Prediction of track performance in competitive BMX riders using laboratory measures

Identifying key physiological factors is essential in cycling; however, the unique nature of BMX decreases the validity and transferability of research findings from other cycling disciplines. Therefore, this study highlighted the physical and physiological characteristics of BMX riders that could influence track performance. Fifteen sub-elite BMX riders (male n = 12; age 18.3 ± 3.3 and female n = 3; 17.7 ± 5.7 years) undertook a battery of laboratory tests on three different occasions, including body composition, upper and lower body strength, flexibility, sprint and aerobic capacity measures. On a separate day, participants completed three full lap sprints on an outdoor BMX track. Correlation and multiple linear regression analyses were performed to develop predictive models of performance across the laboratory tests and race time. The final model indicated power to weight ratio, relative back-leg-chest strength and arm span explained ~87% of the variability in finish time (adjusted R2 = 0.87, p < .01). These findings highlighted the importance of a multidimensional approach for developing BMX race performance. Coaches should prioritise these variables in their training programs and selection of future talents. However, further physiological and biomechanical investigation is needed to validate current findings, particularly among elite riders.

Pacing strategy during Olympic Cross-Country Mountain Bike: effects of performance level, age and sex

Objectives: the aim of the present study was to verify the pacing strategy during a season of a Cross-Country Mountain Bike (XCO-MTB) and the effects of performance level, age and sex. Method: Overall, 802 paces in 4 age-sex categories were analyzed: male elite (EliteM; n = 272), female elite (EliteF; n = 170), male under-23 (U23M; n = 247) and female under-23 (U23F; n = 113). Races were divided into Initial Lap; middle one (Middle1); middle two (Middle2) and Final Lap. The athletes were divided into high performance (HP); intermediated performance (IP) and low performance (LP). The magnitude-based inference and the effect size were assessed to check the changes clinically important. Results: it was observed a similar fast-start strategy for all categories. Both HP EliteM and EliteF athletes showed higher speed in Final Lap than LP (EliteM - ES = 0.5; 90%CI -0.8 to -0.2; very likely and EliteF - ES = 1.0; 90%CI -1.4 to -0.6; almost certain). The U23F athletes showed higher speeds in Initial Lap than EliteF (ES = 0.21; 90%CI - 0.1 to 0.5; likely), however in Final Lap the speeds was lower in U23F (ES = 1; 90%CI -1.3 to -0.6; very likely). Conclusion: the fast-start strategy is typically used during a XCO-MTB race independently of performance level, age or sex. HP Elite athletes are able to maintain higher speeds in the Final Lap. U23F athletes used to do a more variable pacing strategy with more aggressive fast-start strategy and lower speed in Final Lap than EliteF.

Acute effect of foot orthotics on drag area and perceived comfort in cyclists affected by an anatomic asymmetry in time trial position

The aim of this study was to analyse the acute effect of biomechanical foot orthotics on drag area (ACd) and perceived comfort in elite cyclists affected by a lower limb length inequality (LLLI) in TT position. Twenty-nine cyclists performed two discontinuous incremental exercises (before and after orthopaedic correction) using their personal TT bicycle and equipment on a 250-m indoor velodrome. The ACd was unchanged in both the test group (TG) (‑0.5%, p = 0.707) and the control group (CG) (-1.4%, p = 0.276), whereas the perceived comfort was improved in the TG (+6.2%, p = 0.002) and stabilised in the CG (+0.7%, p = 0.546), after the fitting of the foot orthotics. Pelvis movements were decreased (small effect size) in the TG (-6.2%, p = 0.093, ES = 0.251), whereas they were increased (small effect size) in the CG (+5.2%, p= 0.159, ES = 0.215). TT position was slightly improved by compensating for a LLLI, as the ACd was stabilised and the level of comfort was improved. Thus, cyclists affected by a LLLI are recommended to compensate with foot orthotics in order to improve their level of comfort and consequently their performance in TT position.

