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  • Author: Frederic Grappe x
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William Bertucci, Frederic Grappe and Alain Groslambert

The aim of our study was to compare crank torque profile and perceived exertion between the Monark ergometer (818 E) and two outdoor cycling conditions: level ground and uphill road cycling. Seven male cyclists performed seven tests in seated position at different pedaling cadences: (a) in the laboratory at 60, 80, and 100 rpm; (b) on level terrain at 80 and 100 rpm; and (c) on uphill terrain (9.25% grade) at 60 and 80 rpm. The cyclists exercised for 1 min at their maximal aerobic power. The Monark ergometer and the bicycle were equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (N⋅m), pedaling cadence (rpm), and cycling velocity (km⋅h−1). The most important findings of this study indicate that at maximal aerobic power the crank torque profiles in the Monark ergometer (818 E) were significantly different (especially on dead points of the crank cycle) and generate a higher perceived exertion compared with road cycling conditions.

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Theo Ouvrard, Alain Groslambert and Frederic Grappe

Recent psychophysiological models of endurance performance explained that pacing strategies and exercise-intensity regulation influence cyclists’ ability to produce high mean power output (PO) during time trials (TTs). However, the relationships between these pacing strategies and psychological parameters of the athletes remain unknown. Purpose: To determine the impact of pacing strategies on cyclists’ mean PO during an elite TT championship and to identify the relationships between these pacing strategies and psychological parameters. Methods: Mean PO, projected frontal area, attentional focus, and pleasure were recorded for 9 male cyclists during an official individual TT national championship. Pacing regulations were quantified from PO using the new exposure variation analysis, which determines times spent at adapted PO for optimal constant-pacing strategy (APO) and inaccurate PO for optimal constant-pacing strategy (IPO). Relationships between mean PO, times spent at APO and IPO, and psychological variables were analyzed. Results: Significant relationships were found between mean PO and exposure variation analysis pacing parameters (r 2 .56–.86, P > .05). Time spent at IPO was negatively related to pleasure during the individual TT (r = −.746, P = .016). Conversely, time spent at APO was significantly related to cyclists’ attentional focus (r = .827, P = .006). Conclusions: Mean PO during elite individual TTs is directly related to athletes’ ability to optimally regulate pace throughout the event. This pacing regulation is influenced by attentional focus and pleasure, underlining that coaches and athletes should devote greater attention to these psychological parameters to improve their performances.

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Grégoire P. Millet, Cyrille Tronche and Frédéric Grappe

Purpose:

To use measurement by cycling power meters (Pmes) to evaluate the accuracy of commonly used models for estimating uphill cycling power (Pest). Experiments were designed to explore the influence of wind speed and steepness of climb on accuracy of Pest. The authors hypothesized that the random error in Pest would be largely influenced by the windy conditions, the bias would be diminished in steeper climbs, and windy conditions would induce larger bias in Pest.

Methods:

Sixteen well-trained cyclists performed 15 uphill-cycling trials (range: length 1.3–6.3 km, slope 4.4–10.7%) in a random order. Trials included different riding position in a group (lead or follow) and different wind speeds. Pmes was quantified using a power meter, and Pest was calculated with a methodology used by journalists reporting on the Tour de France.

Results:

Overall, the difference between Pmes and Pest was –0.95% (95%CI: –10.4%, +8.5%) for all trials and 0.24% (–6.1%, +6.6%) in conditions without wind (>2 m/s). The relationship between percent slope and the error between Pest and Pmes were considered trivial.

Conclusions:

Aerodynamic drag (affected by wind velocity and orientation, frontal area, drafting, and speed) is the most confounding factor. The mean estimated values are close to the power-output values measured by power meters, but the random error is between ±6% and ±10%. Moreover, at the power outputs (>400 W) produced by professional riders, this error is likely to be higher. This observation calls into question the validity of releasing individual values without reporting the range of random errors.

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Sébastien Duc, Vincent Villerius, William Bertucci and Frédéric Grappe

Purpose:

The Ergomo®Pro (EP) is a power meter that measures power output (PO) during outdoor and indoor cycling via 2 optoelectronic sensors located in the bottom bracket axis. The aim of this study was to determine the validity and the reproducibility of the EP compared with the SRM crank set and Powertap hub (PT).

Method:

The validity of the EP was tested in the laboratory during 8 submaximal incremental tests (PO: 100 to 400 W), eight 30-min submaximal constant-power tests (PO = 180 W), and 8 sprint tests (PO > 750 W) and in the field during 8 training sessions (time: 181 ± 73 min; PO: ~140 to 150 W). The reproducibility was assessed by calculating the coefficient of PO variation (CV) during the submaximal incremental and constant tests.

Results:

The EP provided a significantly higher PO than the SRM and PT during the submaximal incremental test: The mean PO differences were +6.3% ± 2.5% and +11.1% ± 2.1%, respectively. The difference was greater during field training sessions (+12.0% ± 5.7% and +16.5% ± 5.9%) but lower during sprint tests (+1.6% ± 2.5% and +3.2% ± 2.7%). The reproducibility of the EP is lower than those of the SRM and PT (CV = 4.1% ± 1.8%, 1.9% ± 0.4%, and 2.1% ± 0.8%, respectively).

