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1.
Eur J Appl Physiol ; 123(9): 1991-2000, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37133575

RESUMO

PURPOSE: Time-trial require cyclists to have an acute control on their sensory cues to regulate their pacing strategies. Pacing an effort accurately requires an individual to process sensory signals with efficacy, a factor that can be characterized by a high neural efficiency. This study aimed to investigate the effect of a cycling time-trial on neural efficiency in comparison to a low intensity endurance exercise, the latter supposedly not requiring high sensory control. METHODS: On two separate days, 13 competitive cyclists performed a session comprising of two 10 min treadmill tests, performed at different intensity zones from 1 to 5 on the rating subjective exercise intensity scale. The tests were performed before and after both a time-trial and endurance cycling exercise. Electroencephalography activity was measured during each intensity zones of the treadmill exercises. Neural efficiency was then calculated for each intensity block using the α/ß electroencephalography activity ratio. RESULTS: The neural efficiency averaged on the 5 IZ decreased following the time-trial in the motor cortex (- 13 ± 8%) and prefrontal cortex (- 10 ± 12%), but not after the endurance exercise. CONCLUSION: To conclude, the time-trial impaired the neural efficiency and increasing the RPE of the cyclists in the severe intensity zone.


Assuntos
Exercício Físico , Resistência Física , Humanos , Resistência Física/fisiologia , Exercício Físico/fisiologia , Teste de Esforço , Terapia por Exercício , Ciclismo/fisiologia
2.
Sensors (Basel) ; 22(1)2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35009945

RESUMO

A large number of power meters have become commercially available during the last decades to provide power output (PO) measurement. Some of these power meters were evaluated for validity in the literature. This study aimed to perform a review of the available literature on the validity of cycling power meters. PubMed, SPORTDiscus, and Google Scholar have been explored with PRISMA methodology. A total of 74 studies have been extracted for the reviewing process. Validity is a general quality of the measurement determined by the assessment of different metrological properties: Accuracy, sensitivity, repeatability, reproducibility, and robustness. Accuracy was most often studied from the metrological property (74 studies). Reproducibility was the second most studied (40 studies) property. Finally, repeatability, sensitivity, and robustness were considerably less studied with only 7, 5, and 5 studies, respectively. The SRM power meter is the most used as a gold standard in the studies. Moreover, the number of participants was very different among them, from 0 (when using a calibration rig) to 56 participants. The PO tested was up to 1700 W, whereas the pedalling cadence ranged between 40 and 180 rpm, including submaximal and maximal exercises. Other exercise conditions were tested, such as torque, position, temperature, and vibrations. This review provides some caveats and recommendations when testing the validity of a cycling power meter, including all of the metrological properties (accuracy, sensitivity, repeatability, reproducibility, and robustness) and some exercise conditions (PO range, sprint, pedalling cadence, torque, position, participant, temperature, vibration, and field test).


Assuntos
Ciclismo , Teste de Esforço , Exercício Físico , Humanos , Reprodutibilidade dos Testes , Torque
3.
Appl Psychophysiol Biofeedback ; 46(4): 335-345, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34146186

RESUMO

This study aimed to investigate the relationship between neural efficiency and the ability of an athlete to produce accurate efforts in different perceived intensity zones during a racing scenario. The α/ß ratio was used to quantify the neural efficiency during cycling, as it traduced the degree of participants information processing activity with lower cortical activity possible. Twelve trained competitive male cyclists delimited their perceived intensity zones 2 to 6 on a scale to assess the rating of exercise intensity. Then, they performed a 30 min racing scenario during which they had to produce different perceived intensities. The ability of athletes to produce perceived effort with accuracy and their neural efficiency was quantified during the racing scenario. The increase in the neural efficiency with the increase in the effort intensity could partly explain the improvement in athletes' ability to produce accurately perceived efforts from intensity zones 3 to 6. Moreover, the neural efficiency during the racing scenario was significantly correlated to the ability to produce perceived effort with accuracy at submaximal intensities.