Effect of Q-factor manipulation via pedal spacers on lower limb frontal plane kinematics during cycling

Anecdotal evidence suggests that frontal plane kinematics of the lower extremity are an important aspect of bicycle fit, however, frontal plane adjustments are often overlooked during common fitting procedures. The purpose of this study was to manipulate Q-factor width via pedal spacers to determine their influence on frontal plane kinematics of the hip, knee, and ankle during cycling. Twenty-four young healthy recreational cyclists (12 female) completed five minutes of pedaling at their preferred cadence and power output under three stance widths conditions: no spacer, 20 mm spacer, and 30 mm spacer. For each participant, the pedaling cadence and power output were kept identical for all experimental conditions. Lower extremity marker position data were captured at 250 Hz for the last two minutes of each condition. Sixty consecutive crank cycles were analyzed to identify maximum and minimum hip, knee, and ankle angles in the frontal plane. With an increase in Q-factor, hip and knee maximum abduction angles increased and maximum adduction angles decreased. With increase in Q-factor from no spacer to 20 mm spacer condition, hip abduction increased by 0.8o (∆10%; p<0.001) whereas hip abduction decreased by 0.9o (∆23%; p<0.001) and similarly, knee abduction increased by 1.2o (∆60%; p=0.002) whereas knee abduction decreased by 1.1o (∆18%; p=0.003). And with increase in Q-factor from no spacer to 30 mm spacer condition, hip abduction increased by 1.4o (∆18%; p<0.001) and hip adduction decreased by 1.6o (∆40%; p<0.001) and similarly, knee abduction increased by 1.8o (∆86%; p<0.001) and knee adduction decreased by 2.1o (∆35%; p<0.001). Maximum and minimum ankle angles were not affected by the stance width conditions (p>0.05). Pedal spacers are an effective way of manipulating Q-factor and frontal plane kinematics of the hip and knee and could help cyclists experiencing medial or lateral knee pain.

Variability of ankle kinematics in professional cyclists: consequence on saddle height adjustment

Bike-fitting methods based on the knee kinematics have been developed to determine the optimal saddle height. Among them, the Ferrer-Roca method advises a knee angle between 30 and 40° in the sagittal plane when the crank arm is aligned with the seat tube while pedalling. However, the foot orientation varies between individuals and can influence the knee angle throughout the pedalling cycle. The objective of this study was to measure the inter-individual variability in joint kinematics of professional cyclists and to evaluate the influence of the ankle angle modification on the knee angle during pedalling. Seventeen professional cyclists performed a 3-min pedalling test at 150 W and 80 rpm on their personal road bike mounted on an Elite Turno® ergometer (Elite, Fontaniva, Italia). The knee and ankle angles were measured using 2D kinematic analysis. The average knee angle (38°) was in the optimal range of 30–40°, but great variability was observed between individuals (coefficient of variation of 11.8% and 9.4% for knee and ankle angles, respectively). Moreover, five of them had a knee angle greater than 40°. In addition, their ankle angle was 15% lower than that of cyclists who had a knee angle between 30 and 40° (50 ± 4° vs. 58 ± 4°, p < 0.05). The results suggest that the knee angle observed when professional cyclists use their preferred saddle height varies among individuals and is related to the foot orientation while pedalling. The maximum knee extension angle is lower for the cyclists who accentuate the dorsiflexion but greater for those who pedalled with a plantarflexion. This implies that the saddle height adjustment method based on the knee kinematics while pedalling should consider both the knee and ankle angles.

Effect of cycling shoe cleat position on biomechanical and physiological responses during cycling and subsequent running parts of a simulated Sprint triathlon: a pilot study

Proper cleat adjustment improves cycling performance and prevents knee injuries. Recommendations have included positioning the first metatarsal head above the pedal spindle or slightly forward, but mid-foot cleat positions could be more appropriate in triathlons at constant load for their impact on the subsequent running performance. We evaluated the impact of antero-posterior cleat position on biomechanical and physiological variables during the cycling and running parts of a simulated Sprint triathlon. Seven participants performed two 32-min cycling tests including 8 sets of 3 min 30 s intervals performed at just below the power output at the first ventilatory threshold interspersed with 30 s sprints at > 100% of the maximal aerobic power. The cycling exercises were immediately followed by a maximal running performance of 20 min. The tests were performed with a 5-mm backward (BCP) and a 5-mm forward (FCP) first metatarsal cleat position. The BCP decreased the energetic cost during running (5.9%; p = 0.04; effect size [ES] = 0.92) despite no significant performance change in the cycling or the subsequent running tests. Moreover, the BCP resulted in a lower soleus recruitment during sub-maximal intensity (7.0%; p < 0.05; ES = 1.23) and of the gastrocnemius medialis (25.0%; ES = 1.00; p < 0.05) and tibialis anterior (11.9%; ES = 1.51) during the subsequent running. However, we observed much higher recruitment of the soleus (8.8%; ES = 1.36), vastus lateralis (10.1%; ES = 1.37), biceps femoris (12.0%; ES = 1.45), tibialis anterior (16.4%; ES = 3.35), and overall lower limb (11%; ES = 0.92) during sprints with the BCP. Therefore, the BCP could be more suitable in triathlons by being more economical for subsequent running despite the greater muscle activity during the cycling sprints, which form an important part of the cycling portion of Sprint triathlons.

