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Featured Application: Optimization of performance in time-trial cycling events through the selection of posture while considering comfort. Abstract: Cyclists usually define their posture according to performance and comfort requirements. However, when modifying their posture, cyclists experience a trade-off between these requirements. In this resea...
Contexts in source publication
Context 1
... use of different bicycles could affect the test results (especially power delivery capacity and pressure on contact areas) because the riders would require extensive adaptation periods to other bicycles. Table 2 presents the main characteristics of the bicycles used by each cyclist. The riders performed the tests using standard cycling equipment (i.e., cycling helmet, short sleeve cycling jersey, padded cycling shorts, and clipless pedal shoes). ...Context 2
... aerobars' heights were set at the highest and lowest configurable limits of the bicycle (namely ABh and ABl, respectively). The configurable limits of the aerobars' heights for each bicycle are presented in Table 2. Figure 1 presents the silhouettes of the cyclists in the sagittal plane riding in the tested postures. ...Context 3
... aerobars' heights were set at the highest and lowest configurable limits of the bicycle (namely ABh and ABl, respectively). The configurable limits of the aerobars' heights for each bicycle are presented in Table 2. Figure 1 presents the silhouettes of the cyclists in the sagittal plane riding in the tested postures. ...Citations
... The ever-increasing significance of understanding cycling aerodynamics is represented by the expansion of work produced within the last ten years (Crouch et al. 2017;Blocken 2020, 2021). Multiple engineering approaches have been formulated among teams to reduce the aerodynamic drag, which include: adjusting the position of the cyclist (Defraeye et al. 2010;Giljarhus et al. 2020;Polanco et al. 2020;Wang et al. 2022;Schaffarczyk et al. 2022;Giljarhus et al. 2023), optimizing the geometry of the cycling equipment (Chabroux et al. 2012;Castellini et al. 2020), improving the skinsuit design (Underwood and Jermy 2011;Oggiano et al. 2013;Zheng et al. 2021), and taking specific strategies in drafting or overtaking (Barry et al. 2014;Blocken et al. 2018;Spoelstra et al. 2021;Cantos et al. 2023). The above researches emphasize the importance of understanding fundamental flow physics in enhancing the aerodynamic performance of cyclists. ...
This work investigated the influence of crosswinds and leg positions on the aerodynamics of an articulated cycling mannequin on a track bicycle. Force, wake total pressure and wake velocity measurements were made in a low-speed sports wind tunnel of closed-circuit type. The freestream velocity and wheel speeds were kept at $$15\, \hbox {m/s}$$ 15 m/s . The crank angle of the mannequin was varied across a pedal cycle. Yaw angles from $$0^{\circ }$$ 0 ∘ to $$20^{\circ }$$ 20 ∘ were examined. The experimental results reveal that the leg position significantly affects the aerodynamic performance of a cyclist. At high yaw angles, the aerodynamic drag on the cyclist showed noticeable deviations between most leg positions and their $$180^{\circ }$$ 180 ∘ -apart pairs. A wake analysis technique effectively captured the influence of leg positions on drag. The total pressure deficit contributes dominantly to the overall drag. The wake pressure contours demonstrate how leg-wheel interaction affects the total pressure distribution and drag under crosswinds. This study offers valuable insights into the flow behavior and drag generation around a cyclist with varying leg positions under crosswinds.
... These data show, acutely at least, that there is a physiological cost of manipulating a rider's position on a time trial bike which may impact on performance. Importantly, our data reflects previous work showing a large variation (− 5 to − 17%) in the change in measured power output during a 20 km TT is experienced following severe acute positional changes [22]. On an individual level, these data confirm that there is no 'one-size fits all' approach that can be taken for aerodynamic optimisation and performance. ...
... Therefore, the difference in the required power to overcome aerodynamic drag was assumed to correspond to a change in power that was translatable to a corresponding change in velocity and projected time. However, it is acknowledged that this may not be the case for all riders, and factors such as comfort and/or flexibility may impact power output [22]. The model assumed no kinetic or potential energy changes as all calculations were based on steady state riding with minimal changes to acceleration. ...
Cycling time trials are characterised by riders adopting positions to lessen the impact of aerodynamic drag. Aerodynamic positions likely impact the power a rider is able to produce due to changes in oxygen consumption, blood flow, muscle activation and economy. Therefore, the gain from optimising aerodynamics must outweigh the potential physiological cost. The aim was to establish the relationship between energy expenditure and aerodynamic drag, with a secondary aim to determine the reliability of a commercially available handlebar mounted aero device for measuring aerodynamic drag. Nine trained male cyclists volunteered for the study. They completed 4 × 3200 m on an outdoor velodrome where stack height was adjusted in 1 cm integers. The drag coefficient ( C d A ), oxygen consumption and aerodynamic-physiological economy (APE) were determined at each stack height, with data used to model 40 km TT performance. Small to moderate effect sizes (ES) in response to stack height change were found for C d A , APE and energy cost. The change in TT time was correlated to ∆aerodynamic drag and ∆APE. Meaningful impacts of change in stack height on C d A , APE, energy cost and predicted TT performance, are apparent with highly individualised responses to positional changes.
