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Husband SP, Wainwright B, Wilson F, Crump D, Mockler D, Carragher P, Nugent F, Simms CK. Cycling position optimisation - a systematic review of the impact of positional changes on biomechanical and physiological factors in cycling. J Sports Sci 2024; 42:1477-1490. [PMID: 39285616 DOI: 10.1080/02640414.2024.2394752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 08/14/2024] [Indexed: 09/26/2024]
Abstract
Bike positional configuration changes strongly affect cycling performance. While consensus has emerged on saddle height optimisation, there is none for the relationship between other bike positional variables and cycling performance. Accordingly, this systematic review examines the effect of all major positional variables on performance in cycling, assessing differences between cycling disciplines and sex where possible. The systematic review, conducted per PRISMA guidelines, searched databases including Embase, Web of Science, Medline, and CINAHL, screening 16,578 studies. Of these, 47 were fully analysed. Study quality assessment using the NIH tool revealed none rated "good", 5 "fair" and 33 "poor". The analysis involved 724 participants (90 female, 454 male, 180 sex unstated). Studies focused on trunk angle/upper body position, handlebar height, Q factor, foot position, saddle fore-aft/height, seat tube angle and crank length. Participant cycling disciplines were often unspecified and few papers address women cyclists specifically. Key findings were associated with changing saddle height, trunk angle and saddle fore-aft. For trunk angle, accounting for the biomechanical and physiological effects as well as aerodynamic changes is important. Saddle fore-aft affects the hip angle and trunk angle. There are no clear recommendations for crank length, handlebar height, Q factor or cleat position.
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Affiliation(s)
- Sean Philip Husband
- School of Engineering and Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland
| | | | - Fiona Wilson
- School of Medicine, Trinity College Dublin, Ireland
| | - Danielle Crump
- School of Health and Social Care, University of Lincoln, Lincoln, UK
| | | | - Paul Carragher
- Department of Physiotherapy, Sport Ireland Institute, Dublin, Ireland
| | - Frank Nugent
- Department of Physical Education & Sport Sciences, University of Limerick, Lmerick, Ireland
| | - Ciaran Knut Simms
- School of Engineering and Centre for Biomedical Engineering, Trinity College Dublin, Dublin, Ireland
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2
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Spurrier S, Allen T, Grant RA. Investigating Foot Morphology in Rock Climbing Mammals: Inspiration for Biomimetic Climbing Shoes. Biomimetics (Basel) 2022; 8:biomimetics8010008. [PMID: 36648794 PMCID: PMC9844278 DOI: 10.3390/biomimetics8010008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/19/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
The sporting goods sector can serve as a proving ground for new technologies. We propose that climbing shoes are an excellent case study for showcasing a systematic approach to bio-inspired design. Foot adaptations to climbing have been described before in some animals and have even been incorporated into bio-inspired products. However, there has not yet been a systematic description of climbing adaptations in mammals, and especially in rock climbing species. We present a description of foot morphology in mammals and compare rock climbing species to those with other locomotion types. Our results show that rock climbing species in our sample had fewer digits and larger anterior pads than arboreal species. Rock climbing species often had hooves or, if they had foot pads, these were relatively smooth. These examples look a bit like current climbing shoe designs, perhaps suggesting convergent evolution. However, there was also variation, with rock climbing species having pads varying in shape, placement and texture. Much of this variation is likely to be dependent on the relatedness of species, with those that are more related having more similar feet. We suggest that incorporation of novel textures and compliant pads might be an interesting focus for future climbing shoe designs.
