The Influence of Blood Removal on Pacing During a 4-Minute Cycling Time Trial

2017 ◽  
Vol 12 (8) ◽  
pp. 1085-1092
Author(s):  
Nathan G. Lawler ◽  
Chris R. Abbiss ◽  
Aaron Raman ◽  
Timothy J. Fairchild ◽  
Garth L. Maker ◽  
...  
Keyword(s):  
Power Output ◽  
Average Power ◽  
Time Trial ◽  
Energy Contribution ◽  
Cycling Time Trial ◽  
Baseline Testing ◽  
Average Power Output ◽  
Rate Of Decline ◽  
Aerobic And Anaerobic ◽  
Cycling Time

Purpose:To examine the influence of manipulating aerobic contribution after whole-blood removal on pacing patterns, performance, and energy contribution during self-paced middle-distance cycling.Methods:Seven male cyclists (33 ± 8 y) completed an incremental cycling test followed 20 min later by a 4-min self-paced cycling time trial (4MMP) on 6 separate occasions over 42 d. The initial 2 sessions acted as familiarization and baseline testing, after which 470 mL of blood was removed, with the remaining sessions performed 24 h, 7 d, 21 d, and 42 d after blood removal. During all 4MMP trials, power output, oxygen uptake, and aerobic and anaerobic contribution to power were determined.Results:4MMP average power output significantly decreased by 7% ± 6%, 6% ± 8%, and 4% ± 6% at 24 h, 7 d, and 21 d after blood removal, respectively. Compared with baseline, aerobic contribution during the 4MMP was significantly reduced by 5% ± 4%, 4% ± 5%, and 4% ± 10% at 24 h, 7 d, and 21 d, respectively. The rate of decline in power output on commencement of the 4MMP was significantly attenuated and was 76% ± 20%, 72% ± 24%, and 75% ± 35% lower than baseline at 24 h, 21 d, and 42 d, respectively.Conclusion:Removal of 470 mL of blood reduces aerobic energy contribution, alters pacing patterns, and decreases performance during self-paced cycling. These findings indicate the importance of aerobic energy distribution during self-paced middle-distance events.

scholarly journals Tramadol effects on physical performance and sustained attention during a 20-min indoor cycling time-trial: A randomised controlled trial

2017 ◽  
Author(s):  
Darias Manuel Holgado Nuñez ◽  
Thomas Zandonai ◽  
Mikel Zabala ◽  
James Hopker ◽  
Pandelis Perakakis ◽  
...  
Keyword(s):  
Sustained Attention ◽  
Power Output ◽  
Cognitive Task ◽  
Average Power ◽  
Time Trial ◽  
Placebo Condition ◽  
Time Frequency ◽  
Cycling Time Trial ◽  
Oddball Task ◽  
Cycling Time

Objectives: To investigate the effect of tramadol on performance during a 20-min cycling time-trial (Experiment 1), and to test whether sustained attention would be impaired during cycling after tramadol intake (Experiment 2).Design: randomized, double-blind, placebo controlled trial.Methods: In Experiment 1, participants completed a cycling time-trial, 120-min after they ingested either tramadol or placebo. In Experiment 2, participants performed a visual Oddball task during the time-trial. Electroencephalography measures (EEG) were recorded throughout the session.Results: In Experiment 1, average time-trial power output was higher in the tramadol vs. placebo condition (tramadol: 220 watts vs. placebo: 209 watts; p < 0.01). In Experiment 2, no differences between conditions were observed in the average power output (tramadol: 234 watts vs. placebo: 230 watts; p > 0.05). No behavioural differences were found between conditions in the Oddball task. Crucially, the time frequency analysis in Experiment 2 revealed an overall lower target-locked power in the beta-band (p < 0.01), and higher alpha suppression (p < 0.01) in the tramadol vs. placebo condition. At baseline, EEG power spectrum was higher under tramadol than under placebo in Experiment 1 while the reverse was true for Experiment 2.Conclusions: Tramadol improved cycling power output in Experiment 1, but not in Experiment 2, which may be due to the simultaneous performance of a cognitive task. Interestingly enough, the EEG data in Experiment 2 pointed to an impact of tramadol on stimulus processing related to sustained attention.Trial registration: EudraCT number: 2015-005056-96.

scholarly journals Does caffeine supplementation alter energy contribution during a work-based ~30 min cycling time-trial?

