Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance

2000 ◽  
Vol 88 (1) ◽  
pp. 113-119 ◽  
Author(s):  
Damien J. Angus ◽  
Mark Hargreaves ◽  
Jane Dancey ◽  
Mark A. Febbraio
Keyword(s):  
Performance Enhancement ◽  
Medium Chain Triglyceride ◽  
Time Trial ◽  
Cycling Performance ◽  
Medium Chain Triglycerides ◽  
Carbohydrate Ingestion ◽  
Medium Chain ◽  
Cycling Time Trial ◽  
Carbohydrate Solution ◽  
Trial Performance

This study examined the effectiveness of ingesting a carbohydrate or carbohydrate + medium-chain triglycerides (MCT) on metabolism and cycling performance. Eight endurance-trained men [peak O2 uptake = 4.71 ± 0.09 (SE) l/min] completed 35 kJ/kg as quickly as possible [time trial (TT)] while consuming 250 ml/15 min of either a 6% (wt/vol) carbohydrate solution (C), a 6% carbohydrate + 4.2% MCT solution (C+M), or a sweet placebo (P). Time to complete the set amount of work was reduced in both C and C+M compared with P by 7 and 5%, respectively (C: 166 ± 7 min; C+M: 169 ± 7 min; P: 178 ± 11 min; P < 0.01). Plasma glucose concentration was maintained at or above resting values throughout both C and C+M trials but decreased ( P < 0.05) below resting values in P at the completion of the TT. The estimated rate of carbohydrate oxidation was not different during the first 90 min of exercise but thereafter was reduced ( P < 0.05) in P and was maintained in both C and C+M. These data demonstrate that carbohydrate ingestion during exercise improves 100-km TT performance compared with a sweet placebo, but the addition of MCT does not provide any further performance enhancement.

Effects of medium-chain triglyceride ingestion on fuel metabolism and cycling performance

1996 ◽  
Vol 80 (6) ◽  
pp. 2217-2225 ◽  
Author(s):  
C. G. Van Zyl ◽  
E. V. Lambert ◽  
J. A. Hawley ◽  
T. D. Noakes ◽  
S. C. Dennis
Keyword(s):  
Medium Chain Triglyceride ◽  
Time Trial ◽  
Random Order ◽  
Cycling Performance ◽  
Medium Chain Triglycerides ◽  
O2 Uptake ◽  
Lactate Oxidation ◽  
Medium Chain ◽  
Oxidation Rates ◽  
Fuel Metabolism

On three occasions separated by 10 days, six endurance-trained cyclists rode for 2 h at 60% of peak O2 uptake and then performed a simulated 40-km time trial (T-trial). During the rides, the subjects ingested a total of 2 liters of a [U-14C]glucose-labeled beverage containing a random order of either 10% glucose [carbohydrate (CHO)], 4.3% medium-chain triglycerides (MCTs); or 10% glucose + 4.3% MCTs (CHO+MCT). Although replacing CHO with MCTs slowed the T-trials from 66.8 +/- 0.4 (SE) to 72.1 +/- 0.6 min (P < 0.001), adding MCTs to CHO improved the T-trials from 66.8 +/- 0.4 to 65.1 +/- 0.5 min (P < 0.05). Faster T-trials in the CHO+MCT trial than in the CHO trial were associated with increased final circulating concentrations of free fatty acids (0.58 +/- 0.09 vs. 0.36 +/- 0.06 mmol/l; P < 0.05) and ketones (1.51 +/- 0.25 vs. 0.51 +/- 0.07 mmol/l; P < 0.01) and decreased final circulating concentrations of glucose (5.2 +/- 0.2 vs. 6.3 +/- 0.3 mmol/l; P < 0.01) and lactate (1.9 +/- 0.4 vs. 3.7 +/- 0.5 mmol/l; P < 0.05). Adding MCTs to ingested CHO reduced total CHO oxidation rates from 14 +/- 1 to 10 +/- 1 mmol/min at 2 h and from 17 +/- 1 to 14 +/- 1 mmol/min in the T-trial (P < 0.01), without affecting the corresponding approximately 5 and approximately 7 mmol/min rates of [14C]glucose oxidation. These data suggest that MCT oxidation decreased the direct and/or indirect (via lactate) oxidation of muscle glycogen. A reduced reliance on CHO oxidation at a given O2 uptake is similar to an endurance-training effect, and that may explain the improved T-trial performances.