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3
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Jolicoeur Desroches A, Goulet EDB. Is a sub 7-h Ironman TM possible? Front Sports Act Living 2022; 4:866599. [PMID: 36091871 PMCID: PMC9453846 DOI: 10.3389/fspor.2022.866599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/19/2022] [Indexed: 12/03/2022] Open
Affiliation(s)
| | - Eric D. B. Goulet
- Faculty of physical activity sciences, University of Sherbrooke, Sherbrooke, QC, Canada
- Research Centre on Aging, University of Sherbrooke, Sherbrooke, QC, Canada
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Lasshofer M, Seifert J, Wörndle AM, Stöggl T. Heel riser height and slope gradient influence the kinematics and kinetics of ski mountaineering—A laboratory study. Front Sports Act Living 2022; 4:886025. [PMID: 36060627 PMCID: PMC9433713 DOI: 10.3389/fspor.2022.886025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/29/2022] [Indexed: 11/13/2022] Open
Abstract
In ski mountaineering, equipment and its interaction with the exercising human plays an important role. The binding, as the crucial connection between boot and ski, must ensure safe fixation during downhill skiing and a free moving heel when walking uphill. Uphill, the binding offers the possibility to adopt the height of the heel (riser height) to personal preferences and the steepness of the ascent. This possible adjustment and its influence on various biomechanical parameters are the focus of this work. For this study, 19 male leisure ski mountaineers were tested on a treadmill, ascending at a fixed submaximal speed (3.9 ± 0.4 km·h−1) at 8, 16, and 24% gradient and with three heel riser heights, low (0 cm), medium (3.0 cm) and high (5.3 cm). The applied biomechanical measurement systems included a 3D motion capture system in sagittal plane, pressure insoles, a with strain gauges instrumented pole, spirometry and a comfort scale. Step length and step frequency were influenced by the riser height and the gradient (p ≤ 0.001). The high riser height decreased the step length by 5% compared to the low riser height over all tested gradients, while steps were 9.2% longer at the 24% gradient compared to the 8% gradient over all three riser heights. The high riser height revealed a force impulse of the pole 13% lower than using the low riser height (p < 0.001). Additionally, the high riser height reduced the range of motion of the knee joint and the ankle joint compared to the low riser height (p < 0.001). Therefore, advantageous settings can be derived, with the low riser height creating proper range of motion for ankle, knee and hip joint and higher propulsion via the pole at 8%, while higher riser heights like the medium setting do so at steeper gradients. These findings are in line with the conducted comfort scale. We would not recommend the highest riser height for the analyzed gradients in this study, but it might be an appropriate choice for higher gradients.
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Affiliation(s)
- Michael Lasshofer
- Department of Sport and Exercise Science, University of Salzburg, Hallein, Austria
- *Correspondence: Michael Lasshofer
| | - John Seifert
- Department of Sport and Exercise Science, University of Salzburg, Hallein, Austria
- Department of Health & Human Development, Montana State University, Bozeman, MT, United States
| | - Anna-Maria Wörndle
- Department of Sport and Exercise Science, University of Salzburg, Hallein, Austria
| | - Thomas Stöggl
- Department of Sport and Exercise Science, University of Salzburg, Hallein, Austria
- Red Bull Athlete Performance Center, Salzburg, Austria
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5
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Measurements of roll, steering, and the far-field wake in track cycling. Sci Rep 2022; 12:11356. [PMID: 35790801 PMCID: PMC9256602 DOI: 10.1038/s41598-022-15384-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 06/23/2022] [Indexed: 11/08/2022] Open
Abstract
A series of measurements taken with two instrumented track bicycles in a velodrome are presented. The bicycle wheel speed, cadence, roll angle, steering angle, power, and airspeed are recorded. The experimentally-measured values are compared to existing theoretical models of roll and steering angles. The accuracy of the roll angle calculations is dependent on the fidelity of the modelled cyclist path and decreases for higher riding speeds. Experimental measurements of the steering angle show a reasonable agreement to theoretical calculations, albeit with reduced steering angles on the bends at higher speeds. There is also seen an increasing steering angle oscillation within each pedal cycle with increasing bicycle velocity which may influence a cyclist’s rolling resistance and the aerodynamic flow around the bicycle’s front end. Observations are made of changes in the flow field ahead of the bicycle due to the presence of other riders on the track, showing an effective tailwind of up to 0.7 m/s. The measured power shows a decrease at the bend entry due to the changing roll angle. Data presented in this paper provides new insights and can help to provide a validation of values used in existing track cycling analytic models.
