Young Cyclists Research Articles

The effect of age on heart rate variability indices during and following high-intensity continuous exercise in masters and young cyclists.

This study compared heart rate variability (HRV) parameters of cardiovascular autonomic regulation between well-trained masters and young cyclists at rest, during and following a continuous cycle (CTS) protocol. Ten masters (age = 56 ± 5years) and eight young (age = 26 ± 3years) cyclists completed a 100min experimental protocol consisting of a 60min CTS cycling bout at 95% of Ventilatory Threshold 2 followed by 40min of supine recovery. Beat-to-beat heart rate was measured continuously, and HRV parameters analysed at standardised 5min intervals during rest, exercise and recovery. The root mean square of the successive differences (RMSSD), low-frequency power and high-frequency power parameters were corrected by division of the R-R interval (time domain), or R-R interval squared (frequency domain). Further, the RMSSD and RMSSD:RR for successive 60-s R-R intervals at the onset (0-10min) and offset (60-70min) of CTS exercise were analysed over 10-min periods. The natural logarithm (Ln) of skewed parameters was taken for analysis. Significant interaction effects (P < 0.05) for 5min segments were found for (LnRMSSD, LnRMSSD:RR, LnHF and LnHF:RR2. Masters cyclists demonstrated lower values of parasympathetic activity at rest and during recovery (15-20min and 35-40min) compared to younger cyclists. However, similar HRV responses were observed during exercise, including throughout the acute onset and offset periods (P > 0.05). This data shows that cardiac autonomic regulation during, or immediately following CTS exercise may not be influenced by age, but masters athletes may exhibit a lower baseline for parasympathetic activity.

Promoting (Safe) Young-User Cycling in Russian Cities: Relationships among Riders’ Features, Cycling Behaviors and Safety-Related Incidents

Background: Promoting cycling, walking and other ‘active’ transportation means continues to be a shared guideline in urban planning, closely aligned with the Sustainable Development Goals of the United Nations. Nonetheless, young cyclists’ safety figures and their potential contributors, including behavioral issues, remain an ongoing concern for researchers, practitioners, and policymakers. Aim: This study aimed to analyze both risky and protective riding patterns of young Russian cyclists in relation to cycling safety factors using the Cycling Behavior Questionnaire (CBQ). Methods: This study used the data provided by 374 young Russian cyclists, aged M = 21.6 (SD = 4.8) years, who responded to an electronic survey on cycling behavior and safety outcomes. Results: Beyond demographic characteristics, the key road rule knowledge and risk perception of young cyclists were significantly associated with their self-reported cycling behaviors. Although both traffic violations and riding errors were negatively correlated with safety incidents, predictive analyses show that errors (though not violations) play a predictive role in young cyclists’ safety-related incidents. Conversely, positive cycling behaviors have been shown to be significant reducers of riding crash likelihood. Conclusion: The results of this study support the idea that addressing key issues such as risk perception, road rule knowledge and protective riding habits, while also targeting risky behaviors on the road, could enhance cycling safety outcomes. Additionally, these findings offer valuable insights into understanding the factors contributing to riding risks and crashes among young cyclists, particularly in the context of the increasing need to promote safer and more sustainable urban mobility in a country with a still young cycling culture.

Do Risk-Taking Cyclists Have Different Sociodemographic Characteristics? An Observational Study at Intersections in a French City

The increase in cycling accidents can hinder the increased use of this transportation mode. To identify the sociodemographic factors explaining risky cyclists’ behaviors is therefore important. The relationships between some sociodemographic variables (gender, age, parenthood, use of a shared versus a personal bike) and some risky behaviors (helmet use, red-light running, crossing an intersection with a very short time before the next passing vehicle) remain inconsistent or under-investigated in the literature. These relationships were therefore investigated in a French population. Cyclists ( N = 2,788) were observed at two traffic signal intersections in the city center of Lille, France. Two cameras per site were used to score each cyclist’s variables (with a minimum of intercoder reliability = 80%). Men (versus women) and young (versus older) cyclists are less likely to wear a helmet and more likely to run red lights. Cyclists with (versus without) a child seat were more likely to wear a helmet, suggesting that parenthood influences risk perception. Shared (versus personal) bike users were found to be significantly less likely to wear a helmet and more likely to run red lights. This highlights the importance of further investigating whether shared bike users are more likely to take different types of risk on the road. Various factors (psychosocial, enforcement, road design) are discussed to explain these findings and prevent risks. The importance of adapting road safety interventions to the sociodemographic characteristics of cyclists is also discussed.

