scholarly journals Coconut Water Does Not Improve Markers of Hydration During Sub-maximal Exercise and Performance in a Subsequent Time Trial Compared with Water Alone

2017 ◽  
Vol 27 (3) ◽  
pp. 279-284 ◽  
Author(s):  
Daniel J. Peart ◽  
Andy Hensby ◽  
Matthew P. Shaw
Keyword(s):  
Body Mass ◽  
Perceived Exertion ◽  
Time Trial ◽  
Urine Osmolality ◽  
Coconut Water ◽  
Time Trial Performance ◽  
Physiological Variables ◽  
Subsequent Time ◽  
Voluntary Intake ◽  
Trial Performance

The purpose of this study was to compare markers of hydration during submaximal exercise and subsequent time trial performance when consuming water (PW) or coconut water (CW). There was also a secondary aim to assess the palatability of CW during exercise and voluntary intake during intense exercise. 10 males (age 27.9 ± 4.9 years, body mass 78.1 ± 10.1kg, average max minute power 300.2 ± 28.2W) completed 60-min of submaximal cycling followed by a 10-km time trial on two occasions. During these trials participants consumed either PW or CW in a randomized manner, drinking a 250 ml of the assigned drink between 10–15 min, 25–30 min and 40–45 min, and then drinking ad libitum from 55-min until the end of the time trial. Body mass and urine osmolality were recorded preexercise and then after 30-min, 60-min, and post time trial. Blood glucose, lactate, heart rate, rate of perceived exertion (RPE; 6–20) and ratings of thirst, sweetness, nausea, fullness and stomach upset (1 =very low/none, 5= very high) were recorded during each drink period. CW did not significantly improve time trial performance compared with PW (971.4 ± 50.5 and 966.6 ± 44.8 s respectively; p = .698) and there was also no significant differences between trials for any of the physiological variables measured. However there were subjective differences between the beverages for taste, resulting in a significantly reduced volume of voluntary intake in the CW trial (115 ± 95.41 ml and 208.7 ± 86.22 ml; p < .001).

scholarly journals Effect of Thirst-Driven Fluid Intake on 1 H Cycling Time-Trial Performance in Trained Endurance Athletes

Sports ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 223
Author(s):  
Maxime Perreault-Briere ◽  
Jeff Beliveau ◽  
David Jeker ◽  
Thomas A. Deshayes ◽  
Ana Duran ◽  
...  
Keyword(s):  
Body Mass ◽  
Perceived Exertion ◽  
Fluid Intake ◽  
Time Trial ◽  
Endurance Athletes ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
The Impact ◽  
Cycling Time ◽  
Trial Performance

A meta-analysis demonstrated that programmed fluid intake (PFI) aimed at fully replacing sweat losses during a 1 h high-intensity cycling exercise impairs performance compared with no fluid intake (NFI). It was reported that thirst-driven fluid intake (TDFI) may optimize cycling performance, compared with when fluid is consumed more than thirst dictates. However, how TDFI, compared with PFI and NFI, impacts performance during a 1 h cycling time-trial performance remains unknown. The aim of this study was to compare the effect of NFI, TDFI and PFI on 1 h cycling time-trial performance. Using a randomized, crossover and counterbalanced protocol, 9 (7 males and 2 females) trained endurance athletes (30 ± 9 years; Peak V · O2∶ 59 ± 8 mL·kg−1·min−1) completed three 1 h cycling time-trials (30 °C, 50% RH) with either NFI, TDFI or PFI designed to maintain body mass (BM) at ~0.5% of pre-exercise BM. Body mass loss reached 2.9 ± 0.4, 2.2 ± 0.3 and 0.6 ± 0.2% with NFI, TDFI and PFI, respectively. Heart rate, rectal and mean skin temperatures and ratings of perceived exertion and of abdominal discomfort diverged marginally among trials. Mean distance completed (NFI: 35.6 ± 1.9 km; TDFI: 35.8 ± 2.0; PFI: 35.7 ± 2.0) and, hence, average power output maintained during the time-trials did not significantly differ among trials, and the impact of both PFI and TDFI vs. NFI was deemed trivial or unclear. These findings indicate that neither PFI nor TDFI are likely to offer any advantage over NFI during a 1 h cycling time-trial.