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6
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Ghasemi M, Curnier D, Caru M, Trépanier JY, Périé D. The effect of different aero handlebar positions on aerodynamic and gas exchange variables. J Biomech 2022; 139:111128. [DOI: 10.1016/j.jbiomech.2022.111128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/01/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022]
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Abstract
Triathlon is an increasingly popular sport that includes swimming, cycling, followed by running. The triathlete should not be seen merely as a cyclist who also swims and runs. Notable differences are seen in the type of bike used, training patterns, lower extremity demands, and cumulative nature of the sport. Injury prevention and treatment strategies need to take into account the triathlon distance, the type of bike used, athletic experience, prior injuries, risk factors, and a thorough understanding of the demands placed on the body through all 3 disciplines (swim, bike, and run).
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Affiliation(s)
- Daniel M Cushman
- Division of Physical Medicine and Rehabilitation, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA.
| | - Nathan Dowling
- Department of Physical Therapy, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA
| | - Meredith Ehn
- Division of Physical Medicine and Rehabilitation, University of Utah, 590 Wakara Way, Salt Lake City, UT 84108, USA
| | - Dana H Kotler
- Department of Physical Medicine and Rehabilitation, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
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Zignoli A, Biral F, Fornasiero A, Sanders D, Erp TV, Mateo-March M, Fontana FY, Artuso P, Menaspà P, Quod M, Giorgi A, Laursen PB. Assessment of bike handling during cycling individual time trials with a novel analytical technique adapted from motorcycle racing. Eur J Sport Sci 2021; 22:1355-1363. [PMID: 34369299 DOI: 10.1080/17461391.2021.1966517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A methodology to study bike handling of cyclists during individual time trials (ITT) is presented. Lateral and longitudinal accelerations were estimated from GPS data of professional cyclists (n=53) racing in two ITT of different length and technical content. Acceleration points were plotted on a plot (g-g diagram) and they were enclosed in an ellipse. A correlation analysis was conducted between the area of the ellipse and the final ITT ranking. It was hypothesized that a larger area was associated to a better performance. An analytical model for the bike-cyclist system dynamics was used to conduct a parametric analysis on the influence of riding position on the shape of the g-g diagram. A moderate (n=27, r=-0.40, p=0.038) and a very large (n=26, r=-0.83, p<0.0001) association were found between the area of the enclosing ellipse and the final ranking in the two ITT. Interestingly, this association was larger in the shorter race with higher technical content. The analytical model suggested that maximal decelerations are highly influenced by the cycling position, road slope and speed. This investigation, for the first time, explores a novel methodology that can provide insights into bike handling, a large unexplored area of cycling performance.
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Affiliation(s)
- Andrea Zignoli
- Department of Industrial Engineering, University of Trento, Trento, Italy.,Prom Facility, Trentino Sviluppo, Trento, Italy.,CeRiSM Research Centre, University of Verona, Trento, Italy
| | - Francesco Biral
- Department of Industrial Engineering, University of Trento, Trento, Italy
| | | | - Dajo Sanders
- Department of Human Movement Science, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, Netherlands
| | - Teun Van Erp
- Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Manuel Mateo-March
- Spanish Cycling Federation, Madrid, Spain.,Movistar Team, Abarca Sports, Pamplona, Spain
| | | | | | - Paolo Menaspà
- School of Medical and Health Sciences, Edith Cowan University, Perth, Australia
| | - Marc Quod
- Mitchelton-Scott Cycling Team, Adelaide, Australia
| | - Andrea Giorgi
- Androni Giocattoli-Sidermec Professional Cycling Team, Medical Staff, Italy.,Internal Medicine, Specialists Medicine and Rehabilitation Department. Functional Recovery and Re-education Unit. USL Toscana south-east
| | - Paul B Laursen
- Sport Performance Research Institute New Zealand (SPRINZ), Auckland University of Technology, Auckland, New Zealand
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9
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Maximal muscular power: lessons from sprint cycling. SPORTS MEDICINE-OPEN 2021; 7:48. [PMID: 34268627 PMCID: PMC8282832 DOI: 10.1186/s40798-021-00341-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/29/2021] [Indexed: 02/07/2023]
Abstract