Editorial: How do you diagnosis and manage sports-related concussion (SRC) in road cycling? A Plan for developing SRC-assessment and management protocols within road cycling

Sports-related concussion (SRC) is a common injury within elite road cycling and SRC is typically assessed and managed with a SCAT5. However the SCAT5 cannot be applied to road cycling in its current format and the cycling community therefore need to consider modifications or indeed alternatives to the SCAT5 to allow adequate assessment and management of SRC within road cycling. Potential solutions to consider to improve SRC assessment and management in road cycling include: 1) a SRC consensus meeting to allow modification of the SCAT5 for road cycling; 2) rule alterations to allow ‘pitch-side’ SRC assessment during races; 3) epidemiological injury surveillance within road cycling to better understand the issues around SRC; and, 4) better use of technologies to help diagnose SRC. We hope that these solutions can go some way to bridging the gap between SRC assessment and management between our own sport of road cycling and those with maturing SRC protocols, such as rugby union.

Predicting Bicycle Theft in Milan (IT) An Aoristic Analysis

Local administrations keep creating policies to promote cycling among citizens. However, these initiatives seem to be often counterproductive for the targeted objectives because of the increase opportunities for bike-theft. So, this research aimed at exploring Milan (IT) as a case study to address temporal distribution of bike-theft at the meso-level while controlling for seasonal variation. The occurrence of certain timeframes was evaluated against the distribution of bicycle theft between 2011 and 2015 and predictive risk effects were estimated using the Aoristic analysis. The latter provided a temporal weight and gave an indication of the probability that the events occurred within a defined period between 2016 and 2018. Within this timeframe, the Aoristic analysis showed a higher level of risk stemming from specific days of the week and times of the day, which indeed were responsible of 76% of the registered bike-thefts. The results of this study point to temporal elements that need to be taken into consideration while formulating policies that promote an urban crime-controlled environment for cyclists in Milan. Indeed, since many common crimes are aoristic, techniques such as the Aoristic analysis is crucial for ensuring an effective deployment of resources at the right time to prevent crime.

Adaptation and validation of a test to measure Greek elementary students’ basic cycling skills

The aim of this study was to adapt a previously developed test to gain a detailed insight into the cycling skills of Greek children and examine the impact that gender, age and cycling experience have on cycling skills. Students (n=80) from a local elementary school in Attica region (Greece) took the adapted cycling skills test consisting of 12 test stations. An exploratory factor analysis was conducted to investigate the factor structure of the cycling test. Descriptive statistics were performed on children’s cycling skill scores. Furthermore, independent sample t-tests and Pearson r correlations were executed to evaluate individual correlates of cycling skills. Two factors were extracted: the ‘during cycling skills’ and the ‘attention/handling cycling skills’ factor. Most children faced difficulties for skills that required more advanced attention skills and while cycling over obstacles. No significant differences in separate factors, as well as the overall cycling skill, were noted between boys and girls. Significant correlations were observed between years of cycling experience and cycling skills, while age was not correlated to these factors. The 12-item test battery adapted in the present study is suitable for the evaluation of cycling skills of Greek elementary students. Implications of the current research are further discussed.

The reliability of physiological and performance data obtained during a long distance simulated triathlon laboratory test

The aim of this study was to investigate the reliability of a newly developed long distance (LD) simulated triathlon for testing performance and physiological changes in LD triathletes. Ten trained LD triathletes (mean ± standard deviation: age 34.1 ± 5.0 years, body mass 69.07 ± 13.89 kg) completed two separate trials of a simulated LD triathlon consisting of a 1500 m swim, a 60 minute cycle at 60% of power at VO2max and a 20 minute run at 70% of velocity at VO2max. Performance (time, pace, power and rating of perceived exertion) and physiological (economy of movement (oxygen cost and energy consumption), blood lactate and heart rate)variables were measured throughout the simulated LD triathlon. Coefficient of variations (CV %) and intra class correlation coefficients (ICC) were calculated to determine reliability. The current study displayed a high level of reliability, with moderate to excellent ICC measurements for performance and physiological variables (ICC 0.62 – 0.99). All physiological variables, except blood lactate, demonstrated CV values < 10%. In conclusion, the newly developed LD simulated triathlon has a high level of task representation for LD triathletes and can accurately assess performance changes in a research setting.