Determinants of time trial performance and maximal incremental exercise in highly trained endurance athletes

2011 ◽  
Vol 111 (5) ◽  
pp. 1422-1430 ◽  
Author(s):  
R. A. Jacobs ◽  
P. Rasmussen ◽  
C. Siebenmann ◽  
V. Díaz ◽  
M. Gassmann ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Oxidative Phosphorylation ◽  
Power Output ◽  
Vastus Lateralis ◽  
Average Power ◽  
Time Trial ◽  
Vastus Lateralis Muscle ◽  
Time Trial Performance ◽  
Principal Factors ◽  
Trial Performance

Human endurance performance can be predicted from maximal oxygen consumption (V̇o2max), lactate threshold, and exercise efficiency. These physiological parameters, however, are not wholly exclusive from one another, and their interplay is complex. Accordingly, we sought to identify more specific measurements explaining the range of performance among athletes. Out of 150 separate variables we identified 10 principal factors responsible for hematological, cardiovascular, respiratory, musculoskeletal, and neurological variation in 16 highly trained cyclists. These principal factors were then correlated with a 26-km time trial and test of maximal incremental power output. Average power output during the 26-km time trial was attributed to, in order of importance, oxidative phosphorylation capacity of the vastus lateralis muscle ( P = 0.0005), steady-state submaximal blood lactate concentrations ( P = 0.0017), and maximal leg oxygenation (sO2LEG) ( P = 0.0295), accounting for 78% of the variation in time trial performance. Variability in maximal power output, on the other hand, was attributed to total body hemoglobin mass (Hbmass; P = 0.0038), V̇o2max ( P = 0.0213), and sO2LEG ( P = 0.0463). In conclusion, 1) skeletal muscle oxidative capacity is the primary predictor of time trial performance in highly trained cyclists; 2) the strongest predictor for maximal incremental power output is Hbmass; and 3) overall exercise performance (time trial performance + maximal incremental power output) correlates most strongly to measures regarding the capability for oxygen transport, high V̇o2max and Hbmass, in addition to measures of oxygen utilization, maximal oxidative phosphorylation, and electron transport system capacities in the skeletal muscle.

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.

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.

Peak power output, the lactate threshold, and time trial performance in cyclists

2001 ◽  
Vol 33 (12) ◽  
pp. 2077-2081 ◽  
Author(s):  
DAVID J. BENTLEY ◽  
LARS R. MCNAUGHTON ◽  
DYLAN THOMPSON ◽  
VERONICA E. VLECK ◽  
ALAN M. BATTERHAM
Keyword(s):  
Power Output ◽  
Lactate Threshold ◽  
Peak Power ◽  
Time Trial ◽  
Peak Power Output ◽  
Time Trial Performance ◽  
Trial Performance

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.

Time-Trial Performance in Elite Speed Skaters After Remote Ischemic Preconditioning

2018 ◽  
Vol 13 (10) ◽  
pp. 1308-1316 ◽  
Author(s):  
Philippe Richard ◽  
François Billaut
Keyword(s):  
Ischemic Preconditioning ◽  
Saturation Index ◽  
Time Trial ◽  
Remote Ischemic Preconditioning ◽  
Vastus Lateralis Muscle ◽  
Time Trial Performance ◽  
Speed Skating ◽  
Total Hemoglobin ◽  
The Right ◽  
Trial Performance

Purpose: Speed skating leads to blood-flow restriction and deoxygenation in the lower limbs (especially the right leg) that may affect performance. Although the acute influence of such deoxygenation is not clearly understood, the authors tested whether remote ischemic preconditioning (RIPC) could modify muscular oxygenation and improve time-trial performance in that sport. Methods: Using a randomized, single-blind, placebo-controlled, crossover design, 9 elite speed skaters performed 1000-m on-ice time trials preceded by either RIPC of the upper limbs (3 × 5-min compression/5-min reperfusion cycles at 30 mm Hg >arterial systolic pressure) or placebo treatment (SHAM; 10 mm Hg). Changes in tissue saturation index, oxyhemoglobin–oxymyoglobin, deoxyhemoglobin–deoxymyoglobin, and total hemoglobin–myoglobin in the right vastus lateralis muscle were monitored using near-infrared spectroscopy (NIRS). Differences between RIPC and SHAM were analyzed using Cohen effect size (ES) ± 90% confidence limits and magnitude-based inferences. Results: Compared with SHAM, RIPC had a negligible effect on performance and NIRS variables. However, in a subgroup of sprinters (n = 5), RIPC likely lowered tissue saturation index at the beginning of the time trial (−6.1%; ES = −0.65) and likely increased deoxyhemoglobin–deoxymyoglobin at the beginning (3%; ES = 0.39), middle (2.9%; ES = 0.37), and end of the trial (−2.1%; ES = 0.27). In the middle section of the trial, these metabolic changes were concomitant with a possible increase in total hemoglobin–myoglobin. Conclusion: RIPC has no practical ergogenic impact on 1000-m long-track speed-skating performance in elite athletes. The relevance of using RIPC during training to increase physiological stress in sprinters particularly deserves further investigation.

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