scholarly journals Carbohydrate Mouth Rinse Effects on Exercise Capacity in Pre- and Postprandial States

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Elie-J. M. Fares ◽  
Bengt Kayser
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Cycle Ergometer ◽  
Time To Exhaustion ◽  
Endurance Capacity ◽  
Maximal Heart Rate ◽  
Trained Subjects ◽  
Mouth Rinses ◽  
Mouth Rinsing ◽  
The Brain

Background. Oropharyngeal receptors signal presence of carbohydrate to the brain. Mouth rinses with a carbohydrate solution facilitate corticomotor output and improve time-trial performance in well-trained subjects in a fasted state. We tested for this effect in nonathletic subjects in fasted and nonfasted state.Methods. 13 healthy non-athletic males performed 5 tests on a cycle ergometer. After measuring maximum power output (Wmax), the subjects cycled four times at 60% Wmax until exhaustion while rinsing their mouth every 5 minutes with either a 6.4% maltodextrin solution or water, one time after an overnight fast and another after a carbohydrate rich breakfast.Results. Mouth rinsing with maltodextrin improved time-to-exhaustion in pre- and postprandial states. This was accompanied by reductions in the average and maximal rates of perceived exertion but no change in average or maximal heart rate was observed.Conclusions. Carbohydrate mouth rinsing improves endurance capacity in both fed and fasted states in non-athletic subjects.

Beneficial Effects of Ice Ingestion as a Precooling Strategy on 40-km Cycling Time-Trial Performance

2010 ◽  
Vol 5 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Mohammed Ihsan ◽  
Grant Landers ◽  
Matthew Brearley ◽  
Peter Peeling
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Tap Water ◽  
Time Trial ◽  
Cycle Ergometer ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Crushed Ice ◽  
Cycling Time ◽  
Trial Performance

Purpose:The effect of crushed ice ingestion as a precooling method on 40-km cycling time trial (CTT) performance was investigated.Methods:Seven trained male subjects underwent a familiarization trial and two experimental CTT which were preceded by 30 min of either crushed ice ingestion (ICE) or tap water (CON) consumption amounting to 6.8 g⋅kg-1 body mass. The CTT required athletes to complete 1200 kJ of work on a wind-braked cycle ergometer. During the CTT, gastrointestinal (Tgi) and skin (Tsk) temperatures, cycling time, power output, heart rate (HR), blood lactate (BLa), ratings of perceived exertion (RPE) and thermal sensation (RPTS) were measured at set intervals of work.Results:Precooling lowered the Tgi after ICE significantly more than CON (36.74 ± 0.67°C vs 37.27 ± 0.24°C, P < .05). This difference remained evident until 200 kJ of work was completed on the bike (37.43 ± 0.42°C vs 37.64 ± 0.21°C). No significant differences existed between conditions at any time point for Tsk, RPE or HR (P > .05). The CTT completion time was 6.5% faster in ICE when compared with CON (ICE: 5011 ± 810 s, CON: 5359 ± 820 s, P < .05).Conclusions:Crushed ice ingestion was effective in lowering Tgi and improving subsequent 40-km cycling time trial performance. The mechanisms for this enhanced exercise performance remain to be clarified.

scholarly journals Altered brain structure with preserved cortical motor activity after exertional hypohydration: a MRI study

2019 ◽  
Vol 127 (1) ◽  
pp. 157-167 ◽  
Author(s):  
X. R. Tan ◽  
I. C. C. Low ◽  
M. C. Stephenson ◽  
T. Kok ◽  
H. W. Nolte ◽  
...  
Keyword(s):  
Body Mass ◽  
Brain Structure ◽  
Functional Activity ◽  
Cerebral Perfusion ◽  
Primary Motor Cortex ◽  
Critical Role ◽  
Hydration Status ◽  
Time To Exhaustion ◽  
Endurance Capacity ◽  
The Brain

