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

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.

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Dietary Antioxidant Supplementation Combined with Quercetin Improves Cycling Time Trial Performance

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.16.4.405 ◽

2006 ◽

Vol 16 (4) ◽

pp. 405-419 ◽

Cited By ~ 68

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.

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Reliability of Physiological Attributes and Their Association With Stochastic Cycling Performance

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2013-0048 ◽

2014 ◽

Vol 9 (2) ◽

pp. 309-315 ◽

Cited By ~ 2

Author(s):

Gregory T. Levin ◽

Paul B. Laursen ◽

Chris R. Abbiss

Keyword(s):

Power Output ◽

Ventilatory Threshold ◽

Intraclass Correlation ◽

Time Trial ◽

Cycling Performance ◽

Peak Power Output ◽

Cycling Time Trial ◽

Physiological Variables ◽

Physiological Attributes ◽

And Performance

Purpose:To assess the reliability of a 5-min-stage graded exercise test (GXT) and determine the association between physiological attributes and performance over stochastic cycling trials of varying distance.Methods:Twenty-eight well-trained male cyclists performed 2 GXTs and either a 30-km (n = 17) or a 100-km stochastic cycling time trial (n = 9). Stochastic cycling trials included periods of high-intensity efforts for durations of 250 m, 1 km, or 4 km depending on the test being performing.Results:Maximal physiological attributes were found to be extremely reliable (maximal oxygen uptake [VO2max]: coefficient of variation [CV] 3.0%, intraclass correlation coefficient [ICC] .911; peak power output [PPO]: CV 3.0%, ICC .913), but a greater variability was found in ventilatory thresholds and economy. All physiological variables measured during the GXT, except economy at 200 W, were correlated with 30-km cycling performance. Power output during the 250-m and 1-km efforts of the 30-km trial were correlated with VO2max, PPO, and the power output at the second ventilatory threshold (r = .58–.82). PPO was the only physiological attributed measured during the GXT to be correlated with performance during the 100-km cycling trial (r = .64).Conclusions:Many physiological variables from a reliable GXT were associated with performance over shorter (30-km) but not longer (100-km) stochastic cycling trials.

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Metabolic Responses When Different Forms of Carbohydrate Energy Are Consumed during Cycling

International Journal of Sport Nutrition ◽

10.1123/ijsn.3.4.398 ◽

1993 ◽

Vol 3 (4) ◽

pp. 398-407 ◽

Cited By ~ 11

Author(s):

Manuel Lugo ◽

William M. Sherman ◽

Gregory S. Wimer ◽

Keith Garleb

Keyword(s):

Time Trial ◽

Blood Parameters ◽

Metabolic Responses ◽

Moderate Intensity ◽

Liquid Form ◽

Total Carbohydrate ◽

Time Trial Performance ◽

Cycling Time Trial ◽

And Performance ◽

Trial Performance

This study examined the effects of consuming the same amount of carbohydrate in solid form, liquid form, or both on metabolic responses during 2 hrs of cycling at 70% peak VO2and on cycling time-trial performance. Subjects consumed 0.4 g carbohydrate/kg body mass before and every 30 min during exercise. The liquid was a 7% carbohydrate-electrolyte beverage and the solid was a sports bar (1171 kJ) in which 76%, 18%, and 6% of total energy was derived from carbohydrate, fat, and protein, respectively. Blood obtained at baseline, before exercise, and every 30 min was analyzed for glucose, insulin, lactate, hemoglobin, hematocrit, and plasma volume. There were no differences among the treatments for the blood parameters. Total carbohydrate oxidation and time-trial performance were also similar among treatments. Under thermoneutral conditions with equal liquid inges-tion, the metabolic and performance responses are similar when consuming carbohydrate as a liquid, solid, or in combination during prolonged, moderate intensity cycling.

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The Potential to Change Pacing and Performance During 4000-m Cycling Time Trials Using Hyperoxia and Inspired Gas-Content Deception

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2018-0335 ◽

2019 ◽

Vol 14 (7) ◽

pp. 949-957

Author(s):

Michael J. Davies ◽

Bradley Clark ◽

Laura A. Garvican-Lewis ◽

Marijke Welvaert ◽

Christopher J. Gore ◽

...

Keyword(s):

Confidence Interval ◽

Time Trial ◽

Cycling Performance ◽

Peak Oxygen Uptake ◽

Gas Content ◽

Cycling Time Trial ◽

Fraction Of Inspired Oxygen ◽

And Performance ◽

Inspired Oxygen ◽

Cycling Time

Purpose: To determine if a series of trials with fraction of inspired oxygen (FiO2) content deception could improve 4000-m cycling time-trial (TT) performance. Methods: A total of 15 trained male cyclists (mean [SD] body mass 74.2 [8.0] kg, peak oxygen uptake 62 [6] mL·kg−1·min−1) completed six 4000-m cycling TTs in a semirandomized order. After a familiarization TT, cyclists were informed in 2 initial trials they were inspiring normoxic air (NORM, FiO2 0.21); however, in 1 trial (deception condition), they inspired hyperoxic air (NORM-DEC, FiO2 0.36). During 2 subsequent TTs, cyclists were informed they were inspiring hyperoxic air (HYPER, FiO2 0.36), but in 1 trial, normoxic air was inspired (HYPER-DEC). In the final TT (NORM-INFORM), the deception was revealed and cyclists were asked to reproduce their best TT performance while inspiring normoxic air. Results: Greater power output and faster performances occurred when cyclists inspired hyperoxic air in both truthful (HYPER) and deceptive (NORM-DEC) trials than NORM (P < .001). However, performance only improved in NORM-INFORM (377 W; 95% confidence interval [CI] 325–429) vs NORM (352 W; 95% CI 299–404; P < .001) when participants (n = 4) completed the trials in the following order: NORM-DEC, NORM, HYPER-DEC, HYPER. Conclusions: Cycling performance improved with acute exposure to hyperoxia. Mechanisms for the improvement were likely physiological; however, improvement in a deception trial suggests an additional placebo effect. Finally, a particular sequence of oxygen deception trials may have built psychophysiological belief in cyclists such that performance improved in a subsequent normoxic trial.

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

Journal of Applied Physiology ◽

10.1152/japplphysiol.01026.2018 ◽

2019 ◽

Vol 126 (4) ◽

pp. 870-879 ◽

Cited By ~ 4

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.

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

Nutrients ◽

10.3390/nu11112575 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2575 ◽

Cited By ~ 4

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.

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

Journal of Applied Physiology ◽

10.1152/jappl.2000.88.1.113 ◽

2000 ◽

Vol 88 (1) ◽

pp. 113-119 ◽

Cited By ~ 61

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.

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