Maximal muscular power production is of fundamental importance to human functional capacity and feats of performance. Here, we present a synthesis of literature pertaining to physiological systems that limit maximal muscular power during cyclic actions characteristic of locomotor behaviours, and how they adapt to training. Maximal, cyclic muscular power is known to be the main determinant of sprint cycling performance, and therefore we present this synthesis in the context of sprint cycling. Cyclical power is interactively constrained by force-velocity properties (i.e. maximum force and maximum shortening velocity), activation-relaxation kinetics and muscle coordination across the continuum of cycle frequencies, with the relative influence of each factor being frequency dependent. Muscle cross-sectional area and fibre composition appear to be the most prominent properties influencing maximal muscular power and the power-frequency relationship. Due to the role of muscle fibre composition in determining maximum shortening velocity and activation-relaxation kinetics, it remains unclear how improvable these properties are with training. Increases in maximal muscular power may therefore arise primarily from improvements in maximum force production and neuromuscular coordination via appropriate training. Because maximal efforts may need to be sustained for ~15-60 s within sprint cycling competition, the ability to attenuate fatigue-related power loss is also critical to performance. Within this context, the fatigued state is characterised by impairments in force-velocity properties and activation-relaxation kinetics. A suppression and leftward shift of the power-frequency relationship is subsequently observed. It is not clear if rates of power loss can be improved with training, even in the presence adaptations associated with fatigue-resistance. Increasing maximum power may be most efficacious for improving sustained power during brief maximal efforts, although the inclusion of sprint interval training likely remains beneficial. Therefore, evidence from sprint cycling indicates that brief maximal muscular power production under cyclical conditions can be readily improved via appropriate training, with direct implications for sprint cycling as well as other athletic and health-related pursuits.
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10
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Blocken B, Gillmeier S, Malizia F, van Druenen T. Impact of a motorcycle on cyclist aerodynamic drag in parallel and staggered arrangements. SPORTS ENGINEERING 2021. [DOI: 10.1007/s12283-021-00344-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
AbstractCycling races contain a multitude of motorcycles for various activities including television broadcasting. During parts of the race, these motorcycles can ride in close proximity of cyclists. Earlier studies focused on the impact of a nearby motorcycle on cyclist drag for in-line arrangements. It was shown that not only a motorcycle in front of a cyclist but also a motorcycle closely behind a cyclist can substantially reduce cyclist drag. However, there appears to be no information in the scientific literature about the impact of the motorcycle on cyclist drag for parallel and staggered arrangements. This paper presents wind tunnel measurements of cyclist drag for 32 different parallel and staggered cyclist-motorcycle arrangements. It is shown that the parallel arrangement leads to a drag increase for the cyclist, in the range of 5 to about 10% for a lateral distance of 2 to 1 m. The staggered arrangement can lead to either a drag increase or a drag decrease, where the latter is about 2% for most positions analyzed. For one of the parallel arrangements, computational fluid dynamics simulations were performed to provide insight into the reasons for the drag increase. A cyclist power model was used to convert the drag changes into potential time gains or losses. Compared to a lone cyclist riding at a speed of 46.8 km/h (13 m/s) on level road in calm weather, the time loss by a drag increase of 10%, 4% and − 2% was 2.16, 0.76 s and − 0.80 s per km, respectively. These time differences are large enough to influence the outcome of cycling races.
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11
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Ferguson HA, Harnish C, Chase JG. Using Field Based Data to Model Sprint Track Cycling Performance. SPORTS MEDICINE - OPEN 2021; 7:20. [PMID: 33725208 PMCID: PMC7966696 DOI: 10.1186/s40798-021-00310-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 02/28/2021] [Indexed: 11/21/2022]
Abstract
Cycling performance models are used to study rider and sport characteristics to better understand performance determinants and optimise competition outcomes. Performance requirements cover the demands of competition a cyclist may encounter, whilst rider attributes are physical, technical and psychological characteristics contributing to performance. Several current models of endurance-cycling enhance understanding of performance in road cycling and track endurance, relying on a supply and demand perspective. However, they have yet to be developed for sprint-cycling, with current athlete preparation, instead relying on measures of peak-power, speed and strength to assess performance and guide training. Peak-power models do not adequately explain the demands of actual competition in events over 15-60 s, let alone, in World-Championship sprint cycling events comprising several rounds to medal finals. Whilst there are no descriptive studies of track-sprint cycling events, we present data from physiological interventions using track cycling and repeated sprint exercise research in multiple sports, to elucidate the demands of performance requiring several maximal sprints over a competition. This review will show physiological and power meter data, illustrating the role of all energy pathways in sprint performance. This understanding highlights the need to focus on the capacity required for a given race and over an event, and therefore the recovery needed for each subsequent race, within and between races, and how optimal pacing can be used to enhance performance. We propose a shift in sprint-cyclist preparation away from training just for peak power, to a more comprehensive model of the actual event demands.
