Pedaling Technique Research Articles

Muscle fatigue, pedalling technique and the slow component during cycling.

Above the first lactate threshold, the steady-state is delayed or prevented due to the slow component ( ). This phenomenon has been associated with muscle fatigue, but evidence for a causal relationship is equivocal. Moreover, little is known about the contribution of pedalling technique adjustments to during fatiguing cycling exercise. Eleven participants completed constant power trials at 10% above the second lactate threshold. Muscle fatigue was assessed, utilizing femoral nerve stimulation and instrumented pedals, while , quadriceps oxygenation, electromyography (EMG) and pedal force components were measured. Correlations between physiological and mechanical variables were estimated at group and individual levels. Group correlations revealed moderate values for with quadriceps twitch force (r=-0.51) and muscle oxygenation (r=-0.52), while weak correlations were observed for EMG amplitude (r=0.26) and EMG mean power frequency (r=-0.16), and with pedalling mechanical variables such as peak total downstroke force (r=-0.16), minimum total upstroke force (r=-0.16) and upstroke index of effectiveness (r=0.16). The findings here align with prior literature reporting significant correlations between the magnitude of muscle fatigue and that of , although there was large interindividual variability for all the reported correlations. Considering the heterogeneity in the data, it is difficult to determine therelative impact of pedalling technique adjustments on overall, but the present study opens the possibility that in some cases, increases in secondary to technical adjustments may be 'superimposed' on the underlying .

Pedal Quadrant-Specific Strength and Conditioning Considerations for Endurance Cyclists

ABSTRACT The performance-enhancing effects of strength training on cycling are well documented with findings from research, demonstrating resistance training with heavy loads conducted 2–3 times per week for at least 8 weeks can improve power output (maximal and submaximal), extend time to exhaustion, and reduce completion time for set distances, while not adding to the total body mass. Despite the evident benefits of strength training, there remains a lack of consensus regarding the most effective exercises to enhance endurance cycling. This uncertainty is evident when considering movement-specific exercises to enhance dynamic transfer to cycling. A range of lower-limb exercises involving hip, knee, and ankle flexion and extension seems to enhance cycling performance more so than static or single-joint exercises. These improvements may be attributed to enhanced coordination and improved pedaling technique. This study presents 5 strength training exercises designed to target cycling pedaling quadrants and replicate the unilateral opposing nature of cycling (simultaneous flexion and extension of the legs) to enhance transfer from weight room-based strength training to the bike. These exercises are presented in example programs alongside established “traditional” exercises that may be used to guide the development of strength training for cyclists.

Limiting radial pedal forces greatly reduces maximal power output and efficiency in sprint cycling: an optimal control study.

A cyclist's performance depends critically on the generated average mechanical power output (AMPO). The instantaneous mechanical power output equals the product of crank angular velocity, crank length, and the tangential pedal force. Radial pedal forces do not contribute to mechanical power. It has been suggested that radial pedal forces arise from suboptimal pedaling technique and that limiting these would increase AMPO and efficiency. Here, we presented an optimal control musculoskeletal model of a cyclist (consisting of five segments driven by nine Hill-type muscle-tendon units) to predict maximal AMPO during sprint cycling at different levels of allowed radial pedal forces. Our findings showed that limiting radial pedal forces has a detrimental effect on maximal AMPO; it dropped from 1,115 W without a limit on radial forces to 528 W when no radial forces were allowed (both at 110 rpm). We explained that avoiding radial pedal forces causes ineffective use of muscles: muscles deliver less positive power and have a higher muscle power dissipation ratio (average mechanical power dissipated per unit of average positive power delivered). We concluded that radial pedal forces are an unavoidable by-product when optimizing for maximal AMPO and that limiting these leads to a performance decrease.NEW & NOTEWORTHY In the literature, but also in the "cycling field" [e.g., trainers, coaches, and (professional) cyclists], it is often suggested that trying to limit/avoid radial pedal forces enhances cycling technique and with that maximal average power output and efficiency. In this paper, we introduce an optimal control model of a human cyclists (consisting of five segments and driven by nine Hill-type muscle-tendon complex models). With that we not only show, but also explain why limiting radial forces is a bad idea: it will decrease maximal attainable AMPO and will decrease efficiency.