scholarly journals Blinded and unblinded hypohydration similarly impair cycling time trial performance in the heat in trained cyclists

2019 ◽  
Vol 126 (4) ◽  
pp. 870-879 ◽  
Author(s):  
Mark P. Funnell ◽  
Stephen A. Mears ◽  
Kurt Bergin-Taylor ◽  
Lewis J. James
Keyword(s):  
Body Mass ◽  
Perceived Exertion ◽  
Time Trial ◽  
Cycling Performance ◽  
Rating Of Perceived Exertion ◽  
Hydration Status ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
The Many ◽  
Trial Performance

Knowledge of hydration status may contribute to hypohydration-induced exercise performance decrements; therefore, this study compared blinded and unblinded hypohydration on cycling performance. Fourteen trained, nonheat-acclimated cyclists (age: 25 ± 5 yr; V̇o2peak: 63.3 ± 4.7 ml·kg−1·min−1; cycling experience: 6 ± 3 yr) were pair matched to blinded (B) or unblinded (UB) groups. After familiarization, subjects completed euhydrated (B-EUH; UB-EUH) and hypohydrated (B-HYP; UB-HYP) trials in the heat (31°C); 120-min cycling preload (50% Wpeak) and a time trial (~15 min). During the preload of all trials, 0.2 ml water·kg body mass−1 was ingested every 10 min, with additional water provided during EUH trials to match sweat losses. To blind the B group, a nasogastric tube was inserted in both trials and used to provide water in B-EUH. The preload induced similar ( P = 0.895) changes in body mass between groups (B-EUH: −0.6 ± 0.5%; B-HYP: −3.0 ± 0.5%; UB-EUH: −0.5 ± 0.3%; UB-HYP −3.0 ± 0.3%). All variables responded similarly between B and UB groups ( P ≥ 0.558), except thirst ( P = 0.004). Changes typical of hypohydration (increased heart rate, rating of perceived exertion, gastrointestinal temperature, serum osmolality and thirst, and decreased plasma volume; P ≤ 0.017) were apparent in HYP by 120 min. Time trial performance was similar between groups ( P = 0.710) and slower ( P ≤ 0.013) with HYP for B (B-EUH: 903 ± 89 s; B-HYP: 1,008 ± 121 s; −11.4%) and UB (UB-EUH: 874 ± 108 s; UB-HYP: 967 ± 170 s; −10.1%). Hypohydration of ~3% body mass impairs time trial performance in the heat, regardless of knowledge of hydration status. NEW & NOTEWORTHY This study demonstrates, for the first time, that knowledge of hydration status does not exacerbate the negative performance consequences of hypohydration when hypohydration is equivalent to ~3% body mass. This is pivotal for the interpretation of the many previous studies that have not blinded subjects to their hydration status and suggests that these previous studies are not likely to be confounded by the overtness of the methods used to induce hypohydration.

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.

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.

Effects of Varying Post-Warm-Up Recovery Time on 200-m Time-Trial Swim Performance

2007 ◽  
Vol 2 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Thomas Zochowski ◽  
Elizabeth Johnson ◽  
Gordon G. Sleivert
Keyword(s):  
Heart Rate ◽  
Blood Lactate ◽  
Recovery Time ◽  
Perceived Exertion ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Warm Up ◽  
Swimming Time ◽  
Time Trial Performance ◽  
Trial Performance