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Affiliation(s)
- Hamish A. Ferguson
- Centre for Bioengineering, Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8140 New Zealand
| | - Chris Harnish
- Department of Exercise Science, College of Health, Mary Baldwin University, Staunton, VA USA
| | - J. Geoffrey Chase
- Centre for Bioengineering, Department of Mechanical Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8140 New Zealand
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12
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Aerodynamics of Cycling Skinsuits Focused on the Surface Shape of the Arms. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11052200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In cycling, air resistance corresponds to 90% of the resistance on the bicycle and cyclist and 70% of this is applied to the body of the cyclist. Despite research on postures that could reduce air resistance, few studies have been conducted on full-body cycling suits. As the aerodynamics of the surface shape of clothing fabric are still unclear, the airflow around cyclists and air resistance were examined using a computational fluid dynamics (CFD) method and wind tunnel experiment. Specifically, in this study, we focused on how different surface shapes of cycling suit fabrics affect air resistance. CFD results indicate that air resistance during a race was high at the head, arms and legs of the cyclist. In the wind tunnel experiment, a cylinder model resembling the arms was used to compare the aerodynamic forces of various fabrics and the results showed that air resistance changed according to the fabric surface shape. Moreover, by changing the fabric shape of the arms of the cycling suits, reduction of air resistance by up to 8% is achievable. These results suggest that offering the most appropriate suit type to each cyclist, considering race conditions, can contribute to further improvement in their performance.
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13
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Abstract
AbstractAerodynamic drag is the main resistive force in cycling at high speeds and on flat terrain. In wind tunnel tests or computational fluid dynamics simulations, the aerodynamic drag of cycling wheels is often investigated isolated from the rest of the bicycle, and sometimes in static rather than rotating conditions. It is not yet clear how these testing and simulating conditions influence the wheel aerodynamic performance and how the inclusion of wheel rotation influences the overall measured or computed cyclist drag. This study presents computational fluid dynamics simulations, validated with wind tunnel tests, that indicate that an isolated static spoked front wheel has a 2.2% larger drag area than the same wheel when rotating, and that a non-isolated static spoked front wheel has a 7.1% larger drag area than its rotating counterpart. However, rotating wheels are also subjected to the rotational moment, which increases the total power required to rotate and translate the wheel compared to static conditions where only translation is considered. The interaction with the bicycle frame and forks lowers the drag area of the front wheel by 8.8% for static and by 12.9% for the rotating condition, compared to the drag area of the isolated wheels. A different flow behavior is also found for static versus rotating wheels: large low-pressure regions develop from the hub for rotating wheels, together with a lower streamwise velocity region inside the circumference of the wheel compared to static wheels. The results are intended to help in the selection of testing/simulating methodologies for cycling spoked wheels.
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Kraemer P, Marro M, Correia H, Salizzoni P. Preliminary study on crosswind aerodynamics for a group of road race cyclists. SN APPLIED SCIENCES 2021. [DOI: 10.1007/s42452-021-04233-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
AbstractUnder crosswind conditions, road cyclists experience an extra drag force and a destabilising lateral force. In these conditions a group of cyclists manages to reorganise its spatial formation to minimise these forces forming an echelon, i.e a diagonal single pace line of riders staggered across the road, a configuration which is markedly different from those adopted in wind-free conditions. To study the effect of the crosswind on drag and lateral forces on the riders we performed wind-tunnel experiments using a scale model cyclist and measuring the forces by means of a load cell. Several configurations with one, two, and four cyclists have been investigated varying yaw angles. Results show that, in a basic 4 rider configuration at a 50 $$^{\circ }$$
∘
yaw angle, a sheltered rider within the echelon experiences less than 30% of the drag of the guttered rider behind the echelon, struggling against the crosswind. Furthermore, we show that an echelon is worth being adopted under crosswind conditions only beyond a 30 $$^{\circ }$$
∘
yaw angle. At this critical 30 $$^{\circ }$$
∘
yaw angle the drag on the guttered rider doubles when the gap to the front group increases from 10 cm to 1 m (in real scale). These results can be of interest in defining road cycling race strategies and they allow some significant configurations to be identified and further investigated in more complex experiments.