Compensatory exercises for young cyclists in the pubescents

The aim of the study was to evaluate the state of the musculoskeletal system of selected cyclists and to propose appropriate compensatory exercises, the effects of which were verified in practice. Twenty-eight MTB cyclists (men) participated in the study. They were divided into experimental (EXP) and control (CONT) groups. The Janda test, including the scaling method, was used to diagnose the condition of the cyclists' musculoskeletal system. The cyclists were tested twice after six weeks, when the experimental group was doing compensatory exercises twice a week. The results of the first and second tests were compared. The results showed a reduction in muscle mass in the arcuate neck flexion and trunk flexion tests. The results of the shortened muscle group tests showed shortening of the neck muscles and the upper part of the trapezius muscle in all the cyclists. The paravertebral back muscles and the pectoralis major muscle were shortened in 93% of the cyclists. 86% of the cyclists had shortened knee flexors and hip flexors. In the EXP, there was a significant improvement in the strength of the weakened muscle groups (p&lt;0.001) and a significant increase in the extent of the shortened muscle groups (p=0.001) after the intervention. No significant changes were found in the CONT. After the intervention programme, movement stereotypes improved significantly in the EXP group compared to the CONT group. Cyclists should regularly incorporate compensatory exercises into their current training in order to prevent overuse injuries, correct posture and eliminate back pain.

What Does It Take to Become a Professional Cyclist? A Laboratory-Based Longitudinal Analysis in Competitive Young Riders.

Laboratory-based indicators are commonly used for performance assessment in young cyclists. However, evidence supporting the use of these indicators mostly comes from cross-sectional research, and their validity as predictors of potential future performance remains unclear. We aimed to assess the role of laboratory variables for predicting transition from U23 (under 23 y) to professional category in young cyclists. Sixty-five U23 male road cyclists (19.6 [1.5]y) were studied. Endurance (maximal graded test and simulated 8-min time trial [TT]), muscle strength/power (squat, lunge, and hip thrust), and body composition (assessed with dual-energy X-ray absorptiometry) indicators were determined. Participants were subsequently followed and categorized attending to whether they had transitioned ("Pro") or not ("Non-Pro") to the professional category during the study period. The median follow-up period was 3years. Pro cyclists (n = 16) showed significantly higher values than Non-Pro riders (n = 49) for ventilatory thresholds, peak power output, peak oxygen uptake, and TT performance (all P < .05, effect size > 0.69) and lower levels of fat mass and bone mineral content/density (P < .05, effect size > 0.63). However, no significant differences were found for muscle strength/power indicators (P > .05, effect size < 49). The most accurate individual predictor was TT performance (overall predictive value = 76% for a cutoff value of 5.6W·kg-1). However, some variables that did not reach statistical significance in univariate analyses contributed significantly to a multivariate model (R2 = .79, overall predictive value = 94%). Although different "classic" laboratory-based endurance indicators can predict the potential of reaching the professional category in U23 cyclists, a practical indicator such as 8-minute TT performance showed the highest prediction accuracy.

Physiological Characteristics of Competitive Male Junior Cyclists Transitioning to the Under-23 Level: A Retrospective Comparative Study.

The purpose of the current investigation was to retrospectively assess possible differences in physiological performance characteristics between junior cyclists signing a contract with an under-23 (U23) development team versus those failing to sign such a contract. Twenty-five male junior cyclists (age: 18.1 [0.7]y, stature: 181.9 [6.0]cm, body mass: 69.1 [7.9]kg, peak oxygen uptake: 71.3 [6.2]mL·min-1·kg-1) were assigned to this investigation. Between September and October of the last year in the junior category, each cyclist performed a ramp incremental exercise test to determine certain physiological performance characteristics. Subsequently, participants were divided in 2 groups: (1)those signing a contract with a U23 development team (JUNIORU23) and (2)those failing to sign such a contract (JUNIORNON-U23). Unpaired t tests were used to assess possible between-groups differences in physiological performance characteristics. The level of statistical significance was set at P < .05 two tailed. No significant between-groups differences in submaximal (ie,gas exchange threshold, respiratory compensation point) and maximal physiological performance characteristics (ie,peak work rate, peak oxygen uptake) expressed in absolute values (ie,L·min-1, W) were observed (P > .05). However, significant between-groups differences were observed when physiological performance characteristics were expressed relative to the cyclists' body weights (P < .05). The current investigation showed that junior cyclists stepping up to a U23 development team might be retrospectively differentiated from junior cyclists not stepping up based on certain physiological performance characteristics, which might inform practitioners and/or federations working with young cyclists during the long-term athletic development process.