Assuntos
Atletas , Ciclismo , Cognição , Humanos , Masculino , Esforço Físico
4.
J Sports Sci ; 37(3): 291-297, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30020858

RESUMO

The purpose of this study was to analyze the pacing strategy and its affective consequences during self-paced cycling time trials (TT) performed at different severity of hypoxia. Eight competitive cyclists performed five 30 min self-paced TTs at their best performance in the following conditions: 1) normobaric normoxia (NNSL); 2) normobaric hypoxia under two simulated altitudes: 2000 m (NH2000) and 3500 m (NH3500) and 3) normobaric hypoxia but the cyclists were deceived and thought to be at sea level for 2000 m (DecNH2000) and 3500 m (DecNH3500). Power Output (PO), oxygen uptake (VO2), and blood lactate concentration ([La]) were recorded to assess exercise intensity and physiological adaptations. The rate of perceived exertion (RPE) and pleasure were measured with a CR10 Borg scale to evaluate the affective load (AL). PO and VO2 decreased with the severity of hypoxia but no significantly difference on performance was measured between deceived and real conditions, except for pacing strategy. The started intensity depends on the exercise expectations, but PO was rapidly adjusted with the physiological constraints and the rate of increase of RPE. Finally, AL did not reach maximal values so that the athletes sustained a physiological and emotional reserve to perform a final spurt.


Assuntos
Afeto , Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Ciclismo/fisiologia , Ciclismo/psicologia , Retroalimentação Psicológica , Adulto , Altitude , Atletas , Frequência Cardíaca , Humanos , Hipóxia , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio , Esforço Físico , Adulto Jovem
5.
J Sports Sci ; 36(10): 1173-1178, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28776487

RESUMO

Cyclists regularly change from a seated to a standing position when the gradient increases during uphill cycling. The aim of this study was to analyse the physiological and biomechanical responses between seated and standing positions during distance-based uphill time trials in elite cyclists. Thirteen elite cyclists completed two testing sessions that included an incremental-specific cycling test on a cycle ergometer to determine VO2max and three distance-based uphill time trials in the field to determine physiological and biomechanical variables. The change from seated to standing position did not influence physiological variables. However, power output was increased by 12.6% in standing position when compared with seated position, whereas speed was similar between the two positions. That involved a significant increase in mechanical cost and tangential force (Ftang) on the pedal (+19% and +22.4%, respectively) and a decrease (-8%) in the pedalling cadence. Additionally, cyclists spent 22.4% of their time in the standing position during the climbing time trials. Our findings showed that cyclists alternated between seated and standing positions in order to maintain a constant speed by adjusting the balance between pedalling cadence and Ftang.


Assuntos
Ciclismo/fisiologia , Postura/fisiologia , Fenômenos Biomecânicos , Teste de Esforço/métodos , Frequência Cardíaca/fisiologia , Humanos , Consumo de Oxigênio/fisiologia , Troca Gasosa Pulmonar/fisiologia , Volume de Ventilação Pulmonar/fisiologia , Fatores de Tempo , Estudos de Tempo e Movimento , Adulto Jovem
6.
J Strength Cond Res ; 32(12): 3519-3527, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26840438