Conclusions:

The EP power meter appears less valid and reliable than the SRM and PT systems.

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Anthony Bouillod, Julien Pinot, Flavien Soenen, Theo Ouvrard and Frederic Grappe

Purpose:

To analyze the effect of the pedaling activity in different 4-min time trials (TT4s) (laboratory and field conditions) and compare TT4 and maximal aerobic power (MAP) determined from the classical incremental exercise test in laboratory. It was hypothesized that the exercises performed on the field would determine higher physical (power output [PO]) and mental involvements due to different environmental conditions.

Methods:

Sixteen male cyclists underwent an incremental test to exhaustion and 3 TT4s under different conditions: cycle ergometer (CE), level ground (LG), and uphill (UP).

Results:

Correlation was observed for PO with a trivial effect size and narrow limits of agreement between MAP and CE TT4 (r = .96, P < .001). The comparison between the CE, LG, and UP tests indicates that PO was significantly higher in UP than in CE (+8.0%, P < .001) and LG (+11.0%, P < .001).

Conclusions:

The results suggest that PO depends on the nature of the pedaling activity. Moreover, PO under CE TT4 is a relevant predictor of MAP. It seems important to measure MAP by taking into account the cycling conditions, considering that coaches and scientists use this parameter to assess the aerobic potential of athletes and determine the exercise intensities useful for monitoring adaptation to training.

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William M. Bertucci, Andrew C. Betik, Sebastien Duc and Frederic Grappe

This study was designed to examine the biomechanical and physiological responses between cycling on the Axiom stationary ergometer (Axiom, Elite, Fontaniva, Italy) vs. field conditions for both uphill and level ground cycling. Nine cyclists performed cycling bouts in the laboratory on an Axiom stationary ergometer and on their personal road bikes in actual road cycling conditions in the field with three pedaling cadences during uphill and level cycling. Gross efficiency and cycling economy were lower (–10%) for the Axiom stationary ergometer compared with the field. The preferred pedaling cadence was higher for the Axiom stationary ergometer conditions compared with the field conditions only for uphill cycling. Our data suggests that simulated cycling using the Axiom stationary ergometer differs from actual cycling in the field. These results should be taken into account notably for improving the precision of the model of cycling performance, and when it is necessary to compare two cycling test conditions (field/laboratory, using different ergometers).

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Theo Ouvrard, Alain Groslambert, Gilles Ravier, Sidney Grosprêtre, Philippe Gimenez and Frederic Grappe

Purpose: To identify the impact of a leading teammate in front of a cyclist on psychological, physiological, biomechanical, and performance parameters during an uphill maximal effort. Methods: After familiarization, 12 well-trained competitive cyclists completed 2 uphill time trials (UTTs, 2.7 km at 7.4%) in randomized order; that is, 1 performed alone (control condition) and 1 followed a simulated teammate during the entire UTT (leader condition). Performance (UTT time) and mean power output (PO) were recorded for each UTT. For physiological parameters, mean heart rate and postexercise blood lactate concentration were recorded. Psychological parameters (rating of perceived exertion, pleasure, and attentional focus) were collected at the end of each trial. Results: Performance (UTT time) significantly improved by 4.2% (3.1%) in the leader condition, mainly due to drafting decrease of the aerodynamic drag (58% of total performance gains) and higher end spurt (+9.1% [9.1%] of mean PO in the last 10% of the UTT). However, heart rate and postexercise blood lactate concentration were not significantly different between conditions. From a psychological aspect, higher pleasure was observed in the leader condition (+41.1% [51.7%]), but attentional focus was not significantly different. Conclusions: The presence of a leading teammate during uphill cycling had a strong impact on performance, enabling higher speed for the same mean PO and greater end spurt. These results explain why the best teams competing for the general classification of the most prestigious and contested races like the Grand Tours tend to always protect their leader with teammates during decisive ascents.

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Anthony Bouillod, Julien Pinot, Georges Soto-Romero, William Bertucci and Frederic Grappe

A large number of power meters have been produced on the market for nearly 20 y according to user requirements.

Purpose:

To determine the validity, sensitivity, reproducibility, and robustness of the PowerTap (PWT), Stages (STG), and Garmin Vector (VCT) power meters in comparison with the SRM device.

Methods:

A national-level male competitive cyclist completed 3 laboratory cycling tests: a submaximal incremental test, a submaximal 30-min continuous test, and a sprint test. Two additional tests were performed, the first on vibration exposures in the laboratory and the second in the field.

Results:

The VCT provided a significantly lower 5-s power output (PO) during the sprint test with a low gear ratio than the SRM did (–36.9%). The STG PO was significantly lower than the SRM PO in the heavy-exercise-intensity zone (zone 2, –5.1%) and the low part of the severe-intensity zone (zone 3, –4.9%). The VCT PO was significantly lower than the SRM PO only in zone 2 (–4.5%). The STG PO was significantly lower in standing position than in the seated position (–4.4%). The reproducibility of the PWT, STG, and VCT was similar to that of the SRM system. The STG and VCT PO were significantly decreased from a vibration frequency of 48 Hz and 52 Hz, respectively.

Conclusions:

The PWT, STG, and VCT systems appear to be reproducible, but the validity, sensitivity, and robustness of the STG and VCT systems should be treated with some caution according to the conditions of measurement.