A brief gamified immersive intervention to improve 11–14-year-olds’ cycling-related looking behaviour and situation awareness: A school-based pilot study

Despite the health benefits of active travel, very few people in the UK choose to cycle short journeys; a frequently cited barrier is personal safety concerns. Recent research using immersive video-based training has shown promise, in terms of improving young children’s situation awareness and looking behaviour when cycling, although such evidence is sparse. We designed and delivered a brief gamified immersive intervention to address this. Forty-four schoolchildren took part in a 10-minute intervention comprising 360-degree real-world point-of-view footage of a cycle journey through a busy urban environment, experienced via a head-mounted display (HMD) with built-in eye tracking. The participants were split into two groups: an explicit learning group who received instructions regarding adaptive looking behaviour, and an implicit learning group who received no instructions. In a gamified protocol, participants scored points for fixating on target areas that represented adaptive looking behaviour; reward sounds notified them when they were successful. The explicit learning group accrued points more rapidly in the early stages of the intervention, but the implicit learning group matched the explicit group’s performance level by the end of the brief intervention. All participants’ cycling confidence increased after the brief intervention, and these increases were correlated with their performance in the game, but participants’ performance on video-based situation awareness tests did not improve. Brief gamified immersive interventions could be used to develop young cyclists’ competence, and therefore confidence, regarding cycling on roads, which could, in turn, encourage them to cycle short journeys.

Cyclists perception and self-reported behaviour towards interacting with fully automated vehicles

Fully automated vehicles (FAVs) have the potential to improve road safety and reduce traffic congestion and emissions. Most studies of acceptance of FAVs have focused on motor vehicle users, largely ignoring other road users, such as cyclists. This study investigates the factors that influence cyclists’ receptivity towards sharing roads with FAVs and their behavioural intentions in interactions with FAVs. The online survey collected information on participant demographics (e.g. age, gender, crash experience), self-reported on-road cycling behaviours (e.g. violations, errors, positive behaviours) and their receptivity towards sharing roads with FAVs (e.g. attitude, social norms, trust). Three typical cyclist-vehicle interaction scenarios were presented to test the cyclists’ intention to engage in self-protective behaviours (e.g. giving a hand signal, giving way or moving over) during the interaction with a FAV. Three hundred and fourteen Australian adults (106 females vs 208 males) who had ridden a bicycle at least once in the past year completed the survey. The results show that older cyclists and male cyclists had a lower receptivity towards sharing roads with FAVs than younger cyclists and female cyclists, respectively. Cyclists who reported being involved in a bicycle crash in the last two years and those who reported committing more errors on roads were more willing to share roads with FAVs. Cyclists who had a higher propensity to risky behaviours and positive behaviours were less likely to take intended self-protective behaviours during interaction with FAVs. Findings of the study provide some insights from the cyclist’s perspective to facilitate the development and implementation of automated vehicles.

Development of ZnO@C/GCE sensor for electrochemical determination of terbutaline in blood serum samples

This article described how ZnO and carbon nanocomposite modified glassy carbon electrodes (ZnO@carbon/GCE) were used to electrochemically identify terbutaline (TER) as a substance subject to doping restrictions among athletes. By using FE-SEM, EDS, and XRD to characterize the ZnO@carbon nanocomposite material, it was discovered that carbonaceous layers had been successfully distributed over the ZnO nanorods' surface. The voltammetric studies revealed that both ZnO/GCE and ZnO@carbon/GCE displayed an oxidation peak for TER, but the incorporation of carbonaceous layers into the ZnO nanorod structure with the necessary sensitivity and selectivity significantly improved the voltammetric response of TER in terms of both the electron-transfer reactions and electrocatalytic activity. The suggested platform (ZnO@carbon/GCE) produced results with a working concentration range of 5–720 μM and a limit of detection of 25 nM. Six separate blood serum samples from young cyclists between the ages of 21 and 29 were prepared in order to examine the practical applicability of the ZnO@carbon/GCE sensor. The results revealed impressive recovery rates between 94.75% and 99.45%, as well as excellent precision (RSD less than 5.04%). Additionally, the findings of the TER ELISA kit and DPV assays showed sufficient conformity. These results demonstrated that ZnO@carbon/GCE may be used as a reliable and accurate TER sensor to accurately quantify the TER level in blood serum samples.