Context:Warm-up before athletic competition might enhance performance by affecting various physiological parameters. There are few quantitative data available on physiological responses to the warm-up, and the data that have been reported are inconclusive. Similarly, it has been suggested that varying the recovery period after a standardized warm-up might affect subsequent performance.Purpose:To determine the effects of varying post-warm-up recovery time on a subsequent 200-m swimming time trial.Methods:Ten national-caliber swimmers (5 male, 5 female) each swam a 1500-m warm-up and performed a 200-m time trial of their specialty stroke after either 10 or 45 min of passive recovery. Subjects completed 1 time trial in each condition separated by 1 wk in a counterbalanced order. Blood lactate and heart rate were measured immediately after warm-up and 3 min before, immediately after, and 3 min after the time trial. Rating of perceived exertion was measured immediately after the warm-up and time trial.Results:Time-trial performance was significantly improved after 10 min as opposed to 45 min recovery (136.80 ± 20.38 s vs 138.69 ± 20.32 s, P < .05). There were no significant differences between conditions for heart rate and blood lactate after the warm-up. Pre-time-trial heart rate, however, was higher in the 10-min than in the 45-min rest condition (109 ± 14 beats/min vs 94 ± 21 beats/min, P < .05).Conclusions:A post-warm-up recovery time of 10 min rather than 45 min is more beneficial to 200-m swimming time-trial performance.

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

2014 ◽  
Vol 10 (4) ◽  
pp. 247-252
Author(s):  
L. Bottoms ◽  
R. Westhead ◽  
J. Evans ◽  
J. Blyth ◽  
T. Sleet ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Stroke Rate ◽  
Current Investigation ◽  
Ratings Of Perceived Exertion ◽  
Carbohydrate Ingestion ◽  
Time Trial Performance ◽  
Maltodextrin Solution ◽  
Carbohydrate Solution ◽  
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.

Acute Capsaicin Supplementation Improves 1,500-m Running Time-Trial Performance and Rate of Perceived Exertion in Physically Active Adults

2018 ◽  
Vol 32 (2) ◽  
pp. 572-577 ◽  
Author(s):  
Marcelo Conrado de Freitas ◽  
Jason M. Cholewa ◽  
Luis A. Gobbo ◽  
João V.N.S. de Oliveira ◽  
Fabio S. Lira ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Physically Active ◽  
Running Time ◽  
Time Trial Performance ◽  
Rate Of Perceived Exertion ◽  
Active Adults ◽  
Trial Performance

Improved Cycling Time-Trial Performance after Ingestion of a Caffeine Energy Drink

2009 ◽  
Vol 19 (1) ◽  
pp. 61-78 ◽  
Author(s):  
John L. Ivy ◽  
Lynne Kammer ◽  
Zhenping Ding ◽  
Bei Wang ◽  
Jeffrey R. Bernard ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Time Trial ◽  
Endurance Performance ◽  
Energy Drink ◽  
Rating Of Perceived Exertion ◽  
Double Blind ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Cycling Time ◽  
Trial Performance

Context:Not all athletic competitions lend themselves to supplementation during the actual event, underscoring the importance of preexercise supplementation to extend endurance and improve exercise performance. Energy drinks are composed of ingredients that have been found to increase endurance and improve physical performance.Purpose:The purpose of the study was to investigate the effects of a commercially available energy drink, ingested before exercise, on endurance performance.Methods:The study was a double-blind, randomized, crossover design. After a 12-hr fast, 6 male and 6 female trained cyclists (mean age 27.3 ± 1.7 yr, mass 68.9 ± 3.2 kg, and VO2 54.9 ± 2.3 ml · kg–1 · min–1) consumed 500 ml of either flavored placebo or Red Bull Energy Drink (ED; 2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 μg vitamin B12) 40 min before a simulated cycling time trial. Performance was measured as time to complete a standardized amount of work equal to 1 hr of cycling at 70% Wmax.Results:Performance improved with ED compared with placebo (3,690 ± 64 s vs. 3,874 ± 93 s, p < .01), but there was no difference in rating of perceived exertion between treatments. β-Endorphin levels increased during exercise, with the increase for ED approaching significance over placebo (p = .10). Substrate utilization, as measured by open-circuit spirometry, did not differ between treatments.Conclusion:These results demonstrate that consuming a commercially available ED before exercise can improve endurance performance and that this improvement might be in part the result of increased effort without a concomitant increase in perceived exertion.

scholarly journals The Effects of Carbohydrate and Caffeine Mouth Rinsing on Arm Crank Time-Trial Performance