Hypohydration exceeding 2% body mass can impair endurance capacity. It is postulated that the brain could be perturbed by hypohydration, leading to impaired motor performance. We investigated the neural effects of hypohydration with magnetic resonance imaging (MRI). Ten men were dehydrated to approximately −3% body mass by running on a treadmill at 65% maximal oxygen consumption (V̇o2max) before drinking to replace either 100% [euhydration (EU)] or 0% [hypohydration (HH)] of fluid losses. MRI was performed before start of trial (baseline) and after rehydration phase (post) to evaluate brain structure, cerebral perfusion, and functional activity. Endurance capacity assessed with a time-to-exhaustion run at 75% V̇o2max was reduced with hypohydration (EU: 45.2 ± 9.3 min, HH: 38.4 ± 10.7 min; P = 0.033). Mean heart rates were comparable between trials (EU: 162 ± 5 beats/min, HH: 162 ± 4 beats/min; P = 0.605), but the rate of rise in rectal temperature was higher in HH trials (EU: 0.06 ± 0.01°C/min, HH: 0.07 ± 0.02°C/min; P < 0.01). In HH trials, a reduction in total brain volume (EU: +0.7 ± 0.6%, HH: −0.7 ± 0.9%) with expansion of ventricles (EU: −2.7 ± 1.6%, HH: +3.7 ± 3.3%) was observed, and vice versa in EU trials. Global and regional cerebral perfusion remained unchanged between conditions. Functional activation in the primary motor cortex in left hemisphere during a plantar-flexion task was similar between conditions (EU: +0.10 ± 1.30%, HH: −0.11 ± 0.31%; P = 0.637). Our findings demonstrate that with exertional hypohydration, brain volumes were altered but the motor-related functional activity was unperturbed. NEW & NOTEWORTHY Dehydration occurs rapidly during prolonged or intensive physical activity, leading to hypohydration if fluid replenishment is insufficient to replace sweat losses. Altered hydration status poses an osmotic challenge for the brain, leading to transient fluctuations in brain tissue and ventricle volumes. Therefore, the amount of fluid ingestion during exercise plays a critical role in preserving the integrity of brain architecture. These structural changes, however, did not translate directly to motor functional deficits in a simple motor task.

Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance

2013 ◽  
Vol 38 (6) ◽  
pp. 633-637 ◽  
Author(s):  
C. Martyn Beaven ◽  
Peter Maulder ◽  
Adrian Pooley ◽  
Liam Kilduff ◽  
Christian Cook
Keyword(s):  
Exercise Performance ◽  
Perceived Exertion ◽  
Power Production ◽  
Sprint Performance ◽  
Maximal Heart Rate ◽  
Mouth Rinse ◽  
Mean Power ◽  
Positive Effects ◽  
Repeated Sprint ◽  
Mouth Rinses

Our purpose was to examine the effectiveness of carbohydrate and caffeine mouth rinses in enhancing repeated sprint ability. Previously, studies have shown that a carbohydrate mouth rinse (without ingestion) has beneficial effects on endurance performance that are related to changes in brain activity. Caffeine ingestion has also demonstrated positive effects on sprint performance. However, the effects of carbohydrate or caffeine mouth rinses on intermittent sprints have not been examined previously. Twelve males performed 5 × 6-s sprints interspersed with 24 s of active recovery on a cycle ergometer. Twenty-five milliliters of either a noncaloric placebo, a 6% glucose, or a 1.2% caffeine solution was rinsed in the mouth for 5 s prior to each sprint in a double-blinded and balanced cross-over design. Postexercise maximal heart rate and perceived exertion were recorded, along with power measures. A second experiment compared a combined caffeine-carbohydrate rinse with carbohydrate only. Compared with the placebo mouth rinse, carbohydrate substantially increased peak power in sprint 1 (22.1 ± 19.5 W; Cohen's effect size (ES), 0.81), and both caffeine (26.9 ± 26.9 W; ES, 0.71) and carbohydrate (39.1 ± 25.8 W; ES, 1.08) improved mean power in sprint 1. Experiment 2 demonstrated that a combination of caffeine and carbohydrate improved sprint 1 power production compared with carbohydrate alone (36.0 ± 37.3 W; ES, 0.81). We conclude that carbohydrate and (or) caffeine mouth rinses may rapidly enhance power production, which could have benefits for specific short sprint exercise performance. The ability of a mouth-rinse intervention to rapidly improve maximal exercise performance in the absence of fatigue suggests a central mechanism.