2020 ◽  
Vol 34 (3) ◽  
pp. 471-481
Author(s):  
Gabriel Barreto ◽  
Rafael Pires da Silva ◽  
Guilherme Yamaguchi ◽  
Luana Farias de Oliveira ◽  
Vitor de Salles Painelli ◽  
...  
Keyword(s):  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Time Trial ◽  
Energy System ◽  
Energy Contribution ◽  
Mean Power ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Cycling Time

Caffeine has been shown to increase anaerobic energy contribution during short-duration cycling time-trials (TT) though no information exists on whether caffeine alters energy contribution during more prolonged, aerobic type TTs. The aim of this study was to determine the effects of caffeine supplementation on longer and predominantly aerobic exercise. Fifteen recreationally-trained male cyclists (age 38±8 y, height 1.76±0.07 m, body mass 72.9±7.7 kg) performed a ~30 min cycling TT following either 6 mg·kg-1BM caffeine (CAF) or placebo (PLA) supplementation, and one control (CON) session without supplementation, in a double- -blind, randomised, counterbalance and cross-over design. Mean power output (MPO) was recorded as the outcome measure. Respiratory values were measured throughout exercise for the determination of energy system contribution. Data were analysed using mixed-models. CAF improved mean MPO compared to CON (P=0.01), and a trend towards an improvement compared to PLA (P=0.07); there was no difference in MPO at any timepoint throughout the exercise between conditions. There was a main effect of Condition (P=0.04) and Time (P<0.0001) on blood lactate concentration, which tended to be higher in CAF vs. both PLA and CON (Condition effect, both P=0.07). Ratings of perceived exertion increased over time (P<0.0001), with no effect of Condition or interaction (both P>0.05). Glycolytic energy contribution was increased in CAF compared to CON and PLA (both P<0.05), but not aerobic or ATP-CP (both P>0.05). CAF improved aerobic TT performance compared to CON, which could be explained by increased glycolytic energy contribution.

scholarly journals Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance

2016 ◽  
Vol 41 (8) ◽  
pp. 864-871 ◽  
Author(s):  
Phillip M. Bellinger ◽  
Clare L. Minahan
Keyword(s):  
Oxygen Uptake ◽  
Power Output ◽  
Maximal Oxygen Uptake ◽  
Anaerobic Power ◽  
Anaerobic Capacity ◽  
Time Trial ◽  
Time To Exhaustion ◽  
Cycling Test ◽  
Cycling Time Trial ◽  
Aerobic And Anaerobic

The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min−1) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (−6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

scholarly journals Effect of Warm-Up and Precooling on Pacing During a 15-km Cycling Time Trial in the Heat

2013 ◽  
Vol 8 (3) ◽  
pp. 307-311 ◽  
Author(s):  
Koen Levels ◽  
Lennart P.J. Teunissen ◽  
Arnold de Haan ◽  
Jos J. de Koning ◽  
Bernadet van Os ◽  
...  
Keyword(s):  
Power Output ◽  
Thermal Sensation ◽  
Heat Content ◽  
Time Trial ◽  
Scalp Cooling ◽  
Ice Slurry ◽  
Mean Power ◽  
Warm Up ◽  
Cycling Time Trial ◽  
Cycling Time

Purpose:The best way to apply precooling for endurance exercise in the heat is still unclear. The authors analyzed the effect of different preparation regimens on pacing during a 15-km cycling time trial in the heat.Methods:Ten male subjects completed four 15-km time trials (30°C), preceded by different preparation regimes: 10 min cycling (WARM-UP), 30 min scalp cooling of which 10 min was cycling (SC+WARM-UP), ice-slurry ingestion (ICE), and ice slurry ingestion + 30 min scalp cooling (SC+ICE).Results:No differences were observed in finish time and mean power output, although power output was lower for WARM-UP than for SC+ICE during km 13–14 (17 ± 16 and 19 ± 14 W, respectively) and for ICE during km 13 (16 ± 16 W). Rectal temperature at the start of the time trial was lower for both ICE conditions (~36.7°C) than both WARMUP conditions (~37.1°C) and remained lower during the first part of the trial. Skin temperature and thermal sensation were lower at the start for SC+ICE.Conclusions:The preparation regimen providing the lowest body-heat content and sensation of coolness at the start (SC+ICE) was most beneficial for pacing during the latter stages of the time trial, although overall performance did not differ.

scholarly journals Influence of Environmental Temperature on 40 km Cycling Time-Trial Performance