2015 ◽  
Vol 1 (2) ◽  
pp. 34-44
Author(s):  
Jonathan Sinclair ◽  
Lindsay Bottoms
Keyword(s):  
Power Output ◽  
Perceived Exertion ◽  
Time Trial ◽  
Mouth Rinse ◽  
Current Investigation ◽  
Ratings Of Perceived Exertion ◽  
Arm Cranking ◽  
Time Trial Performance ◽  
Mouth Rinsing ◽  
Trial Performance

This study aimed to determine whether carbohydrate (CHO) and caffeine (CAFF) mouth rinsing would improve 30 minute arm cranking time-trial performance. Twelve male participants (age 21.54 ± 1.28 years, height 179.46 ± 7.38 cm and mass 73.69 ± 5.40 kg) took part in the current investigation. Participants came to the laboratory on 3 occasions during which they performed 30 minute self-paced arm crank time trials. On one occasion water was given as a mouth rinse for 5 s (PLA), on another occasion a 6.4% CHO solution was given for 5 s and finally a 0.032% CAFF solution was given for 5s. Key measurements of distance covered, heart rate (HR), ratings of perceived exertion (RPE), cadence and power output were recorded throughout all trials. Distance covered during the CAFF (15.43 ± 3.27 km) and CHO (15.30 ± 3.31) mouth rinse trials were significantly (p<0.05) greater in comparison to PLA (13.15 ± 3.36 km). Cadence and power output and velocity were also significantly greater during the CAFF and CHO trials compared to PLA and CHO (p<0.05). No significant (P>0.05) differences between trials were observed for HR and RPE. CAFF and CHO mouth rinse serve to improve 30 minute arm cranking performance by mediating increasing cadence and power output without a concurrent increase in RPE and HR.

scholarly journals Doubling of Muscle Carnosine Concentration Does Not Improve Laboratory 1-Hr Cycling Time-Trial Performance

2014 ◽  
Vol 24 (3) ◽  
pp. 315-324 ◽  
Author(s):  
Weiliang Chung ◽  
Audrey Baguet ◽  
Tine Bex ◽  
David J. Bishop ◽  
Wim Derave
Keyword(s):  
Time Trial ◽  
Controlled Study ◽  
Resonance Spectroscopy ◽  
Muscle Carnosine ◽  
Time Trial Performance ◽  
Beta Alanine ◽  
Cycling Time Trial ◽  
Physiological Variables ◽  
Cycling Time ◽  
Trial Performance

Muscle carnosine loading through chronic oral beta-alanine supplementation has been shown to be effective for short-duration, high-intensity exercise. This randomized, placebo-controlled study explored whether the ergogenic effect of beta-alanine supplementation is also present for longer duration exercise. Subjects (27 well-trained cyclists/triathletes) were supplemented with either beta-alanine or placebo (6.4 g/day) for 6 weeks. Time to completion and physiological variables for a 1-hr cycling time-trial were compared between preand postsupplementation. Muscle carnosine concentration was also assessed via proton magnetic resonance spectroscopy before and after supplementation. Following beta-alanine supplementation, muscle carnosine concentration was increased by 143 ± 151% (mean ± SD; p < .001) in the gastrocnemius and 161 ± 56% (p < .001) in the soleus. Postsupplementation time trial performance was significantly slower in the placebo group (60.6 ± 4.4–63.0 ± 5.4 min; p < .01) and trended toward a slower performance following beta-alanine supplementation (59.8 ± 2.8–61.7 ± 3.0 min; p = .069). We found an increase in lactate/proton concentration ratio following beta-alanine supplementation during the time-trial (209.0 ± 44.0 (beta-alanine) vs. 161.9 ± 54.4 (placebo); p < .05), indicating that a similar lactate concentration was accompanied by a lower degree of systemic acidosis, even though this acidosis was quite moderate (pH ranging from 7.30 to 7.40). In conclusion, chronic beta-alanine supplementation in well-trained cyclists had a very pronounced effect on muscle carnosine concentration and a moderate attenuating effect on the acidosis associated with lactate accumulation, yet without affecting 1-h time-trial performance under laboratory conditions.

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