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.

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 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.

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 INFLUENCE OF AN AMARANTH-BASED BEVERAGE ON CYCLING PERFORMANCE: A PILOT STUDY

Biotecnia ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 31-36
Author(s):  
Ever Espino-González ◽  
María J. Muñoz-Daw ◽  
Juan M. Rivera-Sosa ◽  
María L. De la Torre-Díaz ◽  
Gabriel E. Cano-Olivas ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Average Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Hydration Status ◽  
Caloric Content ◽  
Ratings Of Perceived Exertion ◽  
Exercise Tests ◽  
Sports Beverage ◽  
Trial Performance

The present study aimed to evaluate the effectiveness of an amaranth-based beverage (CHO-P) on cycling performance and hydration status, despite containing a total caloric content higher than that of a commercial sports beverage (CHO-P: 52.48 kcal per 100 mL vs CHO: 24 kcal per 100 mL). In a randomized, crossover design, six cyclists performed two exercise tests separated by seven days. Each test comprised two time-trials (32.20 km and 5 km) separated by 10 min of rest. Participants consumed either an amaranth-based beverage (CHO-P; 10% and 1.5% concentrations) or a commercial sports beverage (CHO; 6%). Changes in hematocrit and body mass, ratings of perceived exertion, and average power were assessed throughout both tests. 32.2-km time-trial performance was enhanced with CHO-P compared to CHO (54.3 ± 4.1 min vs 55.6 ± 4.8 min; p<0.05). However, no other variablemeasured in this study was significantly different between beverage types. Further laboratory based research should be performed to further explore the ergogenic potential of amaranth supplementation during endurance exercise.

scholarly journals Caffeine but not acetaminophen increases 4-km cycling time-trial performance

2019 ◽  
Author(s):  
Fabiano Tomazini ◽  
Ana Carla S. Mariano ◽  
Victor A. Andrade-Souza ◽  
Viviane C. Sebben ◽  
Carlos A. B. de Maria ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Body Mass ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Plasma Lactate ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Cycling Time

AbstractAcetaminophen has been combined with caffeine for therapeutic purpose, but the effect of co-ingestion of acetaminophen and caffeine on exercise performance has not been investigated. The aim of this study was to determine the effect of isolated and combined ingestion of caffeine and acetaminophen on performance during a 4-km cycling time-trial. In a double-blind, crossover design, eleven men, accustomed to cycling recreationally, completed a 4-km cycling time-trial one hour after the ingestion of cellulose (PLA), acetaminophen (20 mg·kg−1body mass, ACT), caffeine (5 mg·kg−1body mass, CAF) or combined acetaminophen and caffeine (20 and 5 mg·kg−1body mass, respectively, ACTCAF). The perception of pain and rating of perceived exertion were recorded every 1-km, and electromyography and oxygen uptake were continually recorded and averaged each 1-km. Plasma lactate concentration was measured before and immediately after the trial. The time and mean power during the 4-km cycling time-trial was significantly improved (P< 0.05) in CAF (407.9 ± 24.5 s, 241.4 ± 16.1 W) compared to PLA (416.1 ± 34.1 s, 234.1 ± 19.2 W) and ACT (416.2 ± 26.6 s, 235.8 ± 19.7 W). However, there was no difference between ACTCAF (411.6 ± 27.7 s, 238.7 ± 18.7 W) and the other conditions (P> 0.05). The perception of pain, rating of perceived exertion, electromyography, oxygen uptake, and plasma lactate were similar across the conditions (P> 0.05). In conclusion, caffeine but not acetaminophen increases power output ultimately increasing performance during a 4-km cycling time-trial.