Carbohydrate Mouth Rinsing in the Fed State: Lack of Enhancement of Time-Trial Performance

2009 ◽  
Vol 19 (4) ◽  
pp. 400-409 ◽  
Author(s):  
Milou Beelen ◽  
Jort Berghuis ◽  
Ben Bonaparte ◽  
Sam B. Ballak ◽  
Asker E. Jeukendrup ◽  
...  
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Perceived Exertion ◽  
Average Power ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Time Trial Performance ◽  
Mouth Rinsing ◽  
The Impact ◽  
Trial Performance

It has been reported previously that mouth rinsing with a carbohydrate-containing solution can improve cycling performance. The purpose of the current study was to investigate the impact of such a carbohydrate mouth rinse on exercise performance during a simulated time trial in a more practical, postprandial setting. Fourteen male endurance-trained athletes were selected to perform 2 exercise tests in the morning after consuming a standardized breakfast. They performed an ~1-hr time trial on a cycle ergometer while rinsing their mouths with either a 6.4% maltodextrin solution (CHO) or water (PLA) after every 12.5% of the set amount of work. Borg’s rating of perceived exertion (RPE) was assessed after every 25% of the set amount of work, and power output and heart rate were recorded continuously throughout the test. Performance time did not differ between treatments and averaged 68.14 ± 1.14 and 67.52 ± 1.00 min in CHO and PLA, respectively (p = .57). In accordance, average power output (265 ± 5 vs. 266 ± 5 W, p = .58), heart rate (169 ± 2 vs. 168 ± 2 beats/min, p = .43), and RPE (16.4 ± 0.3 vs. 16.7 ± 0.3 W, p = .26) did not differ between treatments. Furthermore, after dividing the trial into 8s, no differences in power output, heart rate, or perceived exertion were observed over time between treatments. Carbohydrate mouth rinsing does not improve time-trial performance when exercise is performed in a practical, postprandial setting.

Neurohumoral responses during prolonged exercise in humans

2003 ◽  
Vol 95 (3) ◽  
pp. 1125-1131 ◽  
Author(s):  
Lars Nybo ◽  
Bodil Nielsen ◽  
Eva Blomstrand ◽  
Kirsten Møller ◽  
Niels Secher
Keyword(s):  
Perceived Exertion ◽  
Prolonged Exercise ◽  
Strenuous Exercise ◽  
Trained Subjects ◽  
Perception Of Effort ◽  
Arteriovenous Difference ◽  
The Brain ◽  
Oxygen Difference ◽  
Net Release ◽  
Exercise In Humans

This study examined neurohumoral alterations during prolonged exercise with and without hyperthermia. The cerebral oxygen-to-carbohydrate uptake ratio (O2/CHO = arteriovenous oxygen difference divided by arteriovenous glucose difference plus one-half lactate), the cerebral balances of dopamine, and the metabolic precursor of serotonin, tryptophan, were evaluated in eight endurance-trained subjects during exercise randomized to be with or without hyperthermia. The core temperature stabilized at 37.9 ± 0.1°C (mean ± SE) in the control trial, whereas it increased to 39.7 ± 0.2°C in the hyperthermic trial, with a concomitant increase in perceived exertion ( P < 0.05). At rest, the brain had a small release of tryptophan (arteriovenous difference of -1.2 ± 0.3 μmol/l), whereas a net balance was obtained during the two exercise trials. Both the arterial and jugular venous dopamine levels became elevated during the hyperthermic trial, but the net release from the brain was unchanged. During exercise, the O2/CHO was similar across trials, but, during recovery from the hyperthermic trial, the ratio decreased to 3.8 ± 0.3 ( P < 0.05), whereas it returned to the baseline level of ∼6 within 5 min after the control trial. The lowering of O2/CHO was established by an increased arteriovenous glucose difference (1.1 ± 0.1 mmol/l during recovery from hyperthermia vs. 0.7 ± 0.1 mmol/l in control; P < 0.05). The present findings indicate that the brain has an increased need for carbohydrates during recovery from strenuous exercise, whereas enhanced perception of effort as observed during exercise with hyperthermia was not related to alterations in the cerebral balances of dopamine or tryptophan.

scholarly journals Running Performance With Nutritive and Nonnutritive Sweetened Mouth Rinses

2017 ◽  
Vol 12 (8) ◽  
pp. 1105-1110 ◽  
Author(s):  
Keely R. Hawkins ◽  
Sridevi Krishnan ◽  
Lara Ringos ◽  
Vanessa Garcia ◽  
Jamie A. Cooper
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Endurance Performance ◽  
Sweet Taste ◽  
Artificial Sweetener ◽  
Ratings Of Perceived Exertion ◽  
Treatment Conditions ◽  
Mouth Rinses ◽  
Blinded Study ◽  
Sweetness Intensity