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Blocken B, Malizia F, van Druenen T, Gillmeier S. Aerodynamic benefits for a cyclist by drafting behind a motorcycle. SPORTS ENGINEERING 2020. [DOI: 10.1007/s12283-020-00332-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractMotorcycles are present in cycling races for reasons including television broadcasting. During parts of the race, these motorcycles ride in front of individual or groups of cyclists. Concerns have been expressed in the professional cycling community that these motorcycles can provide aerodynamic benefits in terms of drag reduction for the cyclists drafting behind them. However, to the best of our knowledge, no information about the extent of these benefits is present in the scientific literature. Therefore, this paper analyses the potential drag reduction for a cyclist by drafting behind a motorcycle. Wind tunnel measurements and numerical simulations with computational fluid dynamics were performed. It was shown that drafting at separation distances d = 2.64, 10, 30 and 50 m can reduce the drag of the cyclist down to 52, 77, 88 and 93% of that of an isolated cyclist, respectively. A cyclist power model is used to convert these drag reductions into potential time gains. For a non-drafting cyclist at a speed of 54 km/h on level road in calm weather, the time gains by drafting at d = 2.64, 10, 30 and 50 m are 12.7, 5.4, 2.7 and 1.6 s per km, respectively. These time differences can influence the outcome of cycling races. The current rules of the International Cycling Union do not prevent these aerodynamic benefits from occurring in races.
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Forte P, Morais JE, P. Neiva H, Barbosa TM, Marinho DA. The Drag Crisis Phenomenon on an Elite Road Cyclist-A Preliminary Numerical Simulations Analysis in the Aero Position at Different Speeds. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17145003. [PMID: 32664605 PMCID: PMC7399909 DOI: 10.3390/ijerph17145003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 11/18/2022]
Abstract
The drag crisis phenomenon is the drop of drag coefficient (Cd) with increasing Reynolds number (Re) or speed. The aim of this study was to assess the hypothetical drag crisis phenomenon in a sports setting, assessing it in a bicycle–cyclist system. A male elite-level cyclist was recruited for this research and his competition bicycle, helmet, suit, and shoes were used. A three-dimensional (3D) geometry was obtained with a 3D scan with the subject in a static aero position. A domain with 7 m of length, 2.5 m of width and 2.5 m of height was created around the cyclist. The domain was meshed with 42 million elements. Numerical simulations by computer fluid dynamics (CFD) fluent numerical code were conducted at speeds between 1 m/s and 22 m/s, with increments of 1 m/s. The drag coefficient ranged between 0.60 and 0.95 across different speeds and Re. The highest value was observed at 2 m/s (Cd = 0.95) and Re of 3.21 × 105, whereas the lower Cd was noted at 9 m/s (Cd = 0.60) and 9.63 × 105. A drag crisis was noted between 3 m/s and 9 m/s. Pressure Cd ranged from 0.35 to 0.52 and the lowest value was observed at 3 m/s and the highest at 2 m/s. The viscous drag coefficient ranged between 0.15 and 0.43 and presented a trend decreasing from 4 m/s to 22 m/s. Coaches, cyclists, researchers, and support staff must consider that Cd varies with speed and Re, and the bicycle–cyclist dimensions, shape, or form may affect drag and performance estimations. As a conclusion, this preliminary work noted a drag crisis between 3 m/s and 9 m/s in a cyclist in the aero position.
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Affiliation(s)
- Pedro Forte
- Department of Sports, Douro Higher Institute of Educational Sciences, 4560-708 Penafiel, Portugal;
- Department of Sports Sciences and Physical Education, Instituto Politécnico de Bragança, 5300-253 Bragança, Portugal;
- Research Center in Sports, Health and Human Development, CIDESD, 6201-001 Covilhã, Portugal; (H.P.N.); (D.A.M.)