RESUMO

Ravier, G, Bouzigon, R, Beliard, S, Tordi, N, and Grappe, F. Benefits of compression garments worn during handball-specific circuit on short-term fatigue in professional players. J Strength Cond Res 32(12): 3528-3536, 2018-The purpose of this study was to investigate the benefits of full-leg length compression garments (CGs) worn during a handball-specific circuit exercises on athletic performance and acute fatigue-induced changes in strength and muscle soreness in professional handball players. Eighteen men (mean ± SD: age 23.22 ± 4.97 years; body mass: 82.06 ± 9.69 kg; height: 184.61 ± 4.78 cm) completed 2 identical sessions either wearing regular gym short or CGs in a randomized crossover design. Exercise circuits of explosive activities included 3 periods of 12 minutes of sprints, jumps, and agility drills every 25 seconds. Before, immediately after and 24 hours postexercise, maximal voluntary knee extension (maximal voluntary contraction, MVC), rate of force development (RFD), and muscle soreness were assessed. During the handball-specific circuit sprint and jump performances were unchanged in both conditions. Immediately after performing the circuit exercises MVC, RFD, and PPT decreased significantly compared with preexercise with CGs and noncompression clothes. Decrement was similar in both conditions for RFD (effect size, ES = 0.40) and PPT for the soleus (ES = 0.86). However, wearing CGs attenuated decrement in MVC (p < 0.001) with a smaller decrease (ES = 1.53) in CGs compared with regular gym shorts condition (-5.4 vs. -18.7%, respectively). Full recovery was observed 24 hours postexercise in both conditions for muscle soreness, MVC, and RFD. These findings suggest that wearing CGs during a handball-specific circuit provides benefits on the impairment of the maximal muscle force characteristics and is likely to be worthwhile for handball players involved in activities such as tackles.


Assuntos
Vestuário , Fadiga Muscular , Músculo Esquelético/fisiologia , Mialgia/prevenção & controle , Esportes/fisiologia , Meias de Compressão , Adulto , Desempenho Atlético/fisiologia , Estudos Cross-Over , Humanos , Masculino , Adulto Jovem
7.
J Therm Biol ; 65: 138-144, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28343567

RESUMO

Whole-body cryotherapy (WBC) and partial-body cryotherapy (PBC) are two methods of cold exposure (from -110 to -195°C according to the manufacturers). However, temperature measurement in the cold chamber during a PBC exposure revealed temperatures ranging from -25 to -50°C next to the skin of the subjects (using isolating layer placed between the sensor and the skin). This discrepancy is due to the human body heat transfer. Moreover, on the surface of the body, an air layer called the boundary layer is created during the exposure and limits heat transfer from the body to the cabin air. Incorporating forced convection in a chamber with a participant inside could reduce this boundary layer. The aim of this study was to explore the use of a new WBC technology based on forced convection (frontal unilateral wind) through the measurement of skin temperature. Fifteen individuals performed a 3-min WBC exposure at -40°C with an average wind speed of 2.3ms-1. The subjects wore a headband, a surgical mask, underwear, gloves and slippers. The skin temperature of the participants was measured with a thermal camera just before exposure, just after exposure and at 1, 3, 5, 10, 15 and 20min after exposure. Mean skin temperature significantly dropped by 11°C just after exposure (p<0.001) and then significantly increased during the 20-min post exposure period (p<0.001). No critically low skin temperature was observed at the end of the cold exposure. This decrease was greater than the mean decreases in all the cryosauna devices with reported exposures between -140°C and -160°C and those in two other WBC devices with reported exposures between -60°C and -110°C. The use of this new technology provides the ability to reach decreases in skin temperature similar to other technologies. The new chamber is suitable and relevant for use as a WBC device.


Assuntos
Crioterapia/instrumentação , Adulto , Temperatura Corporal , Temperatura Baixa , Convecção , Crioterapia/métodos , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Temperatura Cutânea , Termografia/instrumentação , Termografia/métodos , Sensação Térmica , Imagem Corporal Total/instrumentação , Imagem Corporal Total/métodos
8.
J Therm Biol ; 61: 67-81, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27712663

RESUMO

Cold therapy is commonly used as a method to relieve pain and inflammation. This review focuses primarily on two methods of cold therapy that have received recent attention: whole-body cryotherapy and partial-body cryotherapy. These methods are used to induce physiological and psychological benefits in humans in the context of medicine, health and sports. The subjects experiencing cryotherapy are dressed in minimal clothing and are exposed to very cold air (at -110°C or less) for 1-4min. Despite the increasing scientific interest in these methods, there is a lack of information about the technologies used. Moreover, there is no existing reference concerning exposure protocols and the relationship between temperature, duration, number of repetitions and the treatments' desired effects. The aim of this review is to compare whole- and partial-body cryotherapy effects (especially on skin temperature) and to classify the protocols for exposure according to the desired effects. This review emphasises 1) the lack of information concerning the actual temperatures inside the cabin or chamber during exposure and 2) the heterogeneity among the exposure protocols that have been reported in the scientific literature. This review will be valuable and relevant to health professionals endeavouring to optimize the cold treatments offered to patients and producers of cryotherapy apparatus striving to create more efficient devices that meet market requirements.