2011 ◽  
Vol 6 (2) ◽  
pp. 208-220 ◽  
Author(s):  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss
Keyword(s):  
Core Temperature ◽  
Power Output ◽  
Environmental Temperature ◽  
Core Body Temperature ◽  
Time Trial ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Pacing Strategies ◽  
Cycling Time ◽  
Trial Performance

The purpose of this study was to examine the effect of environmental temperature on variability in power output, self-selected pacing strategies, and performance during a prolonged cycling time trial. Nine trained male cyclists randomly completed four 40 km cycling time trials in an environmental chamber at 17°C, 22°C, 27°C, and 32°C (40% RH). During the time trials, heart rate, core body temperature, and power output were recorded. The variability in power output was assessed with the use of exposure variation analysis. Mean 40 km power output was significantly lower during 32°C (309 ± 35 W) compared with 17°C (329 ± 31 W), 22°C (324 ± 34 W), and 27°C (322 ± 32 W). In addition, greater variability in power production was observed at 32°C compared with 17°C, as evidenced by a lower (P = .03) standard deviation of the exposure variation matrix (2.9 ± 0.5 vs 3.5 ± 0.4 units, respectively). Core temperature was greater (P < .05) at 32°C compared with 17°C and 22°C from 30 to 40 km, and the rate of rise in core temperature throughout the 40 km time trial was greater (P < .05) at 32°C (0.06 ± 0.04°C·km–1) compared with 17°C (0.05 ± 0.05°C·km–1). This study showed that time-trial performance is reduced under hot environmental conditions, and is associated with a shift in the composition of power output. These finding provide insight into the control of pacing strategies during exercise in the heat.

Power Output Demands of Womenʼs Road Cycling Time Trial

2006 ◽  
Vol 38 (Supplement) ◽  
pp. S235 ◽  
Author(s):  
David T. Martin ◽  
Hamilton Lee ◽  
Cassie Trewin ◽  
James Victor ◽  
Warren McDonald ◽  
...  
Keyword(s):  
Power Output ◽  
Time Trial ◽  
Cycling Time Trial ◽  
Road Cycling ◽  
Cycling Time

Carbohydrate-Electrolyte Feedings and 1h Time Trial Cycling Performance

2004 ◽  
Vol 14 (5) ◽  
pp. 541-549 ◽  
Author(s):  
Ben Desbrow ◽  
Sally Anderson ◽  
Jennifer Barrett ◽  
Elissa Rao ◽  
Mark Hargreaves
Keyword(s):  
Power Output ◽  
High Intensity ◽  
Average Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Dietary Regimen ◽  
Trained Subjects ◽  
Sports Drink ◽  
Average Power Output ◽  
Glucose Availability

The effects of a commercial sports drink on performance in high-intensity cycling was investigated. Nine well-trained subjects were asked to complete a set amount of work as fast as possible (time trial) following 24 h of dietary (subjects were provided with food, energy 57.4 ± 2.4 kcal/kg and carbohydrate 9.1 ± 0.4 g/kg) and exercise control. During exercise, subjects were provided with 14 mL/kg of either 6% carbohydrate-electrolyte (CHO-E) solution or carbohydrate-free placebo (P). Results showed that subjects’ performances did not greatly improve (time, 62:34 ± 6:44 min:sec (CHO-E) vs. 62:40 ± 5:35 min:sec (P); average power output, 283.0 ± 25.0 W (CHO-E) vs. 282.9 ± 29.3 W (P), P > 0.05) while consuming the sports drink. It was concluded that CHO-E consumption throughout a 1-h time trial, following a pre-exercise dietary regimen designed to optimize glucose availability, did not improve time or power output to a greater degree than P in well-trained cyclists.

scholarly journals The Influence of Elliptical Chainrings on 10 km Cycling Time Trial Performance

2010 ◽  
Vol 5 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Jeremiah J. Peiffer ◽  
Chris R. Abbiss
Keyword(s):  
Heart Rate ◽  
Power Output ◽  
Time Trial ◽  
Total Power ◽  
Mean Power ◽  
Actual Performance ◽  
Cycling Time Trial ◽  
And Performance ◽  
Mean Power Output ◽  
Cycling Time

The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclists completed, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion of the study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or either elliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.