A literature overview of modern biomechanical-based technologies for bike-fitting professionals and coaches

The optimization of cycling position is essential to improve performance and prevent overuse injuries. Bike-fitting methods, based on biomechanical variables, have been proposed in the scientific literature. To facilitate and generalize their use, the bike-fitting industry has developed various technologies to study and analyze the cycling position. The vast majority of bike-fitting protocols are based on joint kinematics, which can be evaluated in laboratory with two- or three-dimensional motion analysis systems. Joint kinematics can also be assessed in outdoor conditions with inertial measurement units, but currently, these tools provide a limited number of variables compared to laboratory systems. In addition, the bike-fitting professional can analyse pedalling technique with pedal forces to understand the effects of the bike adjustments on pedalling effectiveness. To complete the biomechanical evaluation, pressure mapping sensors allow for the measurement of the pressure load and distribution on the interfaces between the cyclist and the bicycle to detect imbalances and choose bike components (e.g., saddle). To go further in the analysis, muscular activity can be assessed with surface electromyography sensors to detect imbalances or asymmetry. The aim of this literature overview is to clearly define the role of these technologies in a bike-fitting protocol and identify their characteristics and limitations while proposing perspectives for future developments. Therefore, this work is intended for bike-fitting professionals and coaches wishing to choose the most suitable technologies to study and improve the cycling position, and for the bike-fitting industry, in order to optimize existing technologies and help develop new concepts.

The relationship between pedal force application technique and the ability to perform supramaximal pedaling cadences.

This study aimed to examine the relationship between the pedal force application technique under a specific competitive condition and the ability to perform steady-state pedaling at a supramaximal cadence during a special pedaling test. A total of 15 competitive male cyclists and 13 active, healthy men (novice cyclists, hereafter, novices) performed the pedaling technique test. The test imitated a road cycling competition condition (80% VO2 peak and a cadence of 90 rpm). Additionally, they performed a supramaximal cadence test that evaluated the ability to perform steady-state pedaling for an ultra-high cadence (range of 160–220 rpm) of 30 s stably with a 0.1 kgf. For the pedaling technique test, kinetic data were obtained by the pedal-shaped force platform at 1,000 Hz, and the pedaling technique was determined by the index of force effectiveness (IFE). For the supramaximal cadence test, kinematic data were obtained using a motion capture system at 200 Hz. The supramaximal pedaling cadence (Cmax) was determined by measuring exercise time and targeted pedaling cadence. The IFE was 48.0 ± 9.7% in cyclists and 32.0 ± 5.9% in novices. The Cmax was 215.5 ± 8.8 rpm in cyclists and 192.2 ± 13.0 rpm in novices. These values were significantly higher for cyclists than for novices. Cmax was moderately correlated with IFE (r = 0.64). No significant correlation was observed between Cmax and IFE for cyclists only; in contrast, a moderate correlation was observed between these parameters for novices only (r = 0.67). In conclusion, the pedal force application technique under a specific competitive condition is related to the ability to perform steady-state pedaling for supramaximal cadence during the test. Therefore, Cmax may be able to explain pedal force application techniques without the need for expensive devices for novices.

Possibility to Use Professional Bicycle Computers for the Scientific Evaluation of Electric Bikes: Velocity, Cadence and Power Data

The aim of this study was to check whether the data recorded by a bicycle computer paired with typical measurement sensors can be useful for a scientific evaluation of the cyclist–bicycle anthropotechnical system, including electric bicycles. The problem arose when the authors searched for methods to assess the energy efficiency of electric bicycles and intelligent power management systems provided by the assistance system, in accordance with the current needs of the bicycle user. This can be of great importance in the efficient use of electric bicycles and their batteries, in the event that they are rented in public access systems. This article focuses primarily on data on bicycle speed, calculated by the GPS module or obtained from speed sensors, as well as data from the cadence sensor, power measurement, pedaling technique and heart rate. An attempt was made to evaluate the correctness and consistency of the data recorded by the computer through various types of comparatives analyses. The conducted research used data recorded when traveling the same route with various bikes, including electric ones, with and without assistance. This is the second part of the research. The first part focusing on data obtained by a computer from a GPS system and a barometric altimeter was published in an earlier article. In both parts, the authors presented some advantages and disadvantages of using bicycle computers as tools for measuring and acquiring data. In general, it seems that the existing technology used by bicycle computers and the measurement sensors that cooperate with it can be used in the development of a system that optimizes energy consumption.