Dietary Antioxidant Supplementation Combined with Quercetin Improves Cycling Time Trial Performance

2006 ◽  
Vol 16 (4) ◽  
pp. 405-419 ◽  
Author(s):  
Holden S-H. MacRae ◽  
Kari M. Mefferd
Keyword(s):  
Peak Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Antioxidant Supplementation ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Dietary Antioxidant ◽  
Power Peak ◽  
Manova Analysis ◽  
Trial Performance

We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline TT (B). MANOVA analysis showed that time to complete the 30 km TT was improved by 3.1% on FRS compared to B (P ≤ 0.01), and by 2% over the last 5 km (P ≤ 0.05). Absolute and relative (%HRmax) heart rates and percent VO2max were not different between trials, but average and relative power (% peak power) was higher on FRS (P ≤ 0.01). Rates of carbohydrate and fat oxidation were not different between trials. Thus, FRS supplementation significantly improved high-intensity cycling TT performance through enhancement of power output. Further study is needed to determine the potential mechanism(s) of the antioxidant efficacy.

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.

scholarly journals Cycling time trial performance is improved by carbohydrate ingestion during exercise regardless of a fed or fasted state

2019 ◽  
Vol 29 (5) ◽  
pp. 651-662 ◽  
Author(s):  
Sara K. Learsi ◽  
Thaysa Ghiarone ◽  
Marcos D. Silva‐Cavalcante ◽  
Victor A. Andrade‐Souza ◽  
Thays Ataide‐Silva ◽  
...  
Keyword(s):  
Time Trial ◽  
Carbohydrate Ingestion ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Fasted State ◽  
Cycling Time ◽  
Trial Performance

The Effect of Crank Arm Length on Cycling Economy and Performance in Triathlon

2021 ◽  
Vol 2 (2) ◽  
pp. 4-7
Author(s):  
Boram Lim ◽  
John Mercer
Keyword(s):  
Time Trial ◽  
Cycling Performance ◽  
Important Indicator ◽  
Cycling Time Trial ◽  
Rate Of Oxygen Consumption ◽  
Biomechanical Responses ◽  
Physiological Demands ◽  
And Performance ◽  
Selection Of ◽  
Trial Performance

Given the nature of a triathlon race, the cycling distance is typically much longer than swimming and running across race distances from sprint to Ironman. Besides, triathletes should try to not only maintain a certain level of cycling power but also consider cycling economy to make a better performance in both the cycling portion and the overall race (Bonacci et al., 2013; Sleivert & Rowland, 1996; Swinnen et al., 2018). The cycling economy is an important indicator to predict cycling performance in terms of time to complete a certain distance. Both cycling economy and performance are determined by the interaction between mechanical output and physiological input (Barratt et al., 2016; Korff et al., 2007; Sunde et al., 2010). Theoretically, improving cycling economy elicits a better cycling time trial performance and/or less physiological demands (e.g., rate of oxygen consumption: V̇O2, heart rate) to complete at a given distance. The crank arm length (CAL) is one of the important factors among many variables that affect the economy and performance in cycling (McDaniel et al., 2002). Therefore, the appropriate selection of CAL may play a key role in improving the cycling portion of the race and entire triathlon performance. The purpose of this review is to identify the effects of acute changing CAL on physiological and biomechanical responses during cycling.

The Effects of Medium-Chain Triacylglycerol and Carbohydrate Ingestion on Ultra-Endurance Exercise Performance

2005 ◽  
Vol 15 (1) ◽  
pp. 15-27 ◽  
Author(s):  
Julia H. Goedecke ◽  
Virginia R. Clark ◽  
Timothy D. Noakes ◽  
Estelle V. Lambert
Keyword(s):  
Time Trial ◽  
Cycling Performance ◽  
Constant Load ◽  
Peak Power Output ◽  
Carbohydrate Ingestion ◽  
Medium Chain ◽  
Substrate Metabolism ◽  
Endurance Cycling ◽  
Gi Symptoms ◽  
Ultra Endurance

The aims of the study were to determine if medium-chain triacylglycerol (MCT), ingested in combination with carbohydrate (CHO), would alter substrate metabolism and improve simulated competitive ultra-endurance cycling performance. Eight endurance-trained cyclists took part in this randomized, single-blind crossover study. On two separate occasions, subjects cycled for 270 min at 50% of peak power output, interspersed with four 75 kJ sprints at 60 min intervals, followed immediately by a 200 kJ time-trial. One hour prior to the exercise trials, subjects ingested either 75 g of CHO or 32 g of MCT, and then ingested 200 mL of a 10% CHO (wt/vol) solution or a 4.3% MCT + 10% CHO (wt/vol) solution every 20 min during the CHO and MCT trials, respectively. During the constant-load phases of the 270 min exercise trial, VO2, RER, and heart rate were measured at 30 min intervals and gastrointestinal (GI) symptoms were recorded. There was no difference in VO2 or RER between the MCT and CHO trials (P = 0.40). Hourly sprint (P = 0.03 for trial x time interaction) and time-trial times (14:30 ± 0.58 vs. 12:36 ± 1:6, respectively, P < 0.001) were slower in the MCT than the CHO trial. Half the subjects experienced GI symptoms with MCT ingestion. In conclusion, MCTs ingested prior to exercise and co-ingested with CHO during exercise did not alter substrate metabolism and significantly compromised sprint performance during prolonged ultra-endurance cycling exercise.