Using mouth rinse (MR) with carbohydrate during exercise has been shown to act as an ergogenic aid.Purpose:To investigate if nutritive or nonnutritive sweetened MR affects exercise performance and to assess the influence of sweetness intensity on endurance performance during a time trial (TT).Methods:This randomized, single-blinded study had 4 treatment conditions. Sixteen subjects (9 men, 7 women) completed a 12.8-km TT 4 different times. During each TT, subjects mouth-rinsed and expectorated a different solution at time 0 and every 12.5% of the TT. The 4 MR solutions were sucrose (S) (sweet taste and provides energy of 4 kcal/g), a lower-intensity sucralose (S1:1) (artificial sweetener that provides no energy but tastes sweet), a higher-intensity sucralose (S100:1), and water as control (C). Completion times for each TT, heart rate (HR), and ratings of perceived exertion (RPE) were also recorded.Results:Completion time for S was faster than for C (1:03:47 ± 00:02:17 vs 1:06:56 ± 00:02:18, respectively; P < .001) and showed a trend to be faster vs S100:1 (1:03:47 ± 00:02:17 vs 1:05:38 ± 00:02:12, respectively; P = .07). No other TT differences were found. Average HR showed a trend to be higher for S vs C (P = .08). The only difference in average or maximum RPE was for higher maximum RPE in C vs S1:1 (P = .02).Conclusion:A sweet-tasting MR did improve endurance performance compared with water in a significant manner (mean 4.5% improvement; 3+ min.); however, the presence of energy in the sweet MR appeared necessary since the artificial sweeteners did not improve performance more than water alone.

scholarly journals The effects of head cooling on endurance and neuroendocrine responses to exercise in warm conditions

2008 ◽  
pp. 863-872
Author(s):  
L Ansley ◽  
G Marvin ◽  
A Sharma ◽  
MJ Kendall ◽  
DA Jones ◽  
...  
Keyword(s):  
Rectal Temperature ◽  
Perceived Exertion ◽  
Cycle Ergometer ◽  
Tympanic Temperature ◽  
Head Cooling ◽  
Exercise Period ◽  
Volitional Fatigue ◽  
Prolactin Response ◽  
Response To Exercise ◽  
The Brain

The present study investigated the effects of head cooling during endurance cycling on performance and the serotonergic neuroendocrine response to exercise in the heat. Subjects exercised at 75 % VO2max to volitional fatigue on a cycle ergometer at an ambient temperature of 29±1.0 °C, with a relative humidity of approximately 50 %. Head cooling resulted in a 51 % (p<0.01) improvement in exercise time to fatigue and Borg Scale ratings of perceived exertion were significantly lower throughout the exercise period with cooling (p<0.01). There were no indications of peripheral mechanisms of fatigue either with, or without, head cooling, indicating the importance of central mechanisms. Exercise in the heat caused the release of prolactin in response to the rise in rectal temperature. Head cooling largely abolished the prolactin response while having no effect on rectal temperature. Tympanic temperature and sinus skin temperature were reduced by head cooling and remained low throughout the exercise. It is suggested that there is a coordinated response to exercise involving thermoregulation, neuroendocrine secretion and behavioural adaptations that may originate in the hypothalamus or associated areas of the brain. Our results are consistent with the effects of head cooling being mediated by both direct cooling of the brain and modified cerebral artery blood flow, but an action of peripheral thermoreceptors cannot be excluded.

Breaking Away: Effects of Nonuniform Pacing on Power Output and Growth of Rating of Perceived Exertion

2013 ◽  
Vol 8 (4) ◽  
pp. 352-357 ◽  
Author(s):  
Jacob Cohen ◽  
Bridgette Reiner ◽  
Carl Foster ◽  
Jos J. de Koning ◽  
Glenn Wright ◽  
...  
Keyword(s):  
Power Output ◽  
Cycle Time ◽  
Growth Pattern ◽  
Perceived Exertion ◽  
Time Trial ◽  
Normal Growth ◽  
Reciprocal Relationship ◽  
The Body ◽  
Rating Of Perceived Exertion ◽  
The Brain