Measurement of Simple Reaction Time of the Cyclist in the Laboratory and Natural Environment Condition.

The most commonly used reaction time tests within the athlete community require appropriate testing conditions and equipment, most frequently laboratory ones, which are not suitable for testing athletes in their natural environment and do not fully represent athletes' natural capabilities and the influence of the surrounding environment. Therefore, this study's goal is to compare the simple reaction times (SRTs) of cyclists during tests in laboratory conditions and in natural cycling surroundings. The young cyclists (55 participants) took part in the study. The SRT was measured in a quiet laboratory room with the use of the special device. During riding and standing with a bike outdoors, the necessary signal was captured and transmitted by a folic tactile sensor (FTS) and an extra intermediary circuit (both invented by our team member) connected to a muscle activity measurement system (Noraxon DTS Desktop, Scottsdale, AZ, USA). The results showed that external conditions significantly affect the SRT, with it being the longest when riding and the shortest if measured in an isolated laboratory room, but without an effect of gender. Typically, men have a shorter reaction time, but our result supports other observations, where people with an active lifestyle show no sex differentiation in SRT. The proposed FTS with an intermediary circuit allowed us to measure SRT with the use of non-dedicated equipment and avoid buying a new one for a single specific use.

Розвиток витривалості юних спортсменів 12-13 років у велотуризмі на початковому етапі підготовки

Мета дослідження – розробити і обгрунтувати комплексну методику розвитку витривалості школярів середніх класів засобами велотуризму. Матеріал і методи. В даному дослідженні приймали участь велотуристи 12-13 років Липкуватіської загально–освітньої школи l-lll ступенів (9 спортсменів склали експериментальну групу, 9 – контрольну). Для визначення функціональних можливостей школярів середніх класів застосовувались наступні проби і тести: Гарвардський степ-тест, проба Штанге, проба Генчі, проба Серкіна. Розроблено методику розвитку витривалості, яка передбачає застосовування комплексу засобів велотуризму. Комплекс складається з 2-х частин: комплексна дистанція «тріал і фігурне водіння велосипеда» і велопохід. Тріал являє собою дистанцію довжиною 100-200 м. з природними та штучними перешкодами (крутий схил; яр; піщані; заболочені та інші важкопрохідні дільниці; струмки; калюжі; стовбури дерев, що лежать, тощо) по вузькому коридору (до 1,5м), утвореному природними і штучними обмеженнями (стрічки між деревами або стійками тощо). Фігурне водіння велосипеда передбачає застосування наступних перешкод: «Щілина», «Змійка між стійками», «Коридор», «Колія», «Коло», «Вісімка», «Ворота», «Кільце», «Перенесення предмету», «Зигзаг», «Гойдалка», «Змійка між фішками», «Стоп-лінія. Фініш». Особливістю походу є те, що окрем розвитку витривалості, він вирішував завдання виховного та освтнього характеру шляхом ознайомлення з цікавими місцями Слобожанщини, зустрічами з цікавими людьми тощо. Результати. Показано, що авторська методика комплексного розвитку витривалості, що поєднує засоби фігурного вождіння та велопоходу, є більш ефективною у порівнянні з традиційною методикою розвитку витривалості школярів середніх класів, яка містить виключно подолання дистанцій; виявлено, що застосування комплексної методики розвитку витривалості школярів середніх класів сприяє підвищенню часу затримки дихання за пробами Штанге, Генчі, Серкіна, а також зменшенню ЧСС спокою, ЧСС після стандартного навантаження та підвищенню якості відновлення працездатності. Висновок. Розроблена методика може застосовуватись в підготовці юних велотуристів.