Changes in the Trunk and Lower Extremity Kinematics Due to Fatigue Can Predispose to Chronic Injuries in Cycling.

Kinematic analysis of the cycling position is a determining factor in injury prevention and optimal performance. Fatigue caused by high volume training can alter the kinematics of the lower body and spinal structures, thus increasing the risk of chronic injury. However, very few studies have established relationships between fatigue and postural change, being these in 2D analysis or incremental intensity protocols. Therefore, this study aimed to perform a 3D kinematic analysis of pedaling technique in a stable power fatigue protocol 23 amateur cyclists (28.3 ± 8.4 years) participated in this study. For this purpose, 3D kinematics in hip, knee, ankle, and lumbar joints, and thorax and pelvis were collected at three separate times during the protocol. Kinematic differences at the beginning, middle, and end of the protocol were analyzed for all joints using one-dimensional statistical parametric mapping. Significant differences (p < 0.05) were found in all the joints studied, but not all of them occur in the same planes or the same phase of the cycle. Some of the changes produced, such as greater lumbar and thoracic flexion, greater thoracic and pelvic tilt, or greater hip adduction, could lead to chronic knee and lumbar injuries. Therefore, bike fitting protocols should be carried out in fatigue situations to detect risk factor situations.

Metabolic power and efficiency for an amputee cyclist: implications for cycling technique.

Cycling technique is steeped in cultural lore. One deeply held belief is that "pulling up" to lift the leg (increased muscular leg flexion) will optimize technique and improve efficiency. In contrast, scientific evidence suggests that when cyclists are instructed to pull-up efficiency decreases. However, such interventions may not have allowed sufficient time for cyclists to adapt and refine their technique. This case study documented how a cyclist with a complete unilateral limb amputation consumed metabolic power to produce mechanical power during single-leg cycling. The cyclist was a four time US National Paralympic Champion who performed single-leg cycling for 7 yr and thus was fully adapted to pull up. We hypothesized that a counterweight system, which reduced the requirement to pull up, would decrease metabolic power and increase efficiency for this cyclist. The cyclist performed submaximal cycling (100, 135, 170, 205 W, 80 rpm, 5 min) with and without a counterweight (10 kg) on the unused crank. Expired gases were measured, and metabolic power and gross efficiency were calculated. Metabolic power decreased on average by 87 ± 7 W (P < 0.001) and gross efficiency increased from 16.3 ± 1.9 to 18.0 ± 1.8% (P < 0.001) when cycling with the counterweight. During counterweighted single-leg cycling, the metabolic power of unloaded cycling decreased (317 vs. 238 W) and delta efficiency was similar (25.2 vs. 25.5%). Results demonstrated that significant metabolic power was associated with pulling up to produce muscular leg flexion power even in a cyclist who pulled up substantially during cycling. Our findings confirm observations from previous studies that altered pedaling technique acutely and indicate that pulling up during cycling is less efficient.NEW & NOTEWORTHY This study offers unique insight into pedaling technique and provides the "final nail in the coffin" to the notion that pulling up improves cycling efficiency. When the requirement for pulling up was reduced with the counterweight, the cyclist immediately benefited as the cost to move the limb decreased and gross efficiency increased. These case study results along with previous research suggest that, in general, cyclists should not adopt pedaling techniques, which increase the action of pulling up.

