeing was found when rats were given 4% sucrose solution; it also found that, following 1-in-4-days access for many weeks, intakes remained persistently higher than that of controls even when the conditions were changed to 1-in-2-days access for both groups. One aim of the three experiments reported here was to test whether such persistent bingeing could be found for other solutions. This was confirmed in rats for a saccharin solution and a highly palatable saccharin-plus-glucose solution. However, when a maltodextrin solution was used, initial increased intakes produced by the 1-in-4-days schedule were not maintained when this was changed to a 1-in-2-days schedule. These results suggested that the hedonic value of a solution is more important than its caloric content in determining whether it will support persistent bingeing. A second aim was to test for evidence that the 1-in-4-days procedure induced an addiction to the target solution. No such evidence was found using multiple measures including instrumental responding and anxiety-like behavior on the elevated plus-maze for craving and withdrawal respectively.

On the spray pulsations of the effervescent atomizers

The presented paper focuses on the comparison of the two effervescent atomizer configurations—the outside-in-gas (OIG) and the outside-in-liquid (OIL). The comparison was based on the spray pulsation assessment by different methods. The atomizers were tested under the same operating conditions given by the constant injection pressure (0.14 MPa) and the gas to the liquid mass ratio (GLR) varying from 2.5 to 5%. The aqueous maltodextrin solution was used as the working liquid (μ = 60 and 146 mPa·s). We found that the time-averaging method does not provide sufficient spray quality description. Based on the cumulative distribution function (CDF) we found that the OIG atomizer generated the spray with non-uniform droplet size distribution at all investigated GLRs. Exceptionally large droplets were present even in the spray which appeared stable when was analyzed by the time-averaging method.

Carbohydrate Mouth Rinsing: Improved Neuromuscular Performance During Isokinetic Fatiguing Exercise

Purpose:To determine whether repeated carbohydrate (CHO) mouth rinsing would improve neuromuscular performance during high-intensity fatiguing contractions.Methods:Eighteen young men (age 26.1 ± 5.0 y, BMI 22.9 ± 1.9) performed 3 maximal voluntary isometric contractions (MVICPRE). Immediately after, they completed 10-second mouth rinse with 6.4% maltodextrin solution (MAL), 7.1% glucose solution (GLU), water (W), artificially sweetened solution (PLA), or a control trial with no rinse (CON) in a crossover protocol. Subjects performed 5 sets of 30 isokinetic fatiguing contractions at 180°/s, and an MVICPOST with their elbow flexors was performed after each mouth rinse. Mechanical and electromyographic (EMG) signals were recorded from the biceps brachii and parameters of interest analyzed.Results:When rinsing the mouth with a solution containing CHO, independently of the sweetness, isokinetic performance was enhanced as shown by the greater total work achieved in comparison with CON. The decay of torque and mean fiber-conduction velocity (MFCV) recorded at the end of the fatiguing task was lower when rinsing the mouth with GLU than with CON. The torque recorded during the MVICPOST was greater with CHO with respect to CON, and this was associated to a lower decay of MFCV.Conclusions:CHO mouth rinse counteracts fatigue-induced decline in neuromuscular performance, supporting the notion that CHO rinse may activate positive afferent signals able to modify motor output. Repeated mouth rinsing with sweet and nonsweet CHO-containing solutions can improve neuromuscular performance during an isokinetic intermittent fatiguing task.

No Dose Response Effect of Carbohydrate Mouth Rinse on Cycling Time-Trial Performance

The aim of the current study was to investigate the influence of mouth rinsing carbohydrate at increasing concentrations on ~1 hr cycle time trial performance. Eleven male cyclists completed three experimental trials, following an overnight fast. Cyclists performed a ~1 hr time trial on a cycle ergometer, while rinsing their mouth for 5 s with either a 7% maltodextrin solution (CHO), 14% CHO or a taste-matched placebo (PLA) after every 12.5% of the set amount of work. Heart rate was recorded every 12.5% of the time trial, while RPE and GI comfort were determined every 25% of the time trial. The mouth rinse protocol influenced the time to complete the time trial (p < .001), with cyclists completing the time trial faster during 7% CHO (57.3 ± 4.5 min; p = .004) and 14% CHO (57.4 ± 4.1 min; p = .007), compared with PLA (59.5 ± 4.9 min). There was no difference between the two carbohydrate trials (p = .737). There was a main effect of time (P<0.001) for both heart rate and RPE, but no main effect of trial (p = .107 and p = .849, respectively). Scores for GI comfort ranged from 0–2 during trials, indicating very little GI discomfort during exercise. In conclusion, mouth rinsing and expectorating a 7% maltodextrin solution, for 5 s routinely during exercise was associated with improved cycle time trial performance approximately 1 h in duration. Increasing the carbohydrate concentration of the rinsed solution from 7% to 14% resulted in no further performance improvement.

The Influence of Carbohydrate Mouth Rinse on Self-Selected Intermittent Running Performance

This study investigated the influence of mouth rinsing a carbohydrate solution on self-selected intermittent variable-speed running performance. Eleven male amateur soccer players completed a modified version of the Loughborough Intermittent Shuttle Test (LIST) on 2 occasions separated by 1 wk. The modified LIST allowed the self-selection of running speeds during Block 6 of the protocol (75–90 min). Players rinsed and expectorated 25 ml of noncaloric placebo (PLA) or 10% maltodextrin solution (CHO) for 10 s, routinely during Block 6 of the LIST. Self-selected speeds during the walk and cruise phases of the LIST were similar between trials. Jogging speed was significantly faster during the CHO (11.3 ± 0.7 km·h−1) than during the PLA trial (10.5 ± 1.3 km · h−1) (p = .010); 15-m sprint speeds were not different between trials (PLA: 2.69 ± 0.18 s: CHO: 2.65 ± 0.13 s) (F(2, 10), p = .157), but significant benefits were observed for sprint distance covered (p = .024). The threshold for the smallest worthwhile change in sprint performance was set at 0.2 s. Inferential statistical analysis showed the chance that CHO mouth rinse was beneficial, negligible, or detrimental to repeated sprint performance was 86%, 10%, and 4%, respectively. In conclusion, mouth rinsing and expectorating a 10% maltodextrin solution was associated with a significant increase in self-selected jogging speed. Repeated 15-m sprint performance was also 86% likely to benefit from routinely mouth rinsing a carbohydrate solution in comparison with a taste-matched placebo.

The effects of carbohydrate ingestion on 30 minute rowing time trial performance

The aim of the study was to determine whether ingestion of 6.4% carbohydrate solution prior to 30 min rowing had any effect on distance rowed. Twelve male participants (aged 22.21±2.47 years) volunteered to take part. Participants ingested either 500 ml of 6.4% flavourless maltodextrin solution (CHO) or water (PLA) prior to exercise. During 30 min of self-paced rowing heart rate (HR), ratings of perceived exertion (RPE), stroke rate, power output and distance covered were recorded every 6-min throughout. Participants rowed significantly (P<0.05) further during the CHO trial (6,714.2±409.9 m) compared to the PLA trial (6,390.8±448.1 m). Power also increased during the CHO trial compared to the PLA (P<0.05). However, there was no difference in RPE. In conclusion, from the current investigation rowers who wish to improve their time trial performance in longer duration events may benefit from the ingestion of CHO prior to competition.