The Impact of a Single Exhaustive Training Session with Protein Supplementation on Muscle Damage Markers in Young Cyclists

This study aimed to investigate thei of a single exhaustive training session with protein supplementation on muscle damage markers in young cyclists. Twenty professional cyclists with experience at local and national championship levels were recruited using a convenience sampling method. They were divided into an experimental group (n=10; mean age 21.4±4.7 years; body mass index (BMI) = 20.56±2.12 kg/m2) and a placebo group (n=10; mean age 19.1±4.1 years; BMI = 21.48±3.96 kg/m2). Blood samples were collected in a fasted state to measure phospho creatine kinase (CPK) and lactate dehydrogenase (LDH) levels. The experimental group consumed a solution containing 400 mg of protein powder (100 mg per kilogram of body weight) with 400 cc of water, while the placebo group consumed a solution containing maltodextrin powder (100 mg per kilogram of body weight). A second blood sample was taken one hour after supplementation. Participants did not engage in any physical activity during the supplementation period. After a 10-minute warm-up, the Wingate test was performed, and blood samples were collected 24 and 48 hours after the test. The findings indicated that one exhaustive training session with protein supplementation did not have a significant effect on CPK (p=0.126) and LDH (p=0.526) concentrations in professional cyclists. Post-CPK and LDH concentrations were highest at 24 and 48 hours after strenuous activity. Based on this study, a single exhaustive training session with protein supplementation did not significantly impact muscle injury markers in young cyclists. Therefore, alternative nutritional recommendations and strategies should be considered.

Bicyclist Helmet Use and Distractions: An Observational Study on a Designated Urban Shared-Use Path

Distraction has been a behavior evaluated among drivers and more recently pedestrians but remains understudied among bicyclists. Demographic variables have often been used to differentiate those who are likely to be distracted. However, there are differing conclusions about demographic influences of distracted bicycling and even distraction’s relationship itself to bicycle safety. This study observed bicyclist distraction and safety behaviors, along with possible demographic factors that could predict these behaviors. The authors observed cyclists on the Elizabeth River Trail, a bicyclist/pedestrian shared trail that covers 10.5 miles of an urban area. During data collection, observers collected data about the direction the cyclist was traveling, if they were with children, if they were wearing a helmet, if a distraction was present, and the type of distraction, if applicable (e.g., hand-held use of mobile phones, wearing headphones, eating, drinking). Observers also recorded participants’ perceived sex and estimated age. Frequency analyses revealed that 55.4% of 426 cyclists were not helmeted and 30.0% were distracted. The most common distraction was wearing headphones (19.5% of total cyclists observed). No significant relationship was found between helmet use and distraction. Younger cyclists were more likely than older cyclists to not wear a helmet and be distracted. These findings show a high prevalence of behaviors that may impact safety on designated cycling paths. The significant number of cyclists without a helmet and being distracted should create concern for potential injury risks to bicyclists on trails being built within urban areas if those bicyclists were to crash.

Bunt młodych – wyzwalająca rola roweru

The text is a story about a group of boys who, by following the pedagogy of adventure, change not only themselves but also a fragment of space. Institutions of power, and society itself, expect subordination within the space in which we function. It is the authority (in whatever shape) that determines the spatial development (laws, regulations, resolutions). The same is done by people who claim the right to be called the guardians of social space, that is, the validity of the social order they postulate in the place they “occupy” (house, street, district). As a result of the interference of such people, we are dealing with a “soft” variety of a total institution. The example of young cyclists from Dirt park KrossKiller in Szczecin can show this process and the form of resistance on the part of the oppressed. It is therefore about a micro-community, which through its action, can be defined as a rebellion against the so-called guardians of space who want to create their own place on Earth, they experience an adventure, by their actions, they fit into the framework of the pedagogy of adventure. While filming and writing the text, the method of observation was used.

Doping Lives on in Running and Cycling as Young Cyclists Continue to Die.

Doping Lives on in Running and Cycling as Young Cyclists Continue to Die.