The effect of chain-ring systems on the performance and pedalling technique in BMX elite and cadet riders

BACKGROUND: Sprinting at the start of a BMX race is considered one of the most important determinants of performance. Therefore, different devices and technologies have been developed to improve this ability to sprint, such as non-circular CR (CR) systems. OBJECTIVE: To compare new pedalling performance determinants for the first meters of the acceleration phase in BMX, with two different CR systems, circular and non-circular, in Elite abd Cadet cyclists. METHODS: Two level of BMX cyclists of the Spanish national team – Elite (n= 7), and Cadet (n= 7) – performed two sprints with different CR conditions (circular and non-circular). Each condition was performed in ecological BMX race conditions. Total distance (m), reaction time (s), power output (W) and the ratio between the powers of 90 and 270∘ (local extrema) and the powers at 0 and 180∘ (dead centres) of the pedalling (%PM) were analysed. RESULTS: In Elite group, no differences were found between circular and non-circular CR in total distance, reaction time, and %PM. In the Cadet group, differences were found between circular and non-circular CR conditions in %PM (p= 0.02), resulting in better results for the circular CR. In addition, no differences in total distance and reaction time were found. CONCLUSIONS: The use of non-circular CR system does not result in performance improvement in either Elite or Cadet cyclists.

ILIOTIBIAL BAND SYNDROME IN CYCLING: A COMBINED EXPERIMENTAL-SIMULATION APPROACH FOR ASSESSING THE EFFECT OF SADDLE SETBACK.

Despite abundant literature, the treatment of iliotibial band syndrome (ITBS) in cyclists remains complicated as it lacks evidence-based recommendations. The aim of this study was to develop a musculoskeletal modelling approach that investigates three potential biomechanical determinants of ITBS (strain, strain rate and compression force) and to use this approach to investigate the effect of saddle setback. Cross-sectional. An existing 3D lower-body musculoskeletal model was adapted to cycling and to the computation of three putative pathomechanisms responsible for ITBS: ITB strain, ITB strain rate, and compression force between ITB and the lateral femoral epicondyle (LFE). Lower limb kinematics recorded from ten well-trained healthy cyclists served as input data of the model. Cyclists pedalled at a steady state (90rpm and 200W) on an ergometer, and three different saddle setback conditions were tested. The theoretical combined influence of hip and knee joint angles on ITBS was investigated and analysed through the lens of individual pedalling technique. ITB-LFE compression force was the only parameter significantly affected by saddle setback and supports the hypothesis that compression force is likely to be a determinant factor in ITBS etiology. Furthermore, results showed that ITB-LFE compression force increases in individuals whose pedalling technique exacerbates hip extension-adduction and/or knee extension-internal rotation. This approach has the potential to be advantageously implemented as an additional tool to help diagnose/correct potentially harmful sport techniques and optimize equipment setup/design. 3b.

Effect Of Pedaling Feedback On 20-km Time Trial Gross Efficiency And Power Output

INTRODUCTION: Gross efficiency (GE) is a crucial factor in endurance cycling performance. Elite cyclists have superior pedaling technique, sustaining a greater average power output (PO) through the pedaling cycle than non-elite cyclists. Previous studies have demonstrated that pedaling technique can be improved with visual feedback (FB), however, the effect of pedaling feedback on GE and PO has not been investigated. PURPOSE: Determine the effect of FB from pedaling technique software on GE and PO during a 20-km time trial completed with feedback (WF) and without feedback (WO). METHODS: Eight recreationally-trained males (39 ± 6 y, VO2peak: 47.5 ± 6.1 mL·kg-1·min-1 at 282 ± 43 W) with at least six months of consistent cycling or triathlon training completed three 20-km TT. The first TT served to familiarize subjects with the FB software and cycle ergometer. During the other two sessions, subjects completed the time trial in the fastest time possible in both WF and WO conditions completed in randomized order. For WF, subjects received feedback regarding the smoothness of their pedal stroke cycle and attempted to optimize their pedaling technique real-time. Both GE and PO were calculated at 25, 50, 75, and 100% completion time. Statistical analyses of GE and PO for all stages of both WO and WF were completed using a 2x4 repeated measures ANOVA. RESULTS: GE and PO tended to be greater in all stages of WF when compared to WO (GE: 25%: 20.2 vs. 19.1%, 50%: 19.0 vs. 16.9%, 75%: 19.0 vs. 17.1%, 100%: 19.7 vs. 19.0%) (PO: 25%: 195 vs. 194 W, 50%: 203 vs. 171 W, 75%: 203 vs. 195 W, 100%: 221 vs. 213 W), but none were statistically significant (GE p = 0.084, PO p = 0.119). The biggest differences in GE and PO between the WF and WO conditions were at 50 and 75% completion. CONCLUSIONS: The monitoring of pedaling technique with FB of pedaling technique during a 20-km TT may lead to an improvement in GE without a reduction in PO during a single session using FB.