Assuntos
Crioterapia/métodos , Animais , Ansiedade/terapia , Artrite Reumatoide/terapia , Crioterapia/instrumentação , Depressão/terapia , Fibromialgia/terapia , Humanos , Dor Lombar/terapia , Esclerose Múltipla/terapia , Espondilite Anquilosante/terapia
9.
J Sports Sci Med ; 15(2): 223-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27274658

RESUMO

Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg(-1) friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key pointsThe Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring.This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase.This maximal power output improvement was independent from the shoe-pedal linkage condition.Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences.

10.
J Sports Sci ; 33(9): 907-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25357188

RESUMO

This study analysed the evolution of the physical potential of a twice top-10 Grand Tour cycling finisher (Tour de France and Vuelta a España) whose training was monitored between the ages of 18 and 23 years. The world-class cyclist's power output (PO) data and training indices were analysed over six years to determine the evolution of his record power profile and training load (TL), which were estimated by using the session rating of perceived exertion (RPE) method. The total annual duration and TL increased through six seasons by 79% and 83%, respectively. The record POs in all exercise intensity zones improved over the six years. The increases in TL, monotony (+34%) and strain (+162%) from the junior category to the world-class level significantly correlated with an improvement in his aerobic potential, which was characterised by an increase in the record POs between 5 min and 4 h. This case study of the performance level and training parameters of a world-class cyclist provides comprehensive insight into the evolution of a cyclist to the top level. Furthermore, determining the record power profile of this athlete over six competitive seasons illuminates the maturation of the physical potential of a top-10 Grand Tour finisher.


Assuntos
Ciclismo/fisiologia , Comportamento Competitivo/fisiologia , Educação Física e Treinamento/métodos , Resistência Física/fisiologia , Adolescente , Fenômenos Biomecânicos , Humanos , Masculino , Adulto Jovem
11.
J Appl Biomech ; 28(6): 636-44, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22694978

RESUMO

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).


Assuntos
Ciclismo/fisiologia , Ergometria/instrumentação , Ergometria/métodos , Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Análise e Desempenho de Tarefas , Adulto , Humanos , Masculino
12.
Sports Biomech ; 10(3): 197-218, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21936289

RESUMO

When cycling on level ground at a speed greater than 14 m/s, aerodynamic drag is the most important resistive force. About 90% of the total mechanical power output is necessary to overcome it. Aerodynamic drag is mainly affected by the effective frontal area which is the product of the projected frontal area and the coefficient of drag. The effective frontal area represents the position of the cyclist on the bicycle and the aerodynamics of the cyclist-bicycle system in this position. In order to optimise performance, estimation of these parameters is necessary. The aim of this study is to describe and comment on the methods used during the last 30 years for the evaluation of the effective frontal area and the projected frontal area in cycling, in both laboratory and actual conditions. Most of the field methods are not expensive and can be realised with few materials, providing valid results in comparison with the reference method in aerodynamics, the wind tunnel. Finally, knowledge of these parameters can be useful in practice or to create theoretical models of cycling performance.