The Isocapnic Buffering Phase and Mechanical Efficiency: Relationship to Cycle Time Trial Performance of Short and Long Duration

2005 ◽  
Vol 30 (1) ◽  
pp. 46-60 ◽  
Author(s):  
David J. Bentley ◽  
Veronica E. Vleck ◽  
Gregoire P. Millet
Keyword(s):  
Power Output ◽  
Average Power ◽  
Time Trial ◽  
Mechanical Efficiency ◽  
Incremental Test ◽  
Long Duration ◽  
Average Power Output ◽  
And Performance ◽  
The Relationship

The purpose of this study was to determine the relationship between the isocapnic buffer (βisocapnic) and hypocapnic hyperventilation (HHV) phases as well as performance in a short (20-min) and long (90-min) time trial (TT) in trained athletes. In addition, gross (GE, %) and delta (ΔE, %) efficiency were calculated and the relationship between these variables and the average power output (W) in each TT was determined. Thirteen male endurance athletes (Mean ± SD age 31 ± 6 yrs; body mass 75.6 ± 6.3 kg; height 185 ± 6 cm) completed a continuous incremental test to exhaustion for determination of the βisocapnic and HHV phases. A second submaximal test was used to determine GE and ΔE. The average power output (W) was measured in a 20-min and 90-min cycling TT. The βisocapnic phase (W) was significantly correlated to the average power output (W) in the 20-min TT (r = 0.58; p <  0.05), but not in the 90-min TT (r = 0.28). The HHV phase (W) was not significantly correlated to the average power output in the 20-min or 90-min TT. No significant correlation was found for GE or for ΔE and performance in the TT. The data from this study shows that βisocapnic together with HHV is not likely to be a useful indicator of cycle TT performance of 20- to 90-min duration. Furthermore, GE and ΔE determined from a submaximal incremental stepwise test are not related to cycling TT performance of different duration. Key words: incremental, correlation, metabolism, athletes, fatigue

scholarly journals Caffeine Ingestion Does Not Alter Performance during a 100-km Cycling Time-Trial Performance

2002 ◽  
Vol 12 (4) ◽  
pp. 438-452 ◽  
Author(s):  
Angus M. Hunter ◽  
Allan St ◽  
Clair Gibson ◽  
Malcolm Collins ◽  
Mike Lambert ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Average Power ◽  
Time Trial ◽  
Peripheral Fatigue ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Caffeine Ingestion ◽  
Cycling Time Trial ◽  
Time To Completion ◽  
Cycling Time

This study analyzed the effect of caffeine ingestion on performance during a repeated-measures, 100-km, laboratory cycling time trial that included bouts of 1- and 4-km high intensity epochs (HIE). Eight highly trained cyclists participated in 3 separate trials—placebo ingestion before exercise with a placebo carbohydrate solution and placebo tablets during exercise (Pl), or placebo ingestion before exercise with a 7% carbohydrate drink and placebo tablets during exercise (Cho), or caffeine tablet ingestion before and during exercise with 7% carbohydrate (Caf). Placebo (twice) or 6 mg · kg−1 caffeine was ingested 60 min prior to starting 1 of the 3 cycling trials, during which subjects ingested either additional placebos or a caffeine maintenance dose of 0.33 mg · kg−1 every 15 min to trial completion. The 100-km time trial consisted of five 1-km HIE after 10, 32, 52, 72, and 99 km, as well as four 4-km HIE after 20, 40, 60, and 80 km. Subjects were instructed to complete the time trial and all HIE as fast as possible. Plasma (caffeine) was significantly higher during Caf (0.43 ± 0.56 and 1.11 ± 1.78 mM pre vs. post Pl; and 47.32 ± 12.01 and 72.43 ± 29.08 mM pre vs. post Caf). Average power, HIE time to completion, and 100-km time to completion were not different between trials. Mean heart rates during both the 1-km HIE (184.0 ± 9.8 Caf; 177.0 ± 5.8 Pl; 177.4 ± 8.9 Cho) and 4-km HIE (181.7 ± 5.7 Caf; 174.3 ± 7.2 Pl; 175.6 ± 7.6 Cho; p < .05) was higher in Caf than in the other groups. No significant differences were found between groups for either EMG amplitude (IEMG) or mean power frequency spectrum (MPFS). IEMG activity and performance were not different between groups but were both higher in the 1-km HIE, indicating the absence of peripheral fatigue and the presence of a centrally-regulated pacing strategy that is not altered by caffeine ingestion. Caffeine may be without ergogenic benefit during endurance exercise in which the athlete begins exercise with a defined, predetermined goal measured as speed or distance.

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