The use of accelerometry to evaluate the BMX cycling starting hill. Effect of the Q-Ring™ on the acceleration profile

ABSTRACT Accelerometers are becoming popular in sport performance, as they are easy to wear, affordable, and usable in the field. Eccentric chainrings have been commercialised to improve pedalling performance, but little is known about their possible effects in the first pedal strokes (PS) of maximal sprint starts. To analyse the effects of the Q-Ring chainring (Q) on pedalling mechanics and performance in the BMX starting hill, 12 Spanish-National-Team BMX athletes performed 3 maximal sprints comparing Q vs No-Q. Time was measured in the first three meters. Acceleration output was registered with a triaxial 6 g accelerometer (200 Hz) in the first four PS. Discrete time, acceleration and statistical parametric mapping (SPM) were used to compare between conditions. Q showed no improvement in performance, despite a force-application time increasing (p = 0.013, ES = 0.39) and a reduction in the dead spot time (p = 0.028, ES = −0.73). Time after the four PS was greater (p = 0.006, ES = 0.63), and 3-m time did not change. Likewise, SPM 1D comparison showed no differences along the four PS. Therefore, accelerometry confirms its potential to evaluate pedalling technique in BMX, where Q-Ring fails to improve the pedalling mechanics in the starting hill.

The Prolonged Touch: Finger Pedaling and Legatissimo in Classical and Early Romantic Piano Music

The term prolonged touch comes from Carl Czerny and is synonymous with finger pedaling, legatissimo, overlegato, and, in some cases, legato. This was a common technique used by the early pianists who took it out of the practices of harpsichord, clavichord, and organ playing. Its use in piano music declined during the Romantic period and beyond, due to the development of the piano and its sound, the advancement of damper pedal technique, and a more "literal” reading of notation. My research aims to understand how and where in music the prolonged touch was used in Classical and early Romantic piano music. Passages describing this technique were found in treatises and works by C. P. E. Bach, Türk, Milchmeyer, Adam, Hummel, Moscheles, Czerny, and more. From these passages, I examined the ways the aforementioned composers notated or indicated the use of this technique in their compositions. Next, based on what the treatises tell, I organized categories of musical applications of the prolonged touch. And then I gave examples from piano literature to further illustrate their use within each category. Finally, I demonstrated my artistic use of the prolonged touch in Mozart’s Sonata in F major, K. 332.

Strategies for improving the pedaling technique.

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"). 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. 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. 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.

Evaluation of the benefits in assisting cyclists to perform the pedal movement with real-time augmented feedback

Purpose of the study was to investigate the influence of training with augmented feedback of the pedal forces on performing the pedal movement on a bicycle ergometer. The aim was (1) to assist cyclists in optimizing their pedal technique and (2) to improve their perception of the execution of the pedal movement. 21 male sport students (28.1 ± 3.8 years), randomly divided in three groups: no feedback (nF), visual feedback (vF) and audiovisual feedback (avF), completed four tests in two training sessions. The Wattbike cycling ergometer measured pedal forces and provided them as vF or avF. Also the participants’ subjective perception was requested. All groups reduced the amplitudes of force and power output, with the avF group showing the greatest change. There were improvements in the overall shape of the pedal cycle with avF which is reflected in a rounder and more consistent shape, and balanced between each leg (strong pushing and balanced pulling phase). Individual statements underline the possibility of a quick modification of the pedal technique after two training sessions with feedback. Most of the participants in the avF group could imagine a general use of the sound in regular training for assistance.

Improving the Pedal Force Effectiveness Using Real-Time Sonification

The pedal force effectiveness, an important parameter in cycling performance, is rarely optimal. Decreased power is generally observed during the recovery phase (the cyclist does not pull enough). An essential part of training for cyclists consists in improving pedaling technique. Visual feedback can be useful but may not be feasible in real life, where the cyclist has to visually focus on the road. We propose auditive feedback as a better way to help cyclists improve their pedal force effectiveness in real-time. In this study, both competitive cyclists and non-cyclists tested different online sonification strategies of force effectiveness, comparing them to a silent control. The ”Squeak” strategy, generating a squeak when torque was negative, had the most positive impact on Torque Effectiveness: some participants managed to eliminate any negative torque for a full minute.