Assuntos
Ciclismo/fisiologia , Vento , Fenômenos Biomecânicos , Fenômenos Biofísicos/fisiologia , Ergonomia , Humanos , Modelos Lineares , Modelos Teóricos
13.
J Sports Med Phys Fitness ; 59(12): 2030-2039, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31933344

RESUMO

INTRODUCTION: Pedaling technique which can be defined as the way the cyclists pedal, has been mostly studied in lab conditions from pedal force kinetic, joints kinematic, and/or muscular activity patterns because it is considered as a main factor for gross efficiency (GE). Although this method is much controversial, its quality has extensively been evaluated from the index of pedal force effectiveness (IFE), i.e. the ratio between the effective to the total pedal force. Over the last thirty years, preferred pedaling technique has been compared between the experienced cyclists and non-cyclists and also often been manipulated by instructing these subjects to improve their effective force production during the downstroke phase ("pushing"), the upstroke phase ("pulling-up") or around top and bottom dead centers ("circling"). EVIDENCE ACQUISITION: It has been shown that PREF pedaling technique is much repeatable across crank cycles in experienced cyclists than in novice cyclists. PULL involves a significant increase of IFE compared to PREF, mainly attributed to the increase of the muscular work of hip (RF) and knee flexors muscles (BF) during the upstroke. This improvement is larger in non-cyclists than in experienced cyclists but it can be optimized in the latter after a short-term training (2-4 weeks) with pedal force feedback or uncoupled cranks. EVIDENCE SYNTHESIS: Despite that PULL enhances a lower muscular recruitment of contralateral knee extensors, GE and cycling performance variables are not significantly increased, probably due to the reversal effect of training with normal cranks and the highly robust pedaling technique of experienced cyclists. The question arises, as to whether or not, changes in pedaling technique can improve cycling efficiency if enough time is given for cyclists to adapt to a new pedaling technique. CONCLUSIONS: Further studies should investigate the pedaling techniques in more "ecological" conditions, as there is not probably one but several pedaling techniques that could optimize cycling efficiency according to the pedaling conditions (time-trial, uphill, road, off-road and track cycling), and should also focus on the potential effects of long-term training of PULL pedaling technique on cycling efficiency and cycling performance.


Assuntos
Desempenho Atlético , Ciclismo/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Pé/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Músculo Esquelético/fisiologia , Adulto Jovem
14.
Int J Sports Physiol Perform ; 14(4): 451-457, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30204530

RESUMO

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 (r2 .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.


Assuntos
Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Atenção , Ciclismo/fisiologia , Ciclismo/psicologia , Comportamento Competitivo/fisiologia , Prazer , Adulto , Lobo Frontal/fisiologia , Humanos , Masculino , Análise e Desempenho de Tarefas
15.
J Hum Kinet ; 62: 55-63, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29922377

RESUMO

Partial-body cryostimulation is used to improve recovery after exercise, especially during competitions or heavy training; however, a limited number of studies have been conducted with international-level athletes in situ during competitions. This study was undertaken to assess the thermal sensation ratings during 3 min of cold exposure (at -130°C) in 24 international-level athletes during the European Basketball Championship. The mean thermal sensation score, measured using a perceptive scale, increased significantly (p < 0.05) during partial-body cryostimulation exposure in athletes from 3.0 ± 1.7 at 30 s to 5.7 ± 2.3 at 3 min (maximal observed value = 10.0). The mean value of 5.7 is considered a "cold" sensation on the scale (ranging from 0 = neutral sensation to 10 = very cold). However, we observed a large inter-individual variation in the perceived thermal sensations. The body mass index was significantly and negatively correlated with the thermal sensation value after 2 min 30 s and 3 min of exposure in females (r = -0.61, n = 13, p < 0.05; r = -0.56, n = 13, p = 0.054, respectively). Three participants reported high perceived thermal sensation after 30 s of exposure and their cold-induced discomfort worsened as the exposure continued. In conclusion, a 3-min exposure is globally well tolerated by athletes and can be used during a heavy competition period and/or during a training period. However, special attention should be given to female athletes with a low body mass index as they seem to be much more sensitive to cold.

16.
Int J Sports Physiol Perform ; 13(9): 1215-1222, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29651888

RESUMO

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.