The Effect of a Caffeinated Mouth-Rinse on Endurance Cycling Time-Trial Performance

2014 ◽  
Vol 24 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Thomas M. Doering ◽  
James W. Fell ◽  
Michael D. Leveritt ◽  
Ben Desbrow ◽  
Cecilia M. Shing
Keyword(s):  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Mouth Rinse ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Physiological Variables ◽  
Endurance Cycling ◽  
Caffeine Exposure ◽  
Cycling Time ◽  
Trial Performance

The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved endurance cycling time-trial performance in well-trained cyclists. It was hypothesized that caffeine exposure at the mouth would enhance endurance cycling time-trial performance. Ten well-trained male cyclists (mean± SD: 32.9 ± 7.5 years, 74.7 ± 5.3kg, 176.8 ± 5.1cm, VO2peak = 59.8 ± 3.5ml·kg–1·min–1) completed two experimental timetrials following 24 hr of dietary and exercise standardization. A randomized, double-blind, placebo-controlled, cross-over design was employed whereby cyclists completed a time-trial in the fastest time possible, which was equivalent work to cycling at 75% of peak aerobic power output for 60 min. Cyclists were administered 25ml mouth-rinses for 10 s containing either placebo or 35mg of anhydrous caffeine eight times throughout the time-trial. Perceptual and physiological variables were recorded throughout. No significant improvement in time-trial performance was observed with caffeine (3918 ± 243s) compared with placebo mouth-rinse (3940 ± 227s). No elevation in plasma caffeine was detected due to the mouth-rinse conditions. Caffeine mouth-rinse had no significant effect on rating of perceived exertion, heart rate, rate of oxygen consumption or blood lactate concentration. Eight exposures of a 35 mg dose of caffeine at the buccal cavity for 10s does not significantly enhance endurance cycling time-trial performance, nor does it elevate plasma caffeine concentration.

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).

Coingestion of carbohydrate and protein during training reduces training stress and enhances subsequent exercise performance

2013 ◽  
Vol 38 (6) ◽  
pp. 597-604 ◽  
Author(s):  
Andrew H. Hall ◽  
Michael D. Leveritt ◽  
Kiran D.K. Ahuja ◽  
Cecilia M. Shing
Keyword(s):  
Heart Rate ◽  
Exercise Performance ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Time Trial ◽  
Rating Of Perceived Exertion ◽  
Exercise Stress ◽  
Subsequent Performance ◽  
Time Trial Performance ◽  
Trial Performance

Researchers have focused primarily on investigating the effects of coingesting carbohydrate (CHO) and protein (PRO) during recovery and, as such, there is limited research investigating the benefits of CHO+PRO coingestion during exercise for enhancing subsequent exercise performance. The aim of this study was to investigate whether coingestion of CHO+PRO during endurance training would enhance recovery and subsequent exercise performance. Ten well-trained male cyclists (aged 29.7 ± 7.5 years; maximal oxygen uptake, 66.2 ± 6 mL·kg−1·min−1) took part in a randomized, double-blind, cross-over trial. Each trial consisted of a 2.5-h morning training bout during which the cyclists ingested a CHO+PRO or energy-matched CHO beverage followed by a 4-h recovery period and a subsequent performance time trial (total work, 7 kJ·kg−1). Blood was collected before and after exercise. Time-trial performance was 1.8% faster in the CHO+PRO trial compared with the CHO trial (p = 0.149; 95% CI, −13 to 87 s; 75.8% likelihood of benefit). The increase in myoglobin level from before the training bout to after the training bout was lower in the CHO+PRO trial (0.74 nmol·L−1; 95% CI, 0.3–1.17 nmol·L−1) compared with the CHO trial (1.16 nmol·L−1; 95% CI, 0.6–1.71 nmol·L−1) (p = 0.018). Additionally, the decrease in neutrophil count over the recovery period was greater in the CHO+PRO trial (p = 0.034), and heart rate (p < 0.022) and rating of perceived exertion (RPE) (p < 0.01) were lower during training in the CHO+PRO trial compared with the CHO trial. Ingesting PRO, in addition to CHO, during strenuous training lowered exercise stress, as indicated by reduced heart rate, RPE, and muscle damage, when compared with CHO alone. CHO+PRO ingestion during training is also likely to enhance recovery, providing a worthwhile improvement in subsequent cycling time-trial performance.

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