Improving children’s on-road cycling with immersive video-based training: A pilot study

Cyclists are frequent casualties in road traffic collisions, and cyclist inattention is often implicated. Children are more distractible than adults and so are arguably more vulnerable road users, including when cycling. Research shows that misallocation of attention or distraction is a common factor in crashes involving cyclists, and child cyclists are more likely to be seriously injured, possibly because their hazard perception is inferior to that of adults. Video-based training paradigms designed to improve children’s hazard perception and situation awareness have yielded mixed findings, but none have examined positive transfer of such training interventions to on-road cycling performance. The aim of this study was to use an immersive video-based training protocol to improve attention allocation, situation awareness and on-road cycling performance in children who had completed UK cycle training aimed at 9–11-year-olds. Thirty-three children aged 10–12 years were randomly allocated to either an Intervention group or a Control group. All participants reported their cycling behaviour and cycling self-efficacy, and completed online situation awareness tests at baseline, post-test, and retention stages. Between baseline and post-test, the intervention group (n = 17) completed a lab-based training protocol in which they viewed real-world cyclist point-of-view footage on an immersive screen while pedalling on a stationary cycle. As they navigated five virtual routes their task was to demonstrate awareness of potential hazards and other information pertinent to their safety, with decreasing levels of support from the researcher as they progressed. The control group did not receive the training intervention. All participants’ cycling performance was individually assessed on urban roads on two testing occasions, by qualified cycle instructors. The intervention group outperformed the control group in terms of their on-road performance, in terms of Making good and frequent observations (Observation; F[1,31]) = 16.53, ηp2 = 0.35, p = 0.0003,); Communicating intentions clearly to others (Communication; F[1,31]) = 13.70, ηp2 = 0.31, p = 0.001); Choosing and maintaining the most suitable riding positions (Position; F[1,31]) = 7.41, ηp2 = 0.19, p = 0.01); and Understanding priorities on the road, particularly at junctions (Priorities; F[1,31]) = 6.88, ηp2 = 0.18, p = 0.01), although this was not accompanied by significant changes in their cycling self-efficacy and situation awareness, all p’s > 0.05. The present findings suggest that an immersive video-based protocol such as the one herein may improve children’s safety when cycling on roads and may therefore be an effective complement to current cycle training protocols. Given ongoing governmental investment in cycling infrastructure in the UK, with a concomitant increase in micromobility modes of active travel, national policy will need to consider the additional perceptual-cognitive demands that will face young cyclists; immersive training is a potentially efficient and cost-effective way to mitigate these demands. However, further research attention should be devoted to the development of effective situation awareness tests – preferably ones that correlate with, if not predict, children’s independent on-road cycling performance.

Is Motor Coordination the Key to Success in Youth Cycling?

To evaluate the predictive value of a (non-)sport-specific test battery on the future success of young cyclists, test scores were compared with competition performances 2-3years later. Three motor coordination, 5 physical performance, and 2 cycling-specific measurements were collected in 111 U15 (13.0-14.9y) and 67 U17 (15.0-16.9y) male road cyclists. In addition, maturity status, relative age, and competition history were assessed. National and provincial competition results 2-3years later, in the U17year2 and U19year2 categories, were submitted to 2 separate 4-stage hierarchical regressions. The results of the model of the U15 group revealed that maturity, relative age, competition history, motor coordination, physical performance, and cycling-specific performance accounted for 22.6% of the variance in competitive success. For the U15 category, only maturity and motor coordination were significant predictors of competitive success in the U17year2 category. Maturity and motor coordination each uniquely explained ±5% of the variance. However, for the U17 group-neither motor coordination, physical performance, nor cycling-specific performance could predict competitive success in the U19year2 category. The current study underlines the importance of general motor coordination as a building block necessary for optimal development in youth cycling. However, considering the lack of predictive value from the U17 category onward, other features may determine further development of youth athletes. Nevertheless, it is questioned why athletes need to possess a minimum level of all physical, motor coordination, and cycling-specific characteristics to experience success and enjoyment in their sport.