The Effect of 30-Second Sprints During Prolonged Exercise on Gross Efficiency, Electromyography, and Pedaling Technique in Elite Cyclists.

Cycling competitions are often of long duration and include repeated high-intensity efforts. To investigate the effect of repeated maximal sprints during 4 hours of low-intensity cycling on gross efficiency (GE), electromyography patterns, and pedaling technique compared with work-matched low-intensity cycling in elite cyclists. Twelve elite, male cyclists performed 4 hours of cycling at 50% of maximal oxygen uptake either with 3 sets of 3 × 30-second maximal sprints (E&S) during the first 3 hours or a work-matched cycling without sprints (E) in a randomized order. Oxygen uptake, electromyography, and pedaling technique were recorded throughout the exercises. GE was reduced from start to the end of exercise in both conditions (E&S: 19.0 [0.2] vs 18.1 [0.2], E: 19.1% [0.2%] vs 18.1% [0.2%], both P = .001), with no difference in change between conditions (condition × time interaction, P = .8). Integrated electromyography increased from start to end of exercise in m. vastus lateralis and m. vastus medialis (m. vastus medialis: 9.9 [2.4], m. vastus lateralis: 8.5 [4.0]mV, main effect of time: P < .001 and P = .03, respectively) and E&S increased less than E in m. vastus medialis (mean difference -3.3 [1.5]mV, main effect of condition: P = .03, interaction, P = .06). The mechanical effectiveness only decreased in E&S (E&S: -2.2 [0.7], effect size = 0.24 vs E: -1.3 [0.8] percentage points: P = .04 and P = .8, respectively). The mean power output during each set of 3 × 30-second sprints in E&S did not differ (P = .6). GE decreases as a function of time during 4 hours of low-intensity cycling. However, the inclusion of maximal repeated sprinting does not affect the GE changes, and the ability to sprint is maintained throughout the entire session.

Relationship between preferred saddle height and pedalling kinematics in professional cyclists

Background: Proper saddle height in cycling can improve health, comfort, and performance (Millour et al. 2019). Methods based on knee angle (KA) for saddle height adjustment are frequently employed (Ferrer-Roca et al. 2011). They are considered accurate because they consider individual differences in thigh, shank, and foot length (Bini and Hume 2016). Ferrer-Roca et al. (2011) advocate KA between 30° and 40° during maximum knee extension while pedalling to prevent injuries. However, this method does not consider ankle angle (AA) which can vary considerably according to the individual pedalling technique (Peveler et al. 2012). Purpose: The purpose of this study was to analyse lower limb joint angle of professional cyclists in their preferred saddle height. The hypothesis was that AA should be taken into consideration for an accurate adjustment of saddle height in cycling. Methods: Seventeen professional cyclists volunteered for this experiment (Mean ± SD: 28 ± 5 years old, 1.80 ± 0.05 m, 70 ± 7 kg). A 1 st step was to optimise cycling cleat position with a ML Cleat® device (Morphologics, Saint-Malo, France) and to adjust saddle and handlebar positioning according to the Morphologics ergonomist advices. Then, all the cyclists have 1 month to validate this position or to modify it according to this comfort’s feeling. In a 2 nd step, the cyclists performed a submaximal pedalling test of 3 min at 150 W and 80 rpm on their personal road bike which was mounted on an Elite Turno ergometer ® (Elite, Fontaniva, Italy) enabling to control break resistance. To measure KA, AA, and hip angle (HA) during maximum knee extension (Figure 1), markers were placed on the left side of each participant on greater trochanter, lateral femoral epicondyle, lateral malleolus, and 5 th metatarsal head. A high-resolution digital camera (Go Pro Hero 3, San Mateo, California, USA) was positioned at 4 m and perpendicular to the cyclists. Joint angles data of 10 consecutive pedalling cycles were analysed using kinematic analysis software (Kinovea V0.8.24). A correction of parallax and a correction of distortion were made with this software. Results: The results showed that the means of KA, AA, and HA were 38.0 ± 4.5°, 124.7 ± 5.2°, and 59.2 ± 3.8°, respectively. Although this mean of KA was in the range of 30°-40°, we can observe a large discrepancy between the cyclists and 5 of them had a KA outside the optimal range advocated by Ferrer-Rocca et al. (2011). Figure 2 shows that KA was positively correlated to AA (r = 0.57, p<0.01) but negatively to HA (r = 0.73, p<0.01). Discussion: Our results suggest that professional cyclists can exhibit different pedalling kinematic patterns. Athletes with higher KA present lower HA and important plantarflexion during maximum knee extension. Conversely, athletes with lower KA exhibit higher HA and large dorsiflexion during maximum knee extension. These results are in accordance with Ryan and Gregor (1992) who showed a strong inter-subject variability in pedalling kinematics of well-trained cyclists. Peveler et al. (2012) suggested that optimisation of the cycling position must take into account individual anthropometry as well as pedalling technique, and notably the foot orientation during pedalling. Cyclists who pedal with an important plantarflexion during maximum knee extension may use higher KA than those pedalling with a large dorsiflexion. Conclusion: This study suggests that saddle height adjustment optimisation should take into consideration each rider's pedalling technique, notably foot orientation, and that KA outside optimal Ferrer-Roca range is not necessarily related to a poor saddle height adjustment. Acknowledgements: MorphoLogics Company and Team Arkea Samsic.