Assuntos
Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Ciclismo/fisiologia , Ciclismo/psicologia , Esforço Físico/fisiologia , Movimentos do Ar , Atenção , Fenômenos Biomecânicos , Comportamento Competitivo/fisiologia , Humanos , Masculino , Percepção/fisiologia , Adulto Jovem
17.
J Biomech ; 72: 99-105, 2018 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-29559241

RESUMO

This study was designed to examine the influence of standing position (vs. seated) during uphill cycling on both mechanical cost (MC) and energy cost (EC) in elite cyclists. For the study, thirteen elite cyclists (VO2max: 71.4 ±â€¯8.0 ml·min-1·kg-1) performed, in a randomised order, three sets of exercises. Each set comprised 2 min of exercise, alternating every 30 s between seated and standing postures, using different slopes and intensity levels on a motorised treadmill. MC was calculated from the measurement of power output and speed, whereas EC was calculated from the measurement of oxygen consumption and speed. MC was significantly higher (+4.3%, p < 0.001) in standing position compared to seated position when all slopes and intensities were considered. However, EC was not significantly affected by the change in position. The standing position also induced a significant increase in rolling resistance power (p < 0.001), rolling resistance coefficient (p < 0.001) and lateral sways (p < 0.001). The significant increase in MC observed in standing position was due to a higher rolling resistance induced by bicycle sways and a shift forward of the centre of mass compared to seated position. This result should lead bicycle tire manufacturers to reduce the increase in rolling resistance between the two positions. Considering the relationship observed between the MC and bicycle sways, cyclists would be well advised to decrease the bicycle sways in order to reduce the MC of locomotion.


Assuntos
Ciclismo/fisiologia , Metabolismo Energético , Postura Sentada , Posição Ortostática , Adolescente , Adulto , Teste de Esforço , Humanos , Locomoção/fisiologia , Consumo de Oxigênio , Adulto Jovem
18.
Int J Sports Physiol Perform ; 12(1): 44-49, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27002343

RESUMO

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.


Assuntos
Ciclismo/fisiologia , Meio Ambiente , Teste de Esforço/métodos , Frequência Cardíaca , Humanos , Masculino , Percepção , Condicionamento Físico Humano/métodos , Esforço Físico/fisiologia , Análise e Desempenho de Tarefas , Adulto Jovem
19.
Int J Sports Physiol Perform ; 12(8): 1023-1030, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27967278

RESUMO

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.


Assuntos
Ciclismo/fisiologia , Ergometria/instrumentação , Desenho de Equipamento , Teste de Esforço/instrumentação , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
20.
J Biomech ; 38(5): 1003-10, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15797582

RESUMO

Despite the importance of uphill cycling performance during cycling competitions, there is very little research investigating uphill cycling, particularly concerning field studies. The lack of research is partly due to the difficulties in obtaining data in the field. The aim of this study was to analyse the crank torque in road cycling on level and uphill using different pedalling cadences in the seated position. Seven male cyclists performed four tests in the seated position (1) on level ground at 80 and 100 rpm, and (2) on uphill road cycling (9.25% grade) at 60 and 80 rpm.The cyclists exercised for 1 min at their maximal aerobic power. The bicycle was equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nm), pedalling cadence (rpm), and cycling velocity (km h(-1)). The most important finding of this study indicated that at maximal aerobic power the crank torque profile (relationship between torque and crank angle) varied substantially according to the pedalling cadence and with a minor effect according to the terrain. At the same power output and pedalling cadence (80 rpm) the torque at a 45 degrees crank angle tended (p < 0.06) to be higher (+26%) during uphill cycling compared to level cycling. During uphill cycling at 60 rpm the peak torque was increased by 42% compared with level ground cycling at 100 rpm. When the pedalling cadence was modified, most of the variations in the crank torque profile were localised in the power output sector (45 degrees to 135 degrees).


Assuntos
Ciclismo/fisiologia , Transferência de Energia/fisiologia , Perna (Membro)/fisiologia , Contração Muscular/fisiologia , Resistência Física/fisiologia , Esforço Físico/fisiologia , Desempenho Psicomotor/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Teste de Esforço/métodos , Humanos , Masculino , Torque
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