Elite versus non-elite cyclist – Stepping up to the international/elite ranks from U23 cycling

ABSTRACT This study investigated the physiological, performance and training characteristics of U23 cyclists and assessed the requirements of stepping up to the elite/international ranks. Twenty highly trained U23 cyclists (age, 22.1 ± 0.8 years; body mass, 69.1 ± 6.8 kg; VO2max, 76.1 ± 3.9 ml·kg−1·min−1) participated in this study. The cyclists were a posteriori divided into two groups based on whether or not they stepped up to elite/international level cycling (U23ELITE vs. U23NON-ELITE). Physiological, performance and training and racing characteristics were determined and compared between groups. U23ELITE demonstrated higher absolute peak power output (p = .016), 2 min (p = .026) 5 min (p = .042) and 12 min (p ≤ .001) power output as well as higher absolute critical power (p = .002). Further, U23ELITE recorded more accumulated hours (p ≤ .001), covered distance (p ≤ .001), climbing metres (p ≤ .001), total sessions (p ≤ .001), total work (p ≤ .001) and scored more UCI points (p ≤ .001). These findings indicate that U23ELITE substantially differed from U23NON-ELITE regarding physiological, performance and training and racing characteristics derived from laboratory and field. These variables should be considered by practitioners supporting young cyclists throughout their development towards the elite/international ranks.

Clusters of Bicycle Taxi Operators and their Main Service Operation Patterns: Case Study of Quelimane, Mozambique

Bicycle taxi is a vital means of informal public transport service in most Sub-Saharan African cities, and for this reason, understanding who operates this service, and how they operate could help define initiatives to promote this service. This study considered clusters of bicycle taxi operators and their main service operation patterns. A survey was conducted among 105 regular bicycle taxi operators in Quelimane, Mozambique. Twostep cluster analysis identified homogeneous groups of bicycle taxi operators based on six socio-economic factors (age, income, education, household composition, bicycle ownership, and residence location). A Mann-Whitney U test was employed to compare pairs of clusters of bicycle taxi operators regarding a set of taxi services operation variables, such as the number of passengers carried daily, daily revenues, and service hours. Four clusters of bicycle taxi operators were identified which are, less-educated operators from large households (C1), educated migrants (C2), less-educated bicycle renters (C3), and young cyclists from small households (C4). When comparing differences in service operation patterns per cluster of bicycle taxi operators, the study showed that people in C1 produced fewer bicycle taxi trips than those in C2 and C4. For daily earnings, people in C2 earn more than those in C1 and C3. For service hours, individuals in C2 cycle long service hours when compared to those in C1, which could be harmful to their health. The result of this study could reorient bicycle taxi service promotional policies to make the service more sustainable.

MitoQ supplementation improves oxygen uptake kinetic by reduced reactive oxygen species levels and altered expression of miR‐155 and miR‐181b

BackgroundMitochondrial antioxidant (MitoQ) has been developed as a pharmaceutical for diseases. Few studies have investigated the role of MitoQ in enhancing athletic performance. Thus, the purpose of the study was to determine the effects of MitoQ supplementation to exercise training (EX) on the oxygen uptake kinetic, oxidative stress, and MicroRNAs (miRNAs) regulating vascular inflammation and reactive oxygen species (ROS) generation.Methods32 healthy young cyclists (25.6±3.8yr) were randomly divided into 4 groups (n=8); 1) Placebo, 2) EX (Cycle ergometer, moderate intensity), 3) MitoQ (20 mg/day, oral), and 4) EX+MitoQ. Oxygen uptake kinetics during low, moderate, and severe intensity cycling were measured before and after two weeks of interventions. Serum levels of ROS, glutathione peroxidase (GPx), and superoxide dismutases (SOD) were measured. miR‐19b, miR‐155, miR‐181b, and miRNA‐146a were measured by RT‐qPCR.ResultsEX+MitoQ accelerated the phase Ⅱ of oxygen uptake kinetic (moderate intensity) compared to EX (P&lt;0.05). Both EX+MitoQ and MitoQ reduced ROS levels but there was no change in EX (P&lt;0.05). GPx was increased in EX, MitoQ, and EX+MitoQ (P&lt;0.05) whereas SOD levels in all groups were not different. miR‐155 and miR‐19b expressions were decreased in EX+MitoQ compared to EX (P&lt;0.05). miR‐146a was increased in EX+MitoQ compared to EX only (P&lt;0.05). There was no difference of miR‐181b between EX and Mito+Q. Placebo effects were not found.ConclusionsA short‐term MitoQ supplementation to aerobic training enhanced oxygen utilization during a moderate performance in cyclists compared to training alone by reduced ROS levels and altered expression of miR‐155 and miR‐181b mediating vascular endothelial inflammation and ROS generation.