- Correspondence: ; Tel.: +351-255-318-550
| | - Jorge E. Morais
- Department of Sports, Douro Higher Institute of Educational Sciences, 4560-708 Penafiel, Portugal;
- Department of Sports Sciences and Physical Education, Instituto Politécnico de Bragança, 5300-253 Bragança, Portugal;
- Research Center in Sports, Health and Human Development, CIDESD, 6201-001 Covilhã, Portugal; (H.P.N.); (D.A.M.)
| | - Henrique P. Neiva
- Research Center in Sports, Health and Human Development, CIDESD, 6201-001 Covilhã, Portugal; (H.P.N.); (D.A.M.)
- Department of Sports Science, Beira Interior University (UBI), 6201-001 Covilhã, Portugal
| | - Tiago M. Barbosa
- Department of Sports Sciences and Physical Education, Instituto Politécnico de Bragança, 5300-253 Bragança, Portugal;
- Research Center in Sports, Health and Human Development, CIDESD, 6201-001 Covilhã, Portugal; (H.P.N.); (D.A.M.)
| | - Daniel A. Marinho
- Research Center in Sports, Health and Human Development, CIDESD, 6201-001 Covilhã, Portugal; (H.P.N.); (D.A.M.)
- Department of Sports Science, Beira Interior University (UBI), 6201-001 Covilhã, Portugal
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Zignoli A, Biral F. Prediction of pacing and cornering strategies during cycling individual time trials with optimal control. SPORTS ENGINEERING 2020. [DOI: 10.1007/s12283-020-00326-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
The Brachistochrone problem, which describes the curve that carries a particle under gravity in a vertical plane from one height to another in the shortest time, is one of the most famous studies in classical physics. There is a similar problem in track cycling, where a cyclist aims to find the trajectory on the curved sloping surface of a velodrome that results in the minimum lap time. In this paper, we extend the classical Brachistochrone problem to find the optimum cycling trajectory in a velodrome, treating the cyclist as an active particle. Starting with two canonical cases of cycling on a sloping plane and a cone, where analytical solutions are found, we then solve the problem numerically on the reconstructed surface of the velodrome in Montigny le Bretonneux, France. Finally, we discuss the parameters of the problem and the effects of fatigue.
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Affiliation(s)
- G. P. Benham
- LadHyX, UMR CNRS 7646, Ecole polytechnique, 91128 Palaiseau, France
| | - C. Cohen
- LadHyX, UMR CNRS 7646, Ecole polytechnique, 91128 Palaiseau, France
| | - E. Brunet
- Fédération Française de Cyclisme, 1 Rue Laurent Fignon, 78180 Montigny-le-Bretonneux, France
| | - C. Clanet
- LadHyX, UMR CNRS 7646, Ecole polytechnique, 91128 Palaiseau, France
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Sitko S, López Laval I, Cirer-Sastre R, Corbi F, Calleja-González J. Physiological demands and characteristics of the participants in a cycling sportive event. J Sports Med Phys Fitness 2019; 60:367-373. [PMID: 31684711 DOI: 10.23736/s0022-4707.19.10196-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Cycling sportives have become increasingly popular in the last years. With over 11,000 participants, the Quebrantahuesos (Qh), is one of the most prominent cycling events in Europe and its ever-growing competitive nature has increased the physiological demands required to obtain a great result. The objectives of the current study were to determine the relationship between the power profile and the result in the event as well as to describe the physiological differences among subgroups of participants according to their result. METHODS Ninety-one male cyclists took part in the study. Data regarding weight, height, experience and training volume were collected before the event. The raw data from the power meter used by the participants during the event's four climbs was sent to the researchers as an Excel file. Participants were then divided in three different groups according to their performance. One-way analysis of variance was performed to assess differences between groups. Pearson's product-moment correlation coefficient was used to assess for associations among performance and/or anthropometric data. RESULTS Group differences were found in body weight (P<0.001), body mass index (P<0.001), training volume (P<0.001) and previous participations in the event (P<0.001). A very high negative correlation between relative power during the climbs and the final time was also observed (r>-0.92; P<0.001). CONCLUSIONS Better performances were associated to lower body weight and body mass index and higher training volume, relative power and experience. The current study provides data that suggest that as long as the average relative power is sustained, the pacing strategy throughout the different climbs does not affect the race outcome. This information could be used by cyclists and coaches when preparing the pacing strategy for the event.