Does changing the bike frame influence pedal force pattern in mountain bike cyclists?

In cycling, the interaction between the athlete and his bike is crucial for the resulting performance with frame geometry and bike-setup being known to affect the biomechanical and physiological outputs. Road and Olympic cross-country (XCO) bike frames are routinely used in training programs, despite having different frame configurations. The present study compared biomechanical indices of the pedalling techniques between road and off-road bike frames. Ten XCO mountain bikers of national level performed two sessions on their personal bikes. For each frame, the athletes achieved one-minute tests at 65%, 90% and 115% of their maximal aerobic power (MAP) while recording 3D pedal forces. Together with various frame and bike-setup measurements, the peak of effective force, corresponding crank angle, global and instantaneous index of efficiency were compared for Power and Frame statistical effect. The frame geometry and bike-setup showed significant differences between the road and XCO frames. The Power factor significantly ( P < 0.05) influenced the biomechanical indices of pedalling technique, but no effect of the Frame on any variable was reported. We posit that an internal reorganization was adopted by each cyclist to retrieve a specific and individual pedalling pattern regardless of the frame type. Such results can have important implications for training. En cyclisme, l’interaction entre l’athlète et son vélo est cruciale pour la performance, la géométrie du cadre et la configuration du vélo étant connues pour affecter les données biomécaniques et physiologiques. Les cadres de vélo de route et de cross-country olympique (XCO) sont couramment utilisés dans les programmes d’entraînement, malgré des configurations de cadres différentes. La présente étude a comparé les indices biomécaniques des techniques de pédalage entfre les cadres de vélo de route et de vélo tout-terrain. Dix Vététistes XCO de niveau national ont effectué deux séances sur leur vélos personnels. Pour chaque cadre, les athlètes ont réalisé des tests d’une minute à 65 %, 90 % et 115 % de leur puissance aérobique maximale (PMA) tandis que les forces 3D aux pédales étaient enregistrés. En plus des diverses mesures du cadre et de la configuration du vélo, le pic de force effective, l’angle de manivelle correspondant, l’indice global et instantané d’efficacité ont été comparés en observant les effets statistiques de la puissance et du cadre. La géométrie du cadre et la configuration du vélo ont montré des différences significatives entre le cadre de route et le cadre XCO. Le facteur de puissance ( n < 0,05) a influencé de façon significative les indices biomécaniques de la technique de pédalage, mais aucun effet du cadre n’a été rapporté, sur aucune variable. Nous supposons qu’une réorganisation interne a été adoptée par chaque cycliste pour retrouver un modèle de pédalage spécifique et individuel quel que soit le type de cadre. De tels résultats peuvent avoir des implications importantes pour l’entraînement.