... Taken together, these findings suggest that all stakeholders in triathlon believe that the compared to those who reported feeling more comfortable (Polanco et al., 2020). This suggests that for 338 cyclists to take advantage of drag reductions provided by aerodynamic cycling positions, they must 339 spend time training to adopt these postures. ...
Purpose
The purpose of this research was to investigate the beliefs, attitudes, and experiences of stakeholders in youth triathlon regarding the important motor subskills that are required to be successful at the elite level of triathlon competition.
Method
Twenty-five participants were recruited from five stakeholder groups in triathlon and interviewed via video conference. A constructionist and relativist approach to thematic analysis was used to identify three first order themes and several second order themes.
Results
The first, first order theme was ‘Continuous motor skills' which consisted of the invariant features of triathlon's continuous motor skills and the parameterization of continuous motor skills. The second, first order theme was ‘Discrete Motor Skills' and consisted of discrete motor skills involved with cornering and change of direction in each discipline and transition phases in triathlon. The final first order theme was ‘Adaptability to continuous and discrete motor skills'.
Conclusion
This research provides a novel and more broad understanding of the beliefs, attitudes, and experiences of stakeholders in triathlon regarding important motor skills that are required to succeed at the elite level of the sport. This novel and broad understanding of important triathlon motor skills has theoretical implications for evaluating triathlon performance with skill acquisition as a primary focus. Additionally, this research is practically important for coaches, administrators, and athletic performance staff who design training programs and pathways for young, developing triathletes.
... This formulation allows finding the race time by solving equation (8), then obtaining the costate variables described in equations (15) and (16), and finally, computing the derivative of the Hamiltonian with respect to the power (i.e., / ). For the third step, an upper boundary is defined to determine the required solving resolution ≤ ...
... His power delivery capacity and mass were registered. The drag area, rolling resistance coefficient, critical power, and anaerobic work capacity were estimated using the method described by Polanco et al. [3,15,16]. The other parameters (i.e., , , , 1 and 2 ) were adopted from the literature [11,12,17,18]. ...
Pacing strategies are used in cycling to optimize the power delivered by the cyclist during a race. Gains in race time have been obtained when using these strategies compared to self-paced approaches. For this reason, this study is focused on revising the effect that the variation of the cyclist's parameters has on the pacing strategy and its results.
A numeric method was used to propose pacing strategies for a cyclist riding on an ascending 3.7 km route with a constant 6.26% road grade. The method was validated and then implemented to study the effect of aerobic and anaerobic power delivery capacity, mass, and drag area on the pacing strategies and their corresponding estimated race times.
The results showed that modifying 1% of the aerobic capacity or cyclist mass value led to a change of 1% on the race time. Modifying 1% the anaerobic capacity and the drag area led to changes of 0.03% and 0.02% on the race time, respectively. These results are strongly dependent on the route characteristics.
It was concluded that for the studied route (constantly ascending), the variation of the cyclist's aerobic capacity influences the pacing strategy (i.e., the power delivery over the distance). The anaerobic capacity and mass of the cyclist also influence the pacing strategy to a lesser extent.
Lowering of the upper body to optimize cycling time trial (TT) performance is a balance between the aerodynamic advantage related to a lower frontal area and prospective detrimental physiological effects associated with a reduction of the hip-torso angle. To explore this in elite athletes and across positions relevant for competitive cyclists, we analysed racing positions for world championships [WC] top-10 finishers and 10 national elite TT-cyclists. Subsequently, laboratory studies were completed to evaluate effects on exercise economy, muscle oxygenation and perceived exertion for the national TT-group for their habitual position and compared to standard (4-12-20˚) torso angles. Hence, covering the racing position observed for top-10 WC finishers (positioned from 4-12˚) and the national elite (range 8-18˚). Oxygen calorimetry and near-infrared spectroscopy revealed that there was no difference in overall energy expenditure, delta exercise efficiency or muscle oxygenation across the investigated range of positions. However, rating of perceived exertion was significantly elevated for the lowest position (4˚ torso angle) compared to the rider’s habitual position. This lets us conclude that elite TT-cyclists can acutely adopt to a very low upper body position without compromising exercise economy or muscle oxygenation and some WC-level TT riders have adopted this low (4˚) racing position. However, the elevated perception of exertion with an acute reduction of the torso-hip angle indicates that it presumably requires specific training in the position or factors not related to exercise economy and muscle oxygenation determine if a rider in practice can perform in the very low position.