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Affiliation(s)
- Sebastian Sitko
- Faculty of Health and Sport Science, University of Zaragoza, Huesca, Spain
| | - Isaac López Laval
- Faculty of Health and Sport Science, University of Zaragoza, Huesca, Spain -
| | - Rafel Cirer-Sastre
- Institut Nacional d'Educació Física de Catalunya (INEFC), Universitat de Lleida (UdL), Lleida, Spain
| | - Francisco Corbi
- Institut Nacional d'Educació Física de Catalunya (INEFC), Universitat de Lleida (UdL), Lleida, Spain
| | - Julio Calleja-González
- Laboratory of Analysis of Sports Performance, Sport Section, Department of Physical Education and Sport, Faculty of Education, University of the Basque Country (UPV/EHU), Vitoria, Spain
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Blocken B, van Druenen T, Toparlar Y, Andrianne T. CFD analysis of an exceptional cyclist sprint position. SPORTS ENGINEERING 2019. [DOI: 10.1007/s12283-019-0304-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Mannion P, Toparlar Y, Clifford E, Hajdukiewicz M, Andrianne T, Blocken B. The impact of arm-crank position on the drag of a paralympic hand-cyclist. Comput Methods Biomech Biomed Engin 2019; 22:386-395. [DOI: 10.1080/10255842.2018.1558217] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Paul Mannion
- Department of Civil Engineering, College of Engineering and Informatics, National University of Ireland Galway, University Road, Galway, Ireland
- Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands
- Informatics Research Unit for Sustainable Engineering (IRUSE), Galway, Ireland
| | - Yasin Toparlar
- Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Eoghan Clifford
- Department of Civil Engineering, College of Engineering and Informatics, National University of Ireland Galway, University Road, Galway, Ireland
- Informatics Research Unit for Sustainable Engineering (IRUSE), Galway, Ireland
| | - Magdalena Hajdukiewicz
- Department of Civil Engineering, College of Engineering and Informatics, National University of Ireland Galway, University Road, Galway, Ireland
- Informatics Research Unit for Sustainable Engineering (IRUSE), Galway, Ireland
| | - Thomas Andrianne
- Department of Aerospace and Mechanical engineering, University of Liège, Allée de la Découverte, 9 Quartier Polytech 1, Liège, Belgium
| | - Bert Blocken
- Department of the Built Environment, Eindhoven University of Technology, Eindhoven, The Netherlands
- Department of Civil Engineering, Leuven University, Kasteelpark Arenberg 40, Leuven, Belgium
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The variations on the aerodynamics of a world-ranked wheelchair sprinter in the key-moments of the stroke cycle: A numerical simulation analysis. PLoS One 2018; 13:e0193658. [PMID: 29489904 PMCID: PMC5831413 DOI: 10.1371/journal.pone.0193658] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 02/15/2018] [Indexed: 11/19/2022] Open
Abstract
Biomechanics plays an important role helping Paralympic sprinters to excel, having the aerodynamic drag a significant impact on the athlete’s performance. The aim of this study was to assess the aerodynamics in different key-moments of the stroke cycle by Computational Fluid Dynamics. A world-ranked wheelchair sprinter was scanned on the racing wheelchair wearing his competition gear and helmet. The sprinter was scanned in three different positions: (i) catch (hands in the 12h position on the hand-rim); (ii) the release (hands in the 18h position on the hand-rim) and; (iii) recovery phase (hands do not touch the hand-rim and are hyperextended backwards). The simulations were performed at 2.0, 3.5, 5.0 and 6.5 m/s. The mean viscous and pressure drag components, total drag force and effective area were retrieved after running the numerical simulations. The viscous drag ranged from 3.35 N to 2.94 N, pressure drag from 0.38 N to 5.51 N, total drag force from 0.72 N to 8.45 N and effective area from 0.24 to 0.41 m2. The results pointed out that the sprinter was submitted to less drag in the recovery phase, and higher drag in the catch. These findings suggest the importance of keeping an adequate body alignment to avoid an increase in the drag force.
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Improving CFD prediction of drag on Paralympic tandem athletes: influence of grid resolution and turbulence model. SPORTS ENGINEERING 2017. [DOI: 10.1007/s12283-017-0258-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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