Differences in Strength & Power profiles between Road and Time Trial cyclists

Introduction Within the scientific literature there is little evidence available to provide practitioners with information on strength and power profiles of cyclists, resulting in a limited understanding of neuromuscular factors related to cycling performance. Information on the legs’ elastic energy utilisation, force-velocity and length-tension curves can inform training programs and aid in talent identification. Other sports where such information is more widely available have already successfully implemented this within preparation programmes (e.g. McBride et al., 1999). Methods A total of 44 cyclists were recruited for this project, of which 15 classified in a Novice category by having no racing experience at all (age 35.5 ± 11.4 yrs; height 177.4 ± 6.5 cm; mass 77.4 ± 9.3 kg; FTP 3.28 ± 0.47 W/kg), 14 in the Road racing category as they competed for at least the past year at British Cycling Category 2 level or higher and no experience in Time-Trial (TT) races (age 35.9 ± 12.7 yrs; height 179.1 ± 6.5 cm; mass 76.6 ± 9.0 kg; FTP 3.88 ± 0.49 W/kg), and 15 in the TT category as they considered TT racing as their main competitive aim, rode in dedicated TT positions and had recently produced a 10 or 25 mile personal best of 1) for all groups. This dominance was significantly less prominent in the TT group for flexion conditions (1.35 ± 0.18) compared to Road (1.56 ± 0.22; p = 0.031) and Novice (1.53 ± 0.19; p = 0.004) groups. Joint flexion torques showed non-significant trends; they were slightly higher in the knee and lower for the hip (1.43 & 2.08 Nm/kg respectively) in TT athletes compared to Road (1.35 & 2.14 Nm/kg) and Novices (1.36 & 2.22 Nm/kg) (p = 0.429 & 0.189). No differences were found for the angle at which peak torque occurred. The velocity effect on torque production was comparable between the groups. It decreased from its peak at 30 °/s, to 82 ± 11 % of that when tested at 270 °/s for knee flexion and to 61 ± 9 % for knee extension. Hip torque reduced to 66 ± 10 % and 79 ± 10 % for flexion and extension respectively, when tested at 210 °/s compared to 30 °/s condition. Discussion The CMJ data show that cyclists – both novice and competitive – perform poorly on vertical jumping (29 ± 6 cm) compared to strength trained (48.2 ± 2.8 cm) and even untrained individuals (33.7 ± 2.3 cm) (McBride et al., 1999). This is in line with previous research on endurance type athletes showing long-distance runners to perform inferiorly on jump tasks compared to an untrained population (27.8 ± 4.3 cm vs 37.3 ± 3.1 cm; Kubo et al., 2000). In contrast to the findings by Kubo et al. (2000), the tested competitive cyclists showed lower SJ/CMJ ratios compared to the untrained controls indicating a relatively large utilisation of elastic energy storage compared to muscular power in jump performance. Based on the dynamometry testing, it seems most plausible to suggest that the reduced hip flexion capacity in TT riders results from these muscles being disused during cycling due to the extreme hip flexion angles common in their riding positions. It could be suggested that an attempt is made to compensate for this loss in hip flexion capacity through increased knee flexors’ strength. An increased knee flexor torque in TT riders could also indicate a mechanically more effective pedalling technique on the bike, as previous literature has linked hamstring activity with increases in Index of Force Effectiveness on the bike (Bini et al., 2013). Greater separation between tested groups might have been masked due to variation in preferred bike setup within the groups, TT riders also training in road setups and novice cyclists having undergone minor adaptations through recreational cycling activities. Based on these results, it seems appropriate to advise strength training to be tailored to the type of competition a cyclist is aiming to perform on. TT riders should focus on knee flexor strength, while road cyclists could benefit from a more balanced approach between hip and knee strength. Currently ongoing research is investigating how these strength characteristics relate to determinants of cycling performance in order to further help optimising training protocols and talent identification strategies. References Bini RR, Hume P, Croft J, Kilding A. (2013) J Sci Cycl, 2(1), 11-24. Kubo K, Kanehisa H, Kawakami Y, Fukunaga T. (2000). EJAP, 81(3), 181-187. McBride JM, Triplett-McBride T, Davie H, Newton RU. (1999). J Biom, 32(10), 1021-1026. Cuk I, Markovic M, Nedeljkovic A, Ugarkovic D, Kukolj M, Jaric S. (2014). EJAP, 114(8), 1703-1714.