Quinine Ingestion During the Latter Stages of a 3,000-m Time Trial Fails to Improve Cycling Performance

2020 ◽  
pp. 1-4
Author(s):  
Naroa Etxebarria ◽  
Brad Clark ◽  
Megan L. Ross ◽  
Timothy Hui ◽  
Roland Goecke ◽  
...  
Keyword(s):  
Power Output ◽  
Time Trial ◽  
Cycling Performance ◽  
Water Control ◽  
Double Blind ◽  
Cycling Time Trial ◽  
S Cycling ◽  
Last Stage ◽  
And Control ◽  
Carbohydrate Solution

The ingestion of quinine, a bitter tastant, improves short-term (30 s) cycling performance, but it is unclear whether this effect can be integrated into the last effort of a longer race. The purpose of this study was to determine whether midtrial quinine ingestion improves 3,000-m cycling time-trial (TT) performance. Following three familiarization TTs, 12 well-trained male cyclists (mean ± SD: mass = 76.6 ± 9.2 kg, maximal aerobic power = 390 ± 50 W, maximal oxygen uptake = 4.7 ± 0.6 L/min) performed four experimental 3,000-m TTs on consecutive days. This double-blind, crossover design study had four randomized and counterbalanced conditions: (a) Quinine 1 (25-ml solution, 2 mM of quinine); (b) Quinine 2, replicate of Quinine 1; (c) a 25-ml sweet-tasting no-carbohydrate solution (Placebo); and (d) 25 ml of water (Control) consumed at the 1,850-m point of the TT. The participants completed a series of perceptual scales at the start and completion of all TTs, and the power output was monitored continuously throughout all trials. The power output for the last 1,000 m for all four conditions was similar: mean ± SD: Quinine 1 = 360 ± 63 W, Quinine 2 = 367 ± 63 W, Placebo = 364 ± 64 W, and Control = 367 ± 58 W. There were also no differences in the 3,000-m TT power output between conditions. The small perceptual differences between trials at specific 150-m splits were not explained by quinine intake. Ingesting 2 mM of quinine during the last stage of a 3,000-m TT did not improve cycling performance.

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.

scholarly journals Coffee Ingestion Improves 5 km Cycling Performance in Men and Women by a Similar Magnitude

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2575 ◽  
Author(s):  
Neil D. Clarke ◽  
Nicholas A. Kirwan ◽  
Darren L. Richardson
Keyword(s):  
Sex Differences ◽  
Time Trial ◽  
Cycling Performance ◽  
Similar Magnitude ◽  
Men And Women ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
And Control ◽  
Cycling Time ◽  
Trial Performance

Caffeine is a well-established ergogenic aid, although research to date has predominantly focused on anhydrous caffeine, and in men. The primary aim of the present study was to investigate the effect of coffee ingestion on 5 km cycling time trial performance, and to establish whether sex differences exist. A total of 38 participants (19 men and 19 women) completed a 5 km time trial following the ingestion of 0.09 g·kg-1 coffee providing 3 mg·kg-1 of caffeine (COF), a placebo (PLA), in 300 mL of water, or control (CON). Coffee ingestion significantly increased salivary caffeine levels (p < 0.001; η P 2 = 0.75) and, overall, resulted in improved 5 km time trial performance (p < 0.001; η P 2 = 0.23). Performance following COF (482 ± 51 s) was faster than PLA (491 ± 53 s; p = 0.002; d = 0.17) and CON (487 ± 52 s; p =0.002; d = 0.10) trials, with men and women both improving by approximately 9 seconds and 6 seconds following coffee ingestion compared with placebo and control, respectively. However, no differences were observed between CON and PLA (p = 0.321; d = 0.08). In conclusion, ingesting coffee providing 3 mg·kg-1 of caffeine increased salivary caffeine levels and improved 5 km cycling time trial performance in men and women by a similar magnitude.

Sign in / Sign up

Export Citation Format

Share Document