The rating of perceived exertion (RPE) normally grows as a scalar function of relative competitive distance, suggesting that it may translate between the brain and body relative to managing fatigue during time-trial exercise. In nonstandard pacing situations, a reciprocal relationship between RPE and power output (PO) would be predicted.Purpose:To determine whether PO would decrease when RPE was forced above the normal growth curve during a cycle time trial.Methods:Well-trained cyclists performed randomly ordered 10-km cycle time trials. In CONTROL they rode at their own best pace throughout. In BURST, they made a 1-km “burst” at the 4-km mark and then finished as rapidly as possible.Results:CONTROL was significantly (P < .05) faster than BURST (16:36 vs 17:00 min). During CONTROL, responses between 4 and 5 km were PO, 240 W; RPE, 5–6; and blood lactate [HLa], 8–9 mmol/L. During BURST PO increased to 282 W, then fell to 220 W after the burst and remained below CONTROL until the end spurt (9 km). RPE increased to 9 during the burst but returned to the normal RPE growth pattern by 6 km; [HLa] increased to ~13 mmol/L after the burst and remained elevated throughout the remainder of the trial.Conclusions:The reciprocal behavior of RPE and PO after BURST supports the hypothesis that RPE translates between the brain and the body during heavy exercise. However, the continuing reduction of PO after the burst, even after RPE returned to its normal growth pattern, suggests that PO is regulated in a more complex manner than reflected solely by RPE.

The Effects of Preexercise Caffeinated Coffee Ingestion on Endurance Performance: An Evidence-Based Review

2016 ◽  
Vol 26 (3) ◽  
pp. 221-239 ◽  
Author(s):  
Simon Higgins ◽  
Chad R. Straight ◽  
Richard D. Lewis
Keyword(s):  
Perceived Exertion ◽  
Human Subjects ◽  
Time Trial ◽  
Endurance Performance ◽  
Ergogenic Aid ◽  
Time To Exhaustion ◽  
Evidence Based ◽  
Safe Alternative ◽  
Usable Information ◽  
Caffeinated Coffee

Endurance athletes commonly ingest caffeine as a means to enhance training intensity and competitive performance. A widely-used source of caffeine is coffee, however conflicting evidence exists regarding the efficacy of coffee in improving endurance performance. In this context, the aims of this evidence-based review were threefold: 1) to evaluate the effects of preexercise coffee on endurance performance, 2) to evaluate the effects of coffee on perceived exertion during endurance performance, and 3) to translate the research into usable information for athletes to make an informed decision regarding the intake of caffeine via coffee as a potential ergogenic aid. Searches of three major databases were performed using terms caffeine and coffee, or coffee-caffeine, and endurance, or aerobic. Included studies (n = 9) evaluated the effects of caffeinated coffee on human subjects, provided the caffeine dose administered, administered caffeine ≥ 45 min before testing, and included a measure of endurance performance (e.g., time trial). Significant improvements in endurance performance were observed in five of nine studies, which were on average 24.2% over controls for time to exhaustion trials, and 3.1% for time to completion trials. Three of six studies found that coffee reduced perceived exertion during performance measures significantly more than control conditions (p < .05). Based on the reviewed studies there is moderate evidence supporting the use of coffee as an ergogenic aid to improve performance in endurance cycling and running. Coffee providing 3–8.1 mg/kg (1.36–3.68 mg/lb) of caffeine may be used as a safe alternative to anhydrous caffeine to improve endurance performance.

scholarly journals The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chloe Gao ◽  
Saurabh Gupta ◽  
Taranah Adli ◽  
Winston Hou ◽  
Reid Coolsaet ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Cochrane Collaboration ◽  
Performance Measure ◽  
Time To Exhaustion ◽  
Cochrane Central Register ◽  
Endurance Sports ◽  
Dietary Nitrate ◽  
Significant Difference ◽  
Nitrate Supplementation

Abstract Background Nitrate supplementation is thought to improve performance in endurance sports. Objective To meta-analyze studies evaluating the effect of nitrate supplementation on endurance sports performance among adults. Data sources We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science and CINAHL without language restrictions. Methods We included studies that: 1) compared nitrate supplementation with placebo; 2) enrolled adults engaging in an endurance-based activity; and 3) reported a performance measure or surrogate physiologic outcome. We evaluated risk of bias using the Cochrane Collaboration tool and pooled data with a random-effects model. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to evaluate confidence in estimates. Results We included 73 studies (n = 1061). Nitrate supplementation improved power output (MD 4.6 watts, P < 0.0001), time to exhaustion (MD 25.3 s, P < 0.00001), and distance travelled (MD 163.7 m, P = 0.03). We found no significant difference on perceived exertion, time trial performance and work done. Nitrate supplementation decreased VO2 (MD − 0.04 L/min, P < 0.00001) but had no significant effect on VO2max or blood lactate levels. Conclusion The available evidence suggests that dietary nitrate supplementation benefits performance-related outcomes for endurance sports.

Sign in / Sign up

Export